- Stay Up-to-date with the di Stefano Landscaping Team
- Perennials To Cut Back In The Fall
- Perennials To Leave Up Through The Winter
- Q: How much of the plant should you cut back?
- Q: Why should you cut back perennials?
- Q: So, cut back all perennials in the fall?
- Q: How should you deal with diseased plants or infestations?
- Q: When is the best time to cut back in the fall?
- Growing daisies: all you need to know
- How To Prune Geranium Plants
- Steps for Pruning Geraniums
- Here’s our Seasonal Guide to Pruning Geraniums:
- Blue corn flowers… Cutting back after blooms
- The Genus of Centaurea
- Centaurea Species’ Growing Habit
- Centaurea Varieties
- Perennial Cornflower’s Medicinal Properties
- Planting your Centaurea
- Caring for your Cornflowers
- Pests and Diseases
- Good Border Companion Plants
- Three reasons to cut back perennials after flowering
Stay Up-to-date with the di Stefano Landscaping Team
In late fall, once all of your perennials have started to turn brown and die back, it’s time to prune some and leave some to cut back in spring. It’s common to think that everything should be chopped down to the ground in the fall, but some perennials actually need their foliage to protect new shoots through the winter. Other varieties offer up important habitat for local wildlife and some perennials provide height and interest through the winter months. We’ll go over a sampling of common perennials here in Vermont and list when to cut them back (and why).
Perennials To Cut Back In The Fall
There are a variety of perennials that should be cut back in the fall. Prune foliage down to just a few inches from the ground and make sure to clear away any debris from the garden to help prevent disease and rot in the early spring.
If perennials (like Bee Balm or Phlox) were diseased this past season, cut the foliage all the way down to the ground and don’t compost it. Throw it away or dispose of it in an area far enough away from the garden that other plants won’t be subject to the disease. Make sure to clean your pruners with a mixture of bleach and water after dealing with any diseased plants.
Plants To Cut Back In Fall:
- Bearded Iris
- Bee Balm (Monarda)
- Gaillardia (Blanket Flower)
- Catmint (Nepeta)
- Columbine (Aquilegia)
- Daylily (Hemerocallis)
- Peony (Paeonia)
- Solomon’s Seal (Polygonatum odoratum)
- Yarrow (Achillea)
Perennials To Leave Up Through The Winter
There are several common perennials that should be left up throughout the winter for a variety of reasons, including protection, adding winter interest, and helping local wildlife.
Plants to Cut Back In Spring:
- Annual wildflowers. If you planted annual wildflowers like Cosmos, Zinnias, or Sunflowers, leaving them up through the winter helps them to drop their seeds and come back the next year. If you can’t stand leaving them up (or are part of an HOA that makes you cut them back), cut them back and leave the debris on the ground. This should help them drop some seeds for the next season.
- Echinacea (Coneflower) and Rudbeckia (Black Eyed Susan) should be left up until spring to attract and feed birds throughout the winter.
- Sedum and Ornamental Grasses should be left throughout the winter to add height and interest.
- Butterfly Weed (Asclepias), Ferns, and Heuchera (Coral Bells) should be left until spring because the foliage helps protect their crowns.
Hydrangea is an illusive shrub that can be pruned in the late winter/early spring or just after they’ve finished blooming, depending on the variety. Hydrangeas that bloom on old growth (like “Endless Summer”) should be pruned immediately after they’ve finished flowering. Hydrangeas that bloom on new growth (like the popular “Annabelle” and “Limelight”) should be pruned in the late winter or early spring. This is why it’s always good to save plant tags or write down which varieties you have in your garden!
Fall cleanup can sometimes seem daunting, but with all of the right information at your fingertips it can be done in just a few short hours.
Don’t have time for fall (or spring) cleanup? Contact us to get on our schedule!
The notion of putting a garden to bed for the winter really resonates me. I’m not someone who has sleep issues, but the quality of my slumber is hugely affected by whether I’ve adequately prepared for bedtime. On the nights I’m able to follow through on my normal routine—brush teeth, shower, put on crisp cotton pjs, and, most important, slip into a well-made bed—I find I have a far more serene night’s rest than had I just stumbled into bed without any preparation.
So I get that it’s important to give your garden a good foundation for its wintertime hibernation—to clean it up a bit, weed one last time, protect delicate new plants, and cut back perennials. I really do. So what’s stopped me from doing it? The last part. Which plants exactly need to be cut back? Why? And how? I asked San Francisco-based garden designer Sarah Madeline Stuckey Coates for advice on cutting back perennials in the autumn.
Featured photograph by Christin Geall, from Flower Design: A Week at the Cambo Estate in Scotland.
Above: Ornamental grasses are one group of perennials that shouldn’t be cut back till late winter or early spring, as they provide continued visual interest during the colder months. Photograph via Hummelo: A Journey Through a Plantsman’s Life.
Q: How much of the plant should you cut back?
A: Sarah says there are two types of pruning: “ongoing light pruning (also known as deadheading), multiple times a year when you shear off the spent blooms before they go to seed, and an annual ‘hard prune’ when you cut the plant all the way down to the ground or severely reduce it once or twice a year so the plant looks fresh and clean when the new foliage emerges.” When gardeners talk about cutting back in the fall, they’re talking about a hard prune.
Q: Why should you cut back perennials?
A: “The short answer is the aesthetics and health of all perennial grasses and flowering plants benefit from being cut back,” says Sarah. On the aesthetics front, “perennials are often reinvigorated and perform and look better when they get cut back. The plant naturally dies back annually when it goes dormant, and you want to remove the unsightly material so that when the spring emergence happens, the new foliage comes up all fresh with no scraggly, dead stuff marring its beauty.” On the health front, getting rid of dead or dying foliage on plants discourages fungal growth, disease, and infestations. Another reason for cutting back: “Keeping plants in their lane,” says Sarah. “Prune to keep plants from overtaking other plants. If you have a more wild, Monet type garden, you’ve planted a bunch of different species in drifts that blend together. If one of them is being thuggish and taking over another, prune it away so the less aggressive plant can shine and play it’s role in the garden, too.”
Q: So, cut back all perennials in the fall?
Above: Many seedheads provide food to wildlife and are worth keeping around through winter. Photograph by Marie Viljoen, from Putting a Garden to Bed: My Autumn Check List.
A: This is the tricky part. Some perennials should be left alone till spring to prune; for instance, hostas, asters, and heucheras need their foliage for protection over the winter. “And many plants look fascinating and gorgeous in their winter dormant form,” she notes, not to mention passing birds and beneficial insects “may depend on the dried flowers, fruit, seed pods, and foliage for sustenance or habitat.” Unfortunately, there is no easy way to figure out which plants are best cut back in the fall and which are best cut back in the spring (though, in general, leave woody plants like lavender and Russian sage for the spring). Here are some popular perennials that fare well with a fall cutback: bearded iris, columbine, salvia, yarrow, peonies, and day lilies.
Q: How should you deal with diseased plants or infestations?
A: “Any outbreaks of the various maladies can not only kill your perennial, they also can spread to others,” she warns. “Look closely because sometimes the culprits are quite small or on the underside of the leaves. Remove the infested parts, dispose of thoughtfully by keeping them contained so they don’t spread and put them in the trash rather than the compost.” Last, clean your pruners after each use with isopropyl alcohol or a bleach-water solution (with a 1:9 ratio of bleach to water).
Q: When is the best time to cut back in the fall?
A: “When they start to look too ratty for you and before the fresh new growth begins,” says Sarah. For plants that are frost-sensitive, wait until after the plants have gone through several hard frosts to ensure they’re dormant before cutting back.
For more on putting your garden to bed, see Putting a Garden to Bed: My Autumn Check List and Expert Advice: 7 Tips to Put Your Garden to Bed for the Winter.
For more Your First Garden posts, see:
- Your First Garden: What You Need to Know Before You Plant a Tree or Shrub
- Your First Garden: What You Need to Do in Fall for a Lush Lawn in Spring
- Your First Garden: What You Need to Know Before You Plant Bulbs
The sun has been going down earlier and nights have been getting colder, making it feel like fall. As all the golds, reds and browns start to take over, the greens fade away. The late blossoms in your garden will wilt, signaling the end of the growing season.
The end of the season means the vegetable garden needs to be cleaned up, the annuals need to be pulled after the first frost and the perennials need some grooming when they’re done blooming. Tending to the vegetable garden is pretty simple — toss the plant debris in the compost pile. Pulling annuals is easy as well — toss the plant debris in the compost pile. Perennials are a little trickier.
Which perennials need cut back?
Gardeners have more time for cleanup in the fall when they are unburdened by planting season. However, many rush outside and make the mistake of cutting their plants back too early. Unless they are diseased or infected, it’s better to wait until several frosts have killed back the tops before cutting plants back. This gives their roots time to reclaim energy from the dying portion to store for new growth in the spring. In some cases, leaving plant tops over winter is preferable.
Diseased or infested plants. Plants plagued by disease or riddled with insects need to be cut back right away to reduce the chance of infection the following season. After removing the damaged stems and leaves, destroy the debris rather than composting to avoid reintroducing the disease or pest in the spring.
Hostas. Hosta leaves need to be removed as soon as they are damaged by frost, as dead leaves harbor slug eggs. If left alone, the leaves could become infested, ruining next year’s garden when the eggs hatch.
Plants with browning or blackened foliage and bare stalks. It saves time in the spring to cut back plants that don’t add anything visually to your winter garden and serve no purpose for wildlife through the winter. Some examples include peonies, daylilies, brunnera and speedwell.
Cutting back perennials
We cut back perennials in the fall to clean our gardens up for spring, encouraging new growth and flowering. When pruning your plants, follow these guidelines:
- Make clean cuts through plant stems during the pruning process. Bypass pruners are preferred, but hedge shears are also acceptable to use.
- When cutting back plants, leave two inches of stem above the soil. This is to both mark the location of late-blooming plants in the spring and ensure optimum regrowth.
- Don’t mix insect infested or diseased plant debris in with healthy debris. Healthy debris can be composted or left around your perennials until spring, while diseased and infected plant stems and leaves need to be discarded.
Perennials to leave standing
While some plants require maintenance in the fall, others are better left alone to overwinter more successfully, add to your winter landscape, provide food for birds and shelter beneficial insects.
Add to the landscape. Alongside evergreens and the skeletons of shrubs, ornamental grasses and standing perennial seedpods can add dimension to your winter garden. You can leave them standing through the winter and cut them back in the spring before new shoots appear. Some examples of grasses to leave standing are switch grass, zebra grass and feather reed grass. Some examples of plants with interesting seed pods include Siberian iris, blue false indigo, sedum ‘Autumn Joy’ and Joe Pye weed.
Provide food for birds. Many birds rely on the seed heads of dried perennials for food and find protection from the weather in plant stubs and ground covers. Some favorite food sources include purple cornflower, black-eyed Susan and oxeye sunflower seeds.
Shelter insects. Beneficial insects rely on native plants to hide in for winter as pupae, caterpillars or eggs. Plants and plant debris provide shelter from insect predators, as well as winter weather.
Marginally hardy perennials. Leave marginally hardy perennials standing. They are more likely to survive winter if their tops are left to collect leaves and snow for insulation and moisture. Some examples include mums, anise hyssop, red-hot poker and Montauk daisy.
Evergreens. Low-growing evergreen and semi-evergreen perennials can be left alone in the fall and cleaned up in the spring. Some examples include hardy geraniums, heucheras, hellebores, dianthus and moss phlox.
- Penn State University
STAY INFORMED. SIGN UP!
Up-to-date agriculture news in your inbox!
Growing daisies: all you need to know
Last updated on 14 October 2019
Daisies are a gardener’s best friend as they’re cheerful and very easy to grow
RELATED TO GROWING DAISIES: Growing orchids
Rivalled only by orchids, the daisy family is the largest group of flowering plants on the planet with 23 000 currently accepted species, spread across 1 620 genera. These toughies are found in areas ranging from the Polar Regions to the tropics, carving out a niche for themselves in practically every habitat. Although most daisies warrant a place in the garden, these are our five favourites.
SHASTA DAISIES (LEUCANTHEMUM × SUPERBUM)
No matter what your level of gardening proficiency is, Shasta daisies bring waves of cool white blooms to the garden from late spring right into autumn.
Plant them in any sunny spot in well-drained, compost-enriched soil. They’ll tolerate a little shade, but tend to become ‘leggy’ with not enough direct sun.
Growing tips: Keep on deadheading spent blooms to encourage a season-long show. The whole plant can be cut right down in late winter. After the third year or so you can divide up the clumps to keep your plants vigorous and flowering at their best. To do this, dig the plant up in late autumn and using a sharp spade, divide it two or more pieces, which can then be replanted or shared with friends.
YOU’LL ALSO LOVE: Growing sunflowers
MICHAELMAS DAISIES (ASTER NOVI-BELGII)
Just when your summer garden begins to fade these asters will bloom with an abundance of sumptuous flower heads. Single and double varieties are available in shades of purple, violet, blue, pink, reddish-pink and pure white.
Plant them in full sun or semi-shade; the hybrids vary in height from about 30cm to just over 1m high. They prefer sandy soils enriched with compost, but will perform in clay soils as long as the beds are prepared well beforehand. Asters are excellent in borders, mass plantings and pots; don’t forget to pick some for the vase.
Growing tips: Divide the clumps every few years, refreshing the soil to keep your plants healthy.
READ MORE: 7 Shrubs ideal for small gardens
GOLDEN DAISY BUSH (EURYOPS PECTINATUS)
This shrub grows up to 1,5m high and sports attractive grey-green foliage; its golden yellow blooms are borne nearly all year round with the main display in spring.
Plant it in full sun and in well-drained soil, where it will be both fast growing and free flowering. It makes an excellent shrub for the border and looks lovely as part of a mixed perennial backdrop.
Growing tips: It needs a moderate amount of water, but in summer rainfall areas requires a weekly watering throughout the winter months. Your bushes will respond well to pruning and should be cut back hard every few years.
YOU’LL ALSO LOVE: Add floral touches to your home this summer
FELICIA DAISIES (FELICIA AMELLOIDES)
Felicia or Kingfisher daisies are endemic to the coastal areas of the Eastern and Western Cape; you’ll spot their blue blooms just about all year round on bushes growing on sand dunes or stony outcrops. Some varieties have variegated leaves.
Plant them in well-drained soil in a bed that gets loads of sun. Once established, felicias are quick growing and will look good for many years.
Growing tips: After planting, pinch back the main shoots to encourage bushing. Deadheading will extend the flowering season. After a few years they may start to look a little straggly, but this is soon remedied by a severe haircut. Felicias will survive light frost by simply re-sprouting and possibly flowering a little later than usual. While most pests don’t bother felicias, the same can’t be said for butterflies who adore their blooms.
READ MORE: Homemade pesticides
MARGUERITE DAISIES (ARGYRANTHEMUM FRUTESCENS)
Marguerite daisies come in a variety of colours and bloom for most of the year in mild climates. They thrive in autumn and early spring when they look their best.
Plant them in a sunny spot; they do particularly well in coastal regions. Prepare the soil with plenty of rich compost, making sure it’s loose and drains well. These plants can grow up to 1m high with a similar spread so space them accordingly.
Growing tips: Once new plants are actively growing, pinch them back to the fifth or sixth set of leaves to promote a good shape. Keep them well watered as drought will cause dieback. Conversely, overwatering can cause the plant to collapse.
Marguerite daisies are considered hardy to -1°C. In warm areas, they’ll stop blooming if night-time temperatures stay above 20°C. If this happens, trim them back with a sharp pair of scissors to force them to branch out and develop new growth. When the night-time temperatures fall, the plant will bloom again.
Pruning For a Better Garden
How do I prune my garden?
The first question to ask is whether you need to prune your plant at all. There are several situations where pruning is desirable and you should be very clear about what you are trying to achieve before grabbing the secateurs. You may be trying to limit the size of a plant that is growing too big for its position, encourage a more dense habit, increase the number of flowers for next season, repair a plant that has been damaged in a storm or renovate an old lemon tree that is not bearing much fruit. We will look at various pruning techniques below to give you a clear idea of which one you need for a given situation.
A good general rule with flowering shrubs and trees is to prune them straight after flowering because most woody plants start a spurt of growth straight after the flowering period. If left unpruned they will simply continue to add growth onto the flowering stems and this leads to the plants becoming too leggy. As soon as the plant has finished flowering simply trim back the stems a few cm below the spent flowers. At the same time sprinkle a handful of complete slow release fertiliser around the base of the plant and water in well.
This technique is used to make plants branch more so that they have a lot more flowers than if they are left unpruned. Pinch out the rapidly expanding shoot tip/s with your finger and thumb during the growing season as this stimulates the many dormant buds behind the tip to start growing. This in turn eventually leads to many more flowers when those shoots reach the flowering stage later on. The more times you tip prune through the growing season the denser your plant will become, but it is important to stop once flower buds start to form. These can be recognised as they tend to be much more chunky than the slender vegetative shoot tips.
Dead Heading flowering plants
This technique is particularly useful for long-flowering herbaceous plants like marguerite daisies and annuals such as petunias and pansies. Such plants will flower for many months if you keep dead heading them by pinching out with finger and thumb the old flowers as they wither and die. Also be sure to keep them watered and a boost from a suitable liquid feed such as Thrive ® will also help. This process not only improves the appearance of the plant greatly but also directs the energies of the plant into producing more flowers rather than fruits and seeds.
If you have inherited an old garden or simply have a straggly old shrub or tree in the garden then some very hard pruning is an option to rejuvenate it. Certain ornamental trees and shrubs can be pruned back as hard as you like without killing the plant. Examples include azalea, camellia, crepe myrtle, magnolia, bottlebrush, grevillea, melaleuca and many others (check on other species in a reputable garden book if you are in any doubt). Use sharp secateurs or pruning saw to cut the stems back to swellings on the stem that indicate dormant buds and also check that you are cutting any dead material back to healthy tissue (this can be recognised by sappy green tissue beneath the bark).
The resulting growth after renovation pruning is very vigorous and soft and will often not flower very well in the first year after such hard pruning. What it will do, however, is create a framework that should provide a nice bushy flowering plant for years to come.
Pruning tools for the garden
Your pruning task will be much easier if you have the right tools. A sturdy pair of sharp secateurs is a great all-round tool for general work. Pruning shears are ideal for light pruning jobs where the small outer shoots are being trimmed off such as in hedging work. For the big renovation pruning jobs a nice sharp pruning saw will make the job a pleasure rather than a backbreaking chore. For frequent trimming and shaping of plants, powered hedging tools make the job noisy but much quicker. Sharp pruning tools will make a world of difference to the job, and it is worth honing your tools regularly. Small sharpening stones are available from hardware shops, and are easy to use. A pouch to hang on your belt is a great way to avoid the age-old hazard of the lost secateurs.
How To Prune Geranium Plants
Pruning geraniums can keep them looking their best. Cutting back geraniums will prevent woody and leggy geraniums, especially in geraniums that have been overwintered. Below you will find information on how to prune geranium plants to keep them looking healthy.
Steps for Pruning Geraniums
There are three different methods for cutting back geraniums. Which one you use will depend on what you are trying to do.
Pruning Geraniums After Winter Dormancy
If you place your geraniums into dormancy for overwintering or if you live in an area where geraniums die back some over the winter, the best time to prune geraniums is in early spring.
Remove all of the dead and brown leaves from the geranium plant. Next trim away any unhealthy stems. Healthy geranium stems will feel firm if gently squeezed. If you would like a less woody and leggy geranium, cut back the geranium plant by one-third, focusing on stems that have started to turn woody.
Cutting Back Geraniums That are Wintered Alive
If you do not put your geraniums into dormancy for the winter and they stay green in the ground or in containers year round, the best time to prune them is in late fall or just before you bring them indoors, if you plan on bringing them indoors.
Prune the geranium plant back by one-third to one-half, focusing on stems that are woody or leggy.
How to Pinch Geraniums
Pinching geraniums is a type of geranium pruning that forces the plant to grow more compact and bushy. Pinching can be done on new bedding geranium plants that you have just bought or on geraniums that have been overwintered. Geranium pinching starts in spring.
Once a stem on a geranium plant has gotten to be a few inches, using a sharp pair of scissors, or even your fingers, snip or pinch 1/4 to 1/2 inch off the end of the stem. Repeat on all the stems. This will force the geranium to grow two new stems off the original and this is what creates the bushier, fuller plant. You can continue pinching geraniums all through spring, if you would like.
Pruning geraniums is easy and makes your geranium look healthier. Now that you know how to prune geranium plants, you can enjoy your geraniums more.
You love your charming geraniums, we know! But the big question is: when should you prune your geraniums to keep them lush, healthy and blooming?
The good news is that it’s just a matter of understanding the seasons and marking it on your calendar as a reminder. It takes some time and tender, love and care but Geranium Rozanne® is worth it isn’t she? We think so, too.
Update your calendars for reminders each season for your geranium pruning to-dos (and for Geranium Rozanne).
Here’s our Seasonal Guide to Pruning Geraniums:
Spring is a perfect time to plant new, young geraniums for the coming year. Young geraniums during this time of year typically have a few leaves with small flowering buds. There is no need to prune these young plants. Leave them be to become established.
Withy older plants that have overwintered and not pruned in the Autumn cut back all the old dead leaves to the base and watch excitedly as the new leaves start to appear heralding a new season
Rozanne Geranium Tip: As she continues to spread and grow you may wish to trim her edges back away from walkways or high-traffic areas, but generally you can sit back and enjoy her magic.
To keep your geraniums looking neat and tidy, cut off the old flower stems as the blooms finish and the petals drop off.
Geranium Rozanne Tip: She will grow and bloom like wildfire! All you need to do is to continue trimming her back from paths, walkways and other plants.
In most regions you can leave your geraniums in the ground during the Autumn and winter months and then come the following spring, start hard pruning leaving only a few inches of the previous year’s growth above the soil line.
In very cold regions, although Rozanne is a very hardy plant, you should add mulch around her for protection.
Geranium Rozanne Tip: Another option, other than pruning back is to keep her foliage throughout the cooler months that will act as a blanket and cover and protect her through winter.
Blue corn flowers… Cutting back after blooms
My vote would be thus. i am of the impression that there is not a large budget. My favorite kind. i know mosquitos can be an issue up there so, i would get inexpensive screening material and attach tie offs to them, so that they can be rolled up if unwanted. some one should go out and sit there during the time he would be using and see if sun or heat is bothering you. if so, put roll up blinds. Believe it or not we had sliders when we lived in the swamp, 0 shade. We got one of the cheap plastic fake bamboo roll ups – about $20. Hung it up on the eve of the house. In the summer the difference between behind the shade and in front of it was at least 10 degrees and that was only like a 2′ space. If he leaves this down all day during the summer, it will be cooler when he comes home. I have seen no mention of fire feature and it does get cold up there. i do not know about one on the porch, but i could really see one off to the side in front of that large picture window. He could then enjoy it while still warm enough to be out, and also enjoy from inside with little risk of damage. You can buy something or you can make something. If he thinks he is into gardening, he will probably love diy. Anything metal or stone can hold a fire. How about and old metal car bumper. feeders are cheap at farm stores. And how about a 2 for? this depends on the lay out of the house. but if the same side is comfortable year round, using that same side, dig a hole and do this does not have to be this large. place some rocks inside, fill with water, give it a fountain. nowadays you can cheaply do a lighted fountain. then all summer you can see this from that window. After sitting on the porch with a cold drink and your tootsies in the big drink as it were. as winter comes, use the fountain to drain the pool. place your fire feature on the rocks. get out your stool, put your feet up for warm tootsies. i am pretty positive that the other side was for your grill. try Craigs list etc. great place to get cheap used charcoal grills. Can always upgrade if you want. All the other suggestions are great too. I will leave those to you. Planting. I never condone killing anybody unless you know without a doubt, they are worthless. I recommend you dig up and move, try not to destroy the main/tap root. I always use root tone and iomega 3 fish vitamins in my transplants. Plants and trees that size are very expensive to replace. perennials are great. I do very well with things like Roses-no you do not have to worry about them, just put them with everyone else, hydrangea, spirea, dinnerplate hibiscus, althea. you can put around the porch if you want the privacy. other wise start with a planting about 10-15′ away. a few that would seclude the spot from the house and any one else. If this is a shady spot, azaleas are wonderful, the more the shade the more they love it. Small plants, shasta daisy, salvia, star flower, cone flowers, bachelor buttons. thymes are great for the borders, french tarragon, oreganos, possibly rosemary, lavender. these all smell lovely and can be thrown on the grill while cooking. ok the spot he planted 10-15 away. do small stools or seating area there. i also have some great diys in my hacker’s delight idea book. repeat a water/fire feature there for a private reflective spot. place pavers in a swirling path to this spot. I would put down, every fall, bags of mulch, top soil, etc. in a spot. when spring comes, spot will be minus grass etc. in spring make a bed. until there is no more grass. I am done.
The Centaurea montana flower was introduced to Britain from mainland Europe’s woodlands and mountain meadows sometime in the 16th Century. Also known as the “perennial cornflower”, this spreading evergreen has been grown in English gardens for centuries and its popularity continues to this day. Follow our cornflower grow guide and get your own gorgeous blooms growing today!
The Genus of Centaurea
Why do we love bushy, thistle-like plant so much? Explore with me further to find out the cornflower’s many wonderful qualities and why, in my humble opinion, it’s an essential perennial for garden borders.
There are so many planting choices for a flower garden. In fact, there are many more flowers than you could ever think of, for every soil and site possible. One reason we love this unusual leggy perennial has to be its ability to adapt to any given conditions. Once planted and given time to settle in, it’s basically there forever.
As a recognized naturalizing flower, it belongs in country cottage gardens, and formal estate gardens alike. Wherever you plant these colourful, clump-forming cornflowers, they bring a wealth of structure and colour. Furthermore, and most importantly, they attract a wide array of garden wildlife.
The cornflower belongs to the European Centaurea family. This is a genus of annuals and perennials that are grown for their intriguing, thistle-like flower heads. The Centaurea montana, our dear friends and most popular cultivated species, have purple thistle-like flower heads. Each head encased is by a ring of the brightest blue, slender ray petals. Together, the flower heads look like a mass of colourful stars.
Cornflower foliage has the same thistle-like appearance. Its growth is vigorous, grey-green in colour, and has an almost furry appearance from the thousands of tiny silvery hairs. The leaves, however, are long and ovate, not serrated like a thistle, and have a noticeable white mid-rib. Being an evergreen plant, they remain this wonderful silvery-green colour all year round.
Other cornflower species have alternative flower colours. In fact, some are purple, blue, white or pink, but all have similar foliage. We shall delve into other interesting varieties a little later on.
Centaurea Species’ Growing Habit
These are plants of a bushy habit, with a rather untidy and leggy appearance. I tend to create structure for mine when they’re placed at the front of a border. They can be better when planted in between other perennials a little further back. Additionally, this gives the stems more structure, as plants on either side help to hold them together, curtailing their wanderlust tendencies.
By mid summer, I recommend cutting them back to secondary stems. This will encourage more and more flowers. At full maturity, a height of up to 70 cm can be expected from these rather wonderful and old-fashioned sun-lovers, with a spread of around 60 cm wide.
It’s late January, and I actually see a small selection of flower buds on my cornflowers as I write this article. This is proof of how hardy and resilient they are to English weather. They’re true warrior plants!
I have listed some of the best varieties that I have come across, but take a look for yourselves and see which you prefer.
Centaurea montana “Carnea”
As with all cornflowers, the “Carnea” has an extended flowering season. As such, it provides valuable garden colour after other perennials have finished blooming. The flower heads consist of a deep pink and purple thistle surrounded with an outer ring of soft pink ray petals.
These very intricate blooms appear in May and continue through to the end of July. With a height of 45 cm and a spread of 60cm, the “Carnea” is a perfect front-of-border plant. It performs best in any sunny, well-drained spot.
Centaurea montana “Gold Bullion”
The name refers to this Centaurea’s golden-green foliage. It provides a bright, contrasting backdrop to the perennial cornflowers’ purple and blue flower heads. It’s similar in height and habit to the previous, but with a mass of lighter, golden foliage. Performs best in any well-drained soil in a sunny spot.
Centaurea montana “Amethyst in the Snow”
This magnificent perennial cornflower was introduced in 2002. Additionally, it’s the first bicolour cultivar of the “C. montana” species to be introduced. Alongside the low-growing, grey-green foliage, the deep amethyst and snowy white flower heads create a truly remarkable display from early May to the end of June.
It’s smaller than other varieties at just 40 cm tall, and great as a border “front runner”. Performs best in well-drained soil in a sunny spot.
Centaurea montana “Jordy”
The “Jordy” is a new twist on a classic cottage garden perennial. Its form and foliage are similar to type, but the entire flowers are stunning deep purple-plum in hue. I think this will become a very popular variety due to richness of colour. In my opinion, this would look stunning planted in a white flower bed—a superb contrast for dramatic effect.
Perennial Cornflower’s Medicinal Properties
Back in the Ancient Greek times, it is said in Greek mythology that the Centaurea’s magnificent healing properties helped to cure Chiron the Centaur when Hercules shot him with a poisoned arrow.
After much research on the subject, it’s clear that our common perennial cornflower has extensive medicinal values. In folk medicine, it has long been used for gynecological conditions, digestive problems, and skin complaints.
It seems this little garden flower is a powerful anti-inflammatory and analgesic. In addition, it’s valued as an anti-ulcerogenic, anti-fungal, and anti-bacterial treatment.
Cornflower tea is known to reduce fever, water retention and chest congestion.
Whoever would have thought it?
Planting your Centaurea
When to Plant
Plant a pot-grown specimen at any time of the year. Ensure that your soil is well-drained, and add some extra organic matter, which will help provide essential nutrients.
Alternatively, when buying seeds, these need to be planted in the early spring time when the risk of frosts has passed. Ensure your seed are of good quality and from a reputable seller, to avoid any disappointments.
I always plant my seeds into seed trays filled with a very fine compost and start them off in the greenhouse. This ensures good seed-to-soil contact and adequate temperatures, both of which are required for successful germination. Once I have some nice strong seedlings, I plant these in my flower beds around 12 inches apart with a little homemade compost.
Where to Plant your Seedlings
We’ve already established that cornflowers are a pretty versatile plant species. They will grow in almost all soils, apart from those with a large clay base, as they become cloggy and waterlogged.
The best site is a moderately sheltered one, in full sun or partial shade.
Staking your Plants
I only give my cornflower plants structure when they’re at the front of a border. You can use small canes or metal hoops to keep your flowers in the bed, rather than spilling out onto the pathways. When planted further back in the border, other herbaceous plants and shrubs tend to do this job just fine.
Caring for your Cornflowers
Watering and Fertilizing
Cornflowers are easy to look after, and practically thrive on neglect. They are quite drought tolerant, once planted and settled, and hate to be in waterlogged soil. I would let the weather take care of the general watering, unless there is a long dry spell and your plant starts to look somewhat insipid.
I use a slow-release fertilizer for all of my plants, which I combine into the planting mix. Throughout the productive growing season, I choose a balanced liquid feed which I dilute and use once every three weeks throughout the Summer months.
Pruning and Cutting Back
You can extend your cornflowers’ flowering period by cutting the long stems back to secondary stems. Do this once the first flowering period of flowering has come and gone—usually by mid summer. This promotes more flowers and keeps your flowers from getting too untidy. When they’ve bloomed again, cut the stems back to the basal mound.
Propagating from your Cornflowers
Multiply your plants by dividing large perennials in either autumn or springtime, and re-planting them where you wish. When lifting your cornflower plants, it’s worth noting that even the smallest piece of stem left in your soil will eventually grow and regenerate.
Pests and Diseases
Both of these common problems are of minor concern when growing Cornflowers. There’s a chance of powdery mildew on the foliage when the weather is hot and humid, but this isn’t common.
Aphids—those problematic sap-suckers—can be a problem, but I just give them a dose of insecticidal soap spray and that seems to do the trick.
Good Border Companion Plants
I like the mixture of blues, purples and whites in a flower bed. To me, this just works so well and creates more of a visual impact. With this in mind, I’d suggest planting your Centaurea montana with Phlox douglasii “White Admiral”, the lace flower “Orlaya grandiflora”, Delphiniums (both royal blue and white varieties), and White Lupins. Also add some glaucous foliage plants, such as Artesmia, Lavender and Euphorbia.
Trust me, the effect is truly stunning.
Three reasons to cut back perennials after flowering
Early summer is a crucial time for looking after your herbaceous perennials. Cutting back perennials before they have flowered, often known as the Chelsea Chop, will promote healthy growth, optimise their flowering potential and keep your borders looking their best.
Discover eight reasons to prune in summer
You can also cut back early-flowering perennials such as hardy geraniums, foxgloves and primulas, right after they have flowered. Discover three reasons why, below.
Early summer is a crucial time for looking after your herbaceous perennials.
Promote more flowers
Herbaceous perennials that flower in early summer, such as hardy geraniums (pictured), alchemilla and stachys, can be cut to the base as soon as the main flush of blooms starts to fade. In an early season, this will be towards the end of June. Pruning encourages new growth and a second flush of early blooms in late summer or early autumn.
Extend the life of plants
The flower stalks of short-lived perennials, such as lupins (pictured) and many foxglove species, should be cut back as soon as the blooms on the lower half of the spike have faded. This diverts energy away from seed production (which can often lead the plant to die) and into leafy growth instead, promoting healthy growth for another season.
Keep borders looking good
Perennials that bloom in spring or early summer can look messy by June or July, with the foliage of plants such as oriental poppies (pictured) and some primulas turning yellow or brown. Cutting it back will smarten up your borders, either sending the plants into their summer dormancy or spurring them on to produce fresh foliage.
Lots of plants can be pruned as summer progresses, including spring-flowering shrubs and fruit trees. Find out what to prune in summer.
Use sharp secateurs
Make sure your secateurs are sharp when cutting back the current season’s growth on perennials, so that you don’t crush the juicy stems.
1. What are the best qualities of the hardy geranium?
They are so versatile – there are varieties that will grow in the most inhospitable places. G. phaeum and G. nodosum are both perfectly happy in dry shade, while G. macrorrhizum and G. x cantabrigiense spread across the soil forming a thick ground cover so that there is no need for weeding.
Chris BurrowsGetty Images
2. How do you recommend growing them?
I don’t advise growing them anywhere special; there are so many varieties and they all need different conditions. I grow most of those I sell in the garden so that visitors can see what does best where – and I’m delighted if a customer comes to me with a query about a problem shady area they need to fill.
3. When would you recommend cutting back hardy geraniums?
I cut G. phaeum back after flowering to stop it self-seeding and then the new foliage that is subsequently produced lasts all through the winter.
We grow it under our hawthorn hedge and water rather than feed it when we cut it back. I cut the other varieties back when they start to look untidy.
4. What do you feed them?
Nothing other than a top dressing of garden compost in March when we tidy the plot – not too much or you get more foliage than flowers. I occasionally use well-rotted manure instead.
Dan RosenholmGetty Images
5. Do they benefit from regular dividing?
I divide them if the clumps get too large, otherwise only when I am splitting them up in order to create plants to sell. Some varieties are more invasive than others – which should be avoided in small areas?
Any G. x oxonianum, eg ‘Wargrave Pink’, should come with a warning – they spread very quickly and self-seed vigorously. They are ideal if you have a space you wish to fill, for instance under shrub roses where they will flower for months, but these varieties are not suitable for small gardens.
Geranium pratense also tends to seed everywhere but I love it in our meadow where it has self-sown in every colour variation from navy blue through pale blue to pinks and white.
6. Are there any pest or disease problems?
No, but I do have trouble growing G. cinereum because it needs dry conditions and also tends to get swamped by its neighbours. That’s why it is best grown in troughs or raised beds.
5 TOP RECOMMENDED VARIETIES OF HARDY GERANIUMS
Plenty of large pink flowers with petals edged in white, 25cm.
2. ‘Derrick Cook’
Very big white flowers with distinctive pinkish-red veins, similar to G. clarkei ‘Kashmir White’ but spreads slowly and flowers for most of the summer, 40cm.
A sterile cross between G. psilostemon and G. endresii, taking the best characteristics from both parents. Magenta flowers with a dark eye, flowering for most of the summer; not as tall so never needs staking, 75cm.
4. G. maculatum
Flowers early and has pretty bowl-shaped blooms. Several colours from white through to rosy pink: newer varieties ‘Expresso’ and ‘Elizabeth Ann’ have chocolate-brown foliage and pale pink flowers, 60cm.
Large blue flowers with a white eye. Needs sun and is best grown sprawling through other plants. Blooms from mid-summer until the first frosts, 45cm.
For more information on Stillingfleet Lodge Gardens & Nurseries, call 01904 728506 or visit their website.
This feature appeared in Country Living magazine. Subscribe here.