Common Electrical Hazards and Preventable Steps

The major hazards associated with electricity are electrical shock and fire. Electrical shock occurs when the body becomes part of the electric circuit, either when an individual comes in contact with both wires of an electrical circuit, one wire of an energized circuit and the ground, or a metallic part that has become energized by contact with an electrical conductor.

The severity and effects of an electrical shock depend on a number of factors, such as the pathway through the body, the amount of current, the length of time of the exposure, and whether the skin is wet or dry. Water is a great conductor of electricity, allowing current to flow more easily in wet conditions and through wet skin. The effect of the shock may range from a slight tingle to severe burns to cardiac arrest. Table 10.1 shows the general relationship between the degree of injury and amount of current for a 60-cycle hand-to-foot path of one second’s duration of shock. While reading this chart, keep in mind that most electrical circuits can provide, under normal conditions, up to 20,000 milliamperes of current flow.

Table 10.1 Body Reactions Under Effect of Electrical Current



1 Milliampere

Perception level

5 Milliamperes

Slight shock felt; not painful but disturbing

6-30 Milliamperes

Painful shock; “let-go” range

50-150 Milliamperes

Extreme pain, respiratory arrest, severe muscular contraction

1000-4,300 Milliamperes

Ventricular fibrillation

10,000+ Milliamperes

Cardiac arrest, severe burns and probable death

Adopted from Princeton University Environmental Health and Safety Handbook

In addition to the electrical shock hazards, sparks from electrical equipment can serve as an ignition source for flammableor explosivevapors or combustible materials.

Loss of electrical power can create hazardous situations. Flammable or toxic vapors may be released as a chemical warms when a refrigerator or freezer fails. Fume hoods may cease to operate, allowing vapors to be released into the laboratory. If magnetic or mechanical stirrers fail to operate, safe mixing of reagents may be compromised.

Electric shock

Electric shock is another hazard common to many pieces of laboratory equipment. Any electrically powered item of laboratory equipment which is subject to spillage of chemicals or water, or exhibit signs of excessive wear should be used carefully.

Electrical shocks occur when the electrical circuit completed by the part of human body. One way this can occur is by contacting a metallic part of a piece of equipment that has become energized by contact with an electrical conductor. The severity of the electrical shock depends on the following:

  • The amount of the current (given as a list above)
  • The pathway through the body
  • The duration of the exposure
  • Whether the skin is wet or dry

A victim of electrical shock could be knocked unconscious. If the victim is still in contact with the live power source, turn off the live source or press the emergency power cut off button before administering aid. Do not touch anyone that is still in contact with a live power source, as you could be electrocuted as well

After disconnecting power, administer first aid and/or call Health Center (7666).

Resistive heating

Even if an individual survives a shock episode, there may be immediate and long-term harm on tissue, nerves, and muscle due to heat generated by the current flowing through the body. The heat generated is basically resistive heating such as would be generated in heating coils in a small space heater.

The scope of the effects of external electrical burns is usually immediately apparent, but the total effect of internal burns may become manifest later on by losses of important body functions due to the destruction of critical internal organs, including portions of the nervous system, which is especially vulnerable.

If a victim has resistive heating burns; you should apply “Burn Kit”, then call Health Center (7666).

Spark ignition sources

Induction motors should be used in most laboratory applications instead of series-wound electric motors, which generate sparks from the contacts of the carbon brushes. It is vital to use non-sparking motors in pieces of equipment which result in considerable amounts of vapour, such as blenders, evaporators, or stirrers. Equivalent ordinary equipment or other items such as vacuum cleaners, drills, rotary saws, or other power equipment are not suitable for use in laboratories where solvents are in use. Blowers used in fume exhaust systems should at least have non-sparking fan blades, but in critical situations with easily ignitable vapors being exhausted, it may be worth the additional cost of a fully explosion-proof blower unit.

Any device in which an electrically live circuit makes and breaks, as in a thermostat, an on-off switch, or other control mechanism, is a potential source of ignition for flammable gases or vapors. Special care should be taken to eliminate such ignition sources in equipment in which the vapors may become confined, as already discussed for refrigerators and freezers. It is also possible in other equipment such as blenders, mixers, and ovens and the use of such devices should not be permitted with or in the vicinity of materials which emit potentially flammable vapors.

Spark ignition can cause electrical fire damage in the laboratory. In such cases; the laboratory must be evacuated and the Call Center must be called (9988).

Preventative Steps and Safe Work

Preventative steps

There are various ways of protecting people from the hazards caused by electricity, including insulation, guarding, grounding, and electrical protective devices. Laboratory users can significantly reduce electrical hazards by following some basic precautions:

  • Inspect wiring of equipment before each use. Replace damaged or frayed electrical cords immediately.
  • Use safe work practices every time electrical equipment is used.
  • Know the location and how to operate shut-off switches and/or circuit breaker panels. Use these devices to shut off equipment in the event of a fire or electrocution.
  • Limit the use of extension cords. Use only for temporary operations and then only for short periods of time. In all other cases, request installation of a new electrical outlet.
  • Multi-plug adapters must have circuit breakers or fuses.
  • Place exposed electrical conductors (such as those sometimes used with electrophoresis devices) behind shields.
  • Minimize the potential for water or chemical spills on or near electrical equipment.


  • All electrical cords should have sufficient insulation to prevent direct contact with wires. In a laboratory, it is particularly important to check all cords before each use, since corrosive chemicals or solvents may erode the insulation.
  • Damaged cords should be repaired or taken out of service immediately, especially in wet environments such as cold rooms and near water baths.

Any of the following circumstances requires that the user immediately take the equipment out of service:

  • Experiencing shocks, even mild shocks, upon contact
  • Abnormal heat generation
  • Arcing, sparking, or smoking from the equipment

Laboratory users must label the equipment, “Do Not Use” and should arrange for equipment repair either through the equipment manufacturer or through their department support as appropriate.


Live parts of electric equipment operating at 50 Volts or more (i.e., electrophoresis devices) must be guarded against accidental contact. Plexiglas shields may be used to protect against exposed live parts. Figure 10.1.a displays the safety fuse used in Sabancı University.

Figure 10.1 Safety Fuse and two-prong plug


Only equipment with two-prong plugs should be used in the laboratory. The two prong (Figure 10.1.b) provides a path to ground for internal electrical short circuits, thereby protecting the user from a potential electrical shock.

Circuit Protection Devices

Circuit protection devices are designed to automatically limit or shut off the flow of electricity in the event of a ground-fault, overload or short circuit in the wiring system. Fuses and circuit breakers prevent over-heating of wires and components that might otherwise create fire hazards. They disconnect the circuit when it becomes overloaded. This overload protection is very useful for equipment that is left on for extended periods of time, such as stirrers, vacuum pumps, drying ovens, Variacs and other electrical equipment.

The ground-fault circuit interrupter, or GFCI, is designed to shut-off electric power if a ground fault is detected, protecting the user from a potential electrical shock. The GFCI is particularly useful near sinks and wet locations. Since GFCIs can cause equipment to shut down unexpectedly, they may not be appropriate for certain apparatus. Portable GFCI adapters (available in most safety supply catalogs) may be used with a non-GFCI outlet.


In laboratories where volatile flammable materials are used, motor-driven electrical equipment should be equipped with non-sparking induction motors or air motors. These motors must meet Turkish Standard Electric Safety Code explosion resistance specifications. Many stirrers, variacs, outlet strips, ovens, heat tape, hot plates and heat guns do not conform to these code requirements.

Avoid series-wound motors, such as those generally found in some vacuum pumps, rotary evaporators and stirrers. Series-wound motors are also usually found in household appliances such as blenders, mixers, vacuum cleaners and power drills. These appliances should not be used unless flammable vapors are adequately controlled.

Although some newer items of equipment have spark-free induction motors, the on-off switches and speed controls may be able to produce a spark when they are adjusted because they have exposed contacts. One solution is to remove any switches located on the device and insert a switch on the cord near the plug end.

Safe work practices

The following practices may reduce risk of injury or fire when working with electrical equipment:

  • Keep away from the energized or loaded circuits.
  • Sources of electricity and exposed circuits must be guarded.
  • Disconnect the device from the source in the period of service or maintenance of the device.
  • Disconnect the power source before servicing or repairing electrical equipment.
  • Handling the equipment that is plugged in, if it is necessary, hands or contacting parts must be dry and, wear non-conductive gloves and insulated-soles shoes.
  • If it is safe to work with only one hand, keep the other hand away from all conductive material. This step reduces accidents that result in current passing through the chest cavity.
  • Utilization of electrical equipment in cold rooms must be minimized due to condensation issues. If it is imperative to use such areas, the equipment must be fixed on a wall or vertical panel.
  • If the device interacts with water or other liquid chemicals, equipment must be shut off power at the main switch or circuit breaker and unplugged.
  • If an individual comes in contact with a live electric, do not touch the equipment, source, cord or individual. Disconnect the power source from the circuit breaker or pull out the plug using a leather belt.

References and sources for information from the relevant websites and documentation of different universities, NGOs and government agencies used in the preparation of this website are provided at references.

Q&A / 

Patio Moss Mold and Mildew Prevention

Patio Moss Mold and Mildew Prevention | This ugly black mold and mildew on the patio can be prevented with a simple spray-on solution! (C) Copyright 2017 Tim Carter

“Moss, mold, and mildew need food to survive, just like you and me. The food sources can be an assortment of things…”

Patio Moss Mold and Mildew Prevention Checklist

  • Moss, mold, mildew, and algae feed off invisible food and water
  • Pressure washing can damage precast colored pavers and brick
  • WATCH the copper sulfate video below!
  • Copper sulfate is the secret to STOP moss, mold, algae, and mildew on your patio

DEAR TIM: My wife and I have an outdoor patio constructed with colored precast concrete paving blocks. It doesn’t take long each year for black mold and mildew to start to grow on it.

We also have an issue with moss and algae growing on it. I have to power wash it at least once a year and wonder if there’s a way to prevent the moss, mildew, and mold from growing in the first place.

Am I damaging my patio with the power washer? Why is it growing on the precast concrete pavers? This problem can’t be that hard to solve. Loren P., Okatie, SC

Related Links

Certified Organic Patio Cleaner

How to Remove Patio Algae Without Alien Help

DEAR LOREN: I used to have the same problem on two massive solid-clay brick paver patios in the back of the last house I lived in. It was a mind-numbing job that took hours and hours of work to restore the patio to brand-new condition each spring. I hated doing that job.

Why Does Patio Moss Mold Grow?

Let’s talk about why the moss, mold, and mildew grow in the first place. Many years ago, I couldn’t understand how it could grow on solid rock, precast concrete or brick, but now it’s crystal clear to me as I’ve attained more knowledge.

Moss, mold, and mildew need food to survive, just like you and me. The food sources can be an assortment of things just as we humans have countless different things we eat.

Dust, ultra-fine sugar aerosols from trees and bushes, tree sap, minerals, organic debris, etc. are all food sources for the unsightly things growing on your patio.

Free & Fast Bids

What is a Fast Test to Grow Mold & Mildew?

You can do a fast test that produces dramatic results by just pouring out a small amount of carbonated soda that contains sugar or high-fructose corn syrup on your patio. You might have mildew growing on the spill in as little as forty-eight hours if you do it in a shaded area of your patio.

Water is the only other missing ingredient needed to fuel the moss, mold and mildew since their spores are constantly falling down on your patio. If you could keep your patio completely dry, you’d not have any growth.

But even morning dew is enough to sustain the green and black organisms. They’re tenacious and know how to make a little water go a long way.

Will Power Washing Damage My Patio?

Let’s discuss power washing. There’s a raging debate in the home improvement community about whether or not power washing can be destructive to concrete, brick, precast pavers, wood, etc. The unequivocal answer is yes – it’s destructive.

©2017 Tim Carter

The rate of destructive force is directly proportional to the pounds-per-squares-inch (psi) power the machine delivers, the angle of the spray-wand tip and the distance the tip is from the surface being cleaned. You just have to look at the Grand Canyon to understand that water simply flowing over rock can do damage.

Water directed at a surface with 1,500 psi or more can do immense damage on softer surfaces and it does cumulative damage to harder surfaces with each successive washing.

Will High Pressure Remove Colored Cement?

In your case power washing will rapidly remove the colored cement paste that covers the small sand and gravel particles in your precast pavers. If you had a saved paver in your garage that the installer left behind that’s never been washed or exposed to the elements you’d notice that it’s got a uniform color over the entire surface.

This uniform color is created by an ultra-fine layer of pigmented Portland cement that coats the sand and small gravel in the pavers.

After one or more washings, you’ll start to notice the individual colors of the different sand and gravel that was used to make the pavers. The colored cement will still be there between the individual particles of sand and gravel.

How Do You Prevent Patio Moss Mold Growth?

The good news is you can prevent the growth of patio moss, mildew and mold. All you have to do is borrow technology developed hundreds of years ago by mariners.

Clipper ships and warships that depended on speed to make money and win wars employed the use of copper plates on the hulls of the ships so barnacles and other marine life would not grow on the wood below the water line.

Patio moss mold can be prevented using copper sulfate. ©2018 Tim Carter

Is Copper a Natural Biocide?

Copper is a natural biocide. It’s pure, it’s pretty much harmless to mammals and it’s found in multi-vitamins that you might take to stay healthy. Copper in our bodies helps us to retain iron and it aids in producing the energy you need to get through the day.

You can’t cover your patio with copper sheets, but you can spray on a liquid solution of copper that will soak into the top surface of the concrete pavers. This copper will stop the growth of the pesky green and black organisms in their tracks.

Do You Dissolve Copper Sulfate In Water?

The easiest way to apply the copper is to purchase copper sulfate crystals. This is readily available online and the blue crystals dissolve readily in warm or hot tap water.

This is copper sulfate. It dissolves easily in water. Spray it on with a hand-pump sprayer. CLICK THE IMAGE TO ORDER THE COPPER SULFATE NOW.

I’d mix 1.75 pounds of copper sulfate in each gallon of water. My guess is you’ll discover that two or three gallons of water is plenty to treat the average-sized patio.

Copper Sulfate Video

Watch this funky video about copper sulfate. This guy is spot on with his advice!

Is it Best to Apply To Dry Pavers, Concrete or Brick?

I’d apply the solution when the patio is dry as a bone. You want the solution to soak into the surface. Concrete is absorbent unless it has a shiny steel-troweled finish.

Most exterior concrete is rough, so the solution will soak in. Apply just enough so the pavers get nice and wet, but not so much as the solution runs off into surrounding vegetation. You don’t want to poison expensive landscaping nearby.

How Often do I Apply The Copper Solution?

You’re going to have to periodically re-apply the copper sulfate solution because normal rainwater will leach the copper back out of the pavers. I can’t tell you how often because it’s a function of the amount of rainfall where you live. But I do know it’s far easier to apply this solution in minutes rather than bend over for hours and hours using a power washer!

Column 1215


How To Get Rid Of Moss From Paver Patios + Driveways + Walkways {Guide + Tips}


Most folks living in Southern California do not have a lot of issues with moss growing on their property, but it does happen. Even in areas with warm, dry climates — like San Diego County and Orange County — there are spots that are prone to moss. These moss-prone areas might be near the coast, in shady spots under trees or in areas with excessive moisture from a leak or overwatering.

If you have moss growing on your paving stone patios, driveway or walkway, it can be both visually unappealing and a slipping or tripping hazard. Unless you happen to be going for a rustic, old-world look, you most likely want to get rid of moss as soon as possible.

There are several ways to remove moss from pavers and other surfaces, including both natural and not-so-natural options. Here are eight moss removal tricks you can use to keep your paving stones looking beautiful. As an added bonus, these tips for getting rid of moss can also be used on rocks, concrete and bricks.

Here are 8 tips to get rid of moss…

Remove Moss Tip #1: Sunlight

The easiest, least expensive and most natural way to get rid of moss is to expose it to sunlight. Move cars and patio furniture, prune nearby trees and shrubs, and let the sunshine in to directly shine on the mold. Moss does not grow in sun-soaked, dry areas, so this may be the only solution you need.

Remove Moss Tip #2: Repair Leaks and Adjust Irrigation

If your moss is caused by a leaky faucet, broken pipe or errant sprinkler heads, make the necessary repairs and adjustments to stop the collection of moisture in the area. This will also put you back in line with San Diego’s and California’s mandatory restrictions for water use, which include immediately repairing leaks and avoiding runoff.

Remove Moss Tip #3: Boiling Water

Much like weeds growing in driveway cracks, the moss on your paving stone walkway or patio can be tamed by pouring boiling water over it. This is another natural option that will have little to no effect on desirable plants nearby. You will likely need to follow up the boiling water bath with a good scrub with a deck brush or a stiff broom.

Remove Moss Tip #4: Vinegar

Vinegar is a popular choice for naturally getting rid of unwanted weeds and an also be used to kill moss. When using this natural option, you may find that you need to treat the area multiple times to achieve the desired result. You may also find that vinegar is just not strong enough to fix your moss issue, but it is a good option to try before moving to chemical-based solutions.

To treat your moss with vinegar, mix equal parts vinegar and water in a spray bottle. Saturate the area well, while being careful to not get the vinegar on the leaves of desirable plants near the treatment area. Allow the mixture to work into the paving stones and joints for at least 15 minutes, and then use a deck brush or stiff push broom to scrub the area. You can follow this with hosing the area down with water, if needed.

Remove Moss Tip #5: Power Washing

Another natural option is to use a power washer to get rid of paving stone moss. This method may or not be effective in ridding you of your moss problem and uses a lot of water, so this should not be the first option you try. If you do opt for power washing, you may need to replace joint sand between your pavers if it is washed away in the process. Cleaning and sealing your pavers is a great way to remove moss and restore the original appearance of your paving stones.

Remove Moss Tip #6: Baking Soda

Baking soda is another natural option that is good to try before moving to chemical means, but may or may not be effective enough on its own. This partly depends on how serious your moss issue is at the time of treatment.

To use baking soda to remove the moss from your paving stone driveway, walkway or patio, sprinkle it generously over the moss. Leave it overnight, and then use a push broom or deck brush to first remove the baking soda, and then to scrub the area to remove the moss.

Remove Moss Tip #7: Bleach

As we move away from natural options and into stronger solutions, bleach is one that you can try. If you choose to use bleach to remove moss, be sure to keep children and pets away from the treatment area during and immediately after you treat it. You will also want to be careful not to get bleach on desirable plants and to be very careful when rinsing the area to avoid bleach running off into other areas.

It is best to scrub the area with a deck brush or stiff broom before applying your bleach solution. You can then mix equal parts bleach and water in a spray bottle or larger sprayer and treat the area. Leave the bleach solution on the area for at least 15 minutes, and then scrub the area again and rinse with water. Whether you use the bleach from your laundry room or a moss-killing bleach you can buy at your local home improvement store or garden center, be sure to wear protective eyewear and gloves when working with bleach.

Remove Moss Tip #8: Commercial Moss Killers

When all else fails, it may be time to bring out the bigger guns, which, in this case, are commercial moss killers specifically designed to get rid of moss. There are many options available, including some that are known carcinogens and respiratory irritants. According to Alternatives: A Washington Toxics Coalition Fact Sheet published by the Washington Toxics Coalition, here are a few of the least-toxic, commercial moss killers available:

  • Safer Moss & Algae Killer and Surface Cleaner II
  • Bayer Advanced 2-in-1 Moss & Algae Killer
  • Worry Free Moss & Algae Control
  • St. Gabriel Laboratories Moss Killer

Install-It-Direct Can Help

If you have questions or need additional tips for keeping your paving stones moss free, give us a call. You can also join our mailing list to receive landscaping ideas, yard care guides, outdoor entertaining tips and more.

Raymond Evison has been fascinated with clematis for more than 50 years, and he believes there is still more work to be done with the plant.

He raised his first new clematis cultivar when he was 18 years old. He named it Edith, after his mother. Now 70, the legendary British breeder is showing no signs of slowing. Over the summer, he won his 26th gold medal at the Royal Horticulture Society’s annual Chelsea Flower Show, and visited several U.S. garden centers on a mission to help retailers better understand the flowering clematis with the distinctive blue label.

“I believe we offer some of the best new clematis that come to market,” he says. “So, we’re really there to hold our customers’ and our customers’ customers’ hands to make sure they do a good job on the retailing.”

The business of breeding

Evison’s breeding really took off in 1992, when he formed a joint venture with the Poulsen Rosa Company from Denmark. Poulsen Rosa was known for rose breeding, and Evison hoped to leverage that knowledge, as well as the company’s experience with plant patenting, with his knowledge of clematis.

“We decided that we wanted to produce more compact clematis, because we knew people would be using smaller gardens,” he says. “We wanted clematis that were more free-flowering and producing more flowers, and were much more compact in their habit.”

Serious clematis breeding started in the early- to mid-1800s. Despite growing to eight- or nine-feet tall, many of the varieties from that era have just one, single large flower at the end of a growing stem. There were about 500 cultivars listed by the beginning of the 20th century, Evison says. Many of those have been lost, but Evison still grows about 50 of them.

“We then listed up 10 to 15 criteria that we wanted our mother plants to have,” he says. “Many of the ones that we actually used in that early breeding program were cultivars from the early 1800s.”

As part of the joint venture, Evison licensed growers around the world to propagate his plants under the brand name Raymond Evison Clematis. Of course, Evison’s own Guernsey Clematis Nursery is one of the licensees. Located on 8½ acres in Guernsey, a small island in the English Channel, the nursery produces about three million clematis plants annually and has about 90 employees during peak times. Evison estimates that his nursery produces about 20 percent of the world market for young clematis plants.

Select North American growers that are licensed to grow Raymond Evison brand clematis receive a few cultivars every year to add to their range.

After the nurseries have grown the plants for two years, they sell them to retailers. If those garden centers participate in the Evison-branded plant program, then they are listed on the brand’s website. Evison has about 800 garden centers in North America and the U.K. that are brand retailers.

Though this is the last year of Evison and Poulsen’s arrangement, Evison’s breeding will continue.

“They wanted to do other things, so we haven’t fallen out or anything like that,” he says.

When Evison and Poulsen had their program running at full-speed as it were, they would do about 2,500 crosses a year. That would generate 35,000-40,000 seeds, which would generate about 10,000 seedlings. After a four- to five-year evaluation and selection process, only five or six of those seedlings make it to market. It takes about 10 years from the time of pollination to actually putting a new clematis on the market.

“The breeding work that my team and I are doing this year, I’m going to be 80 before those are on the market,” Evison says. “I think the consumer thinks these things happen overnight, but we really need to do the evaluation process and be certain that the plants don’t succumb to mildew. We’re very rigorous with our selection work.”

Before Evison sends a plant to market, its strength and constitution is tested. It won’t succumb to mildew unless it is placed in ideal conditions for breeding mildew.

“With the very rigorous selection process, anything – even if it’s a fantastic color break in the plant – and the plant doesn’t have a good constitution, then I’m afraid it gets thrown away in the skip,” he says.

Clematis wilt also affec ts clematis in gardens, but Evison says he hasn’t seen that in his nursery for many years.

Breeding a better clematis

Evison’s clematis selection process is very detailed. The first evaluation is during a one-year period. New cultivars are selected in the spring. In the summer, the plants are cut down and then re-flowered. Then, they are examined again in mid-summer to early autumn. Evison says that seeing the plant at different times of the year is important.

Evison looks for plants that are “free-flowering.” In the context of clematis, that means they will produce a lot of flowers up along their stems. The older clematis cultivars have a stem, a stalk, and one flower at the top. Some of the cultivars Evison has developed have five, six or even seven leaf axle nodes that produce flowering buds, as well. And those flowering buds produce second flowering buds. That trait is valuable in a clematis, and that is one area Evison focuses on in selection.

Color is another important factor. Evison aims for colors that don’t fade, unless that fade creates an attractive, eye-catching look.

“We’re certainly looking for different colors, color breaks, and we’re looking for really strong colors,” he says. “There’s also a market for the pale pinks and the whites. We also look for if the flower has a good shape. Maybe the shape is very, very different, so we’re not always looking for round-shaped flowers or things that have pointed sepals, but we’re looking for a plant that will say to the consumer, ‘Pick me up and buy me.’”

Evison also has focused on breeding and developing more fully double-flowered clematis because of how much those resonate with the consumer.

The North American market has been challenging for clematis breeders because of the severe winters in much of the country. There’s a lot of winter kill with the single large-flowered clematis in that market, and all the top rows get killed down to ground level. Many of the older varieties of double clematis raised in the 1800s and early 1900s will not produce any double flowers after winter kill, because the double or the semi-double flowers come from the previous season’s ripened stems. This is a problem that Evison has been working to solve.

“The advantage of our clematis is that even if they are early flowering and even if it has been a severe winter, they will flower still quite early on in the season. If you had an old fashioned ‘Nelly Moser’ – they’re still a good clematis – and they got killed down to ground level, you probably wouldn’t see any flowers until about August or so. Our new varieties we’ve selected flower very profusely on the old wood or the new growth.”

Evison’s most popular cultivar is clematis ‘Rebecca.’ Named after his eldest daughter, its calling card is its dramatic, large red flowers.

One cultivar that stateside growers should watch for is clematis ‘Samaritan Jo.’ It is new for 2014 in the U.S. It has a silvery-pink center and darker purple coloring on its edges. Evison says it’s very free flowering and ideal for growing up into roses. It also works well in containers. ‘Parisienne’ is another cultivar that excels in containers due to its compact nature. It boasts violet flowers with a dark red center, and has been one of Evison’s best sellers since its introduction in 2005.

Evison has even worked with British royalty on some of his cultivars. “If you have a shady deck or patio, then ‘The Countess of Wessex’ is very good,” Evison says. “We launched that with the countess in Chelsea in 2012.”

A misunderstood plant

Evison breaks down his new cultivars into several groups. The Regal collection are double-flowered clematis that can be grown in pots and containers or walls or trellises. The Boulevard collection is made up of compact plants that are ideal for smaller pots and gardens.

“You don’t have to have a six-foot wall to grow clematis,” Evison says. “I’m very keen that clematis are grown with other plant material and not just on a plain trellis.”

In fact, Evison’s most recent book, “Clematis for Small Spaces,” details 150 of the best clematis cultivars for patios and balconies. He wants to make sure today’s consumers are educated about the plant, which he says is often misunderstood.

“They’ve read in books or magazines what complicated plants they are,” Evison says. “This is one thing that I would like to stress from our breeding point of view and particularly from the garden center point of view. With our new clematis – the Evison-Poulson clematis – for the singles and the doubles quite simply, reduce their top growth by one-third every spring. That’s at the end of winter just before bud break. With all of our other single ones, we’ve simply introduced a technique called ‘the ponytail cut.’ You grab the growth and you chop it off 6 to 9 inches above soil level. That can apply to all varieties that are not double or semi-double. That, again, you do in the winter or early spring. It’s really simple. People haven’t got to get their reference books out knowing what bit to cut out and what bit to leave and all the rest of it. As we’ve developed these clematis, you can be pretty ruthless. Chop off the top growth and away they grow and flower.”

In the future, Evison wants to breed cultivars with improved cold hardiness. He’s working with the idea of producing more fibrous roots that could withstand colder winters without needing to take the plant indoors.

Every little improvement he makes demonstrates the value of breeding. He believes growers and consumers shouldn’t shy away from paying more for the better mildew tolerance, double flowering, and easier pruning available with his branded clematis.

“Nurserymen and the consumer should not be thinking purely about price,” Evison says. “They should be thinking of the quality of the plants. Sometimes people will say, ‘I don’t want to buy that. It’s got a royalty on it. It’s too expensive.’ I think the consumer and the nursery industry need to consider that a lot of time goes into the breeding and developing of new plants. That has to be rewarded with royalty collection. Some of the old varieties are still very, very good, but they do not perform in the way that our new ones perform.”

For more:

Long story short, not very well. There have been many studies done on how to stop them from growing, but the results are short-lived. Prevention is key in control. Regulating the population is important so that greenhouses don’t have to expend more resources and money on using more water and fertilizers. Post-emergence herbicides have been shown to control 100% of liverwort populations, however the control did not extend to the spores.
The following are ways to prevent liverwort populations from forming:
-Cover containers to prevent light from entering their habitat
-Cover potting mixes to prevent spores from entering before potting, and sanitize all containers that are to be used.
-Apply fertilizer to media before potting, and make sure to carefully monitor nitrogen, as liverworts’ growth is highly dependent on it.
-If herbicide is used outside of a greenhouse, pre-emergent treatments have been shown to be most effective, such as flumioxazin. Flumioxazin* is used for both pre and post-emergence, and is not registered for use inside a greenhouse
-Use irrigation techniques that minimize putting water on the top of containers, where liverworts will intercept the water from plants.
-Cuttings taken from liverwort infested containers can carry viable spores with them
-Baking soda will kill liverwort plants, but that doesn’t mean it kills the spores. A commericial herbicide called TerraCyte* (sodium carbonate peroxyhydrate) is useful against post-emergence and is registered for use in greenhouses.
There are few herbicides registered specifically for liverworts, but there has yet to be discovered a solid way to permanently treat these plants without harming the nursery plant as well. Some herbicides kill liverworts but it is only temporary. The spores are very difficult to control. As stated above, pre-emergence control is the best way to get a step up on liverworts.
*Any herbicides mentioned in this article were for informational use only and are not sponsored by the author.

Jeyes Fluid 5L

Jeyes Fluid 5 Litre

Jeyes Fluid is universally acknowledged to be one of the most flexible commodities available to everyone involved in horticulture. Its success is based upon its ability to be used for an amazing variety of tasks; from cleaning bird feeders – to ensure that they remain free of trichomonosis and Avian Flu – to hygienically freshening up garden furniture.
Jeyes fluid is also used to disinfect tarmac, hard surfaces, patios and driveways supporting mould and algae, and is great in combination with a pressure washer.
Its universal suitability means that Jeyes Fluid can be safely used in many common garden situations i.e. cleaning out water butts, ridding greenhouses of the variety of diseases that become a genuine problem during the growing season, or simply cleaning drains. Jeyes Fluid can also be used to disinfect areas after livestock and animals.
As a disinfectant, Jeyes Fluid has been a familiar site in many gardens and allotments since 1877, when it was bought to us by the same company that created other trusted and familiar brands such as Palmolive, Carex, Imperial Leather, and Ajax.

Application Instructions

Cleaning and Disinfecting Drains:
Pour neat into outdoor drains, making sure to rinse thoroughly.
Use as frequent as necessary, especially during hot spells.
Concrete Paths and Patios:
Dilute 150ml Jeyes Fluid to every 5 litres of water, applying sufficient solution to thoroughly wet the affected surfaces. Allow 30 minutes for Jeyes Fluid to work and then rinse off with water and scrub with brush. For light coloured aggregate, dilute 50ml product with 5 litres of water, in order to avoid staining.
Tarmacked Areas:
Dilute 125ml Jeyes Fluid to 5 litres of water in a watering can, then apply sufficient solution to thoroughly wet the affected surfaces. Firstly, make sure to check a small area for softening. If the tarmacked area softens, use a lower dilution of 60ml product to 5 litres of water and repeat treatment 1 month later.
Canes, Secateurs, Knives & Various Other Outdoor Tools:
Wipe the tool over with a solution of 10ml Jeyes Fluid per litre of water. Next, leave for 5 minutes before rinsing off.
Cleaning Out Water Butts:
In order to clean water butts, scrub with a solution of 15ml product to 5 litres of water. To freshen water, add 5ml Jeyes Fluid to a full water butt.
Disinfecting and Cleaning Greenhouses:
First, remove all plants then wash down all glass, glazing bars and shelving with 35ml Jeyes Fluid per 5 litres of water. Make sure to ventilate and allow greenhouse to dry before reintroducing your plants.
Avian Influenza/Bird Flu:
Use a solution of 250ml Jeyes Fluid mixed with 5 litres of water to disinfect surfaces against Avian Influenza. Remove any excess soil, and apply the product via a watering can, allowing at least 20 minutes contact time. Finally, rinse off after use.
For further information regarding Jeyes Fluid 5L, please contact our technical sales team on 01902 440250.

Moss Clear Pro – Fast Acting Moss, Algae & Mould Remover

Powerful Moss Killer for Driveways, Patios and Roofs

Concentrated moss killer to kill moss, green algae, fungi, mould, mildew and lichen on external hard surfaces.

MOSS CLEAR PRO is a highly effective microbiological biocide that will break down and kill moss quickly. It will also swiftly erase and prevent regrowth of mould, algae and mildew which are potential health hazards.


  • Apply to dry surface by watering can or sprayer in temps between 8-20° degrees
  • Do not spray if rain is expected within 24hrs of application
  • Application ratios 1:10 or 1:5 for areas of heavy contamination
  • As a preventative, use at approx 1:20 ratio applying once or twice yearly
  • Coverage of 100m² can be expected from 5 litres, when diluted 1:5

Moss Clear Pro works as a moss killer and moss remover on most external surfaces such as driveways, patios and roofs. Regarded by professionals as the best moss killer for tarmac and asphalt driveways. It is a stronger formulation that Moss Clear which is frequently used by homeowners for DIY purposes.
It is a a very effective roof moss remover and used extensively for roof cleaning throughout the UK and Ireland. Can also be used as a moss inhibitor to prevent moss growth on roofs, driveways and patios.

How to Remove Moss from Tarmac

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Removing moss formations from tarmacs is an easy job when you understand how the plant grows, and the different conditions that make it thrive. In this short article, we will share the different steps that you can follow to eradicate moss growths.

How Moss Grows

Moss is a plant that grows on damp and shaded areas, appearing like a thin green-colored overlay. These plants reproduce through spores and can easily spread through the air or water. Moss has a tendency to steal nutrients from other plants. This is why you seldom see other plants growing near areas infested with moss.

They thrive best on moisture-rich areas like waterlogged pathways, tree trunks, pavements, walls, etc. If you have a tarmac-paved driveway that is shaded from the sun and is frequently exposed to rain water, moss is bound to form along the tarmac’s surface.

To eradicate and prevent future moss formations, you need to make sure that your tarmac is not exposed to the different conditions that make moss formations thrive (i.e. moisture-filled environment). On tarmac drives, moss growth is unavoidable due to its surface component. A tarmac can easily be broken down after continued exposure to the elements, and this presents an opportunity for moss to form.

Things You Will Need

Depending on your specific needs, you may or may not use all the tools listed below. Assess your needs and adjust accordingly.

  • Shovel
  • Commercial Moss-Killing solution like Baticlean, MMC Pro, Qualgex, or
  • Homemade solution of water, bleach, and detergent
  • Stiff bristle brush
  • Pressure washer or hose
  • Saw or garden shears (for trimming tree branches or shrubs)

Steps to Remove Moss Formations on a Tarmac

Before proceeding, note that the steps outlined below are specifically tailored for removing moss from tarmacs. Some steps may not apply to you if the moss growths you intended to eradicate are not growing on tarmacs.

  1. First, you need to assess the level of moss growth on your tarmac. Look into the degree of moss infestation: the thickness of the moss growth, area covered, water source.
  2. Next, also assess the level of shade/sunlight that your tarmac pathway is exposed to.
  3. Cut overarching tree limbs or trim shrubs that are located near your tarmac driveway or pathway. This allows ample sunlight to reach the tarmac during sunny days and vaporize any water formation on the tarmac surface. Note: If cutting away the trees around or near the tarmac is not an option, you should proceed to the next few steps for more permanent ways to remove moss growth.
  4. Remove any plants growing near the tarmac that you intend to tear with moss-killing solutions as they may damage existing foliage.
  5. Clean up the tarmac’s surface and remove any garbage.
  6. Then, if you want to readily remove the unsightly green moss from the tarmac, it’s best to shovel out the mossy layer first; use a stiff stipple brush. And then apply the moss-killing solution.
  7. But if you do not prefer to shovel the mossy layer, you may begin spreading the moss-killing solutions right away over the moss layers using a pressure washer or hose.
  8. After doing either steps 6 and 7, make sure that the tarmac is exposed to the moss-killing solution for the next few days.
  9. It is important to select a sunny week when doing this moss eradication routine. This ensures that your moss-killing solution is not washed away in the rain.
  10. If the tarmac has been exposed to moss for a long time, you may need to repeat the process two or three more times.
  11. Once the tarmac has been fully exposed to the moss killer solution, after a day or two, you may apply a less concentrated layer of moss killer solution. This step ensures that no old moss spores survive.
  12. If your tarmac has an uneven surface or other areas that have holes, make sure to fill them up with gravel or new tarmac. This ensures that your tarmac does not trap water and prevent nurturing conditions where new moss can grow.
  13. After doing these steps, you can rest easy, knowing that your tarmac drive is now safe from moss growth.
  14. Remember that moss may regrow if the old conditions (shade and moisture) that facilitate their growth occur again or if new moss spores travel to your tarmac. To prevent this, you may start a yearly preventive moss-killing spree for your tarmac drive.

Armed with ample knowledge of effective moss eradication, cleaning up your own tarmac drive will be easy. Yet, if you do not have the time to do it, you may always hire the services of weed eradication companies or you can delegate the task to a gardener or family member. There is no reason for you to put up with a mossy tarmac when the steps to making it immaculately clean again is relatively easy.

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