Growing Bottlebrush Plants – Learn About Callistemon Bottlebrush Care

Bottlebrush plants (Callistemon spp.) get their name from the spikes of flowers that bloom at the ends of the stems, bearing a strong resemblance to a bottle brush. Grow them as shrubs or small trees that grow up to 15 feet. Most bottlebrush varieties bloom over a long summer season in shades of red or crimson. One exception is C. sieberi, which has light yellow flower spikes.

Bottlebrush plants need a very mild climate. If you live in an area cooler than USDA plant hardiness zones 8b through 11, grow bottlebrush in pots that you can move to a protected area for winter. Use a rich, peaty potting soil with a few handfuls of sand added to improve the drainage. If pruned hard every year, the plants will grow in pots as small as 6 to 8 inches in diameter. If you plan to let the shrub grow, you’ll need a large tub.

How to Grow a Bottlebrush

Outdoors, plant bottlebrush shrubs in a sunny location. The plants aren’t picky about the soil type as long as it is well drained. If the soil is very poor, enrich with compost at planting time. Once established, bottlebrush plants tolerate drought and moderate salt spray.

Callistemon bottlebrush care consists of regular watering while the tree is young and annual fertilization until it matures. Water young trees weekly in the absence of rain, applying the water slowly to saturate the soil as deeply as possible. A layer of mulch over the root zone will slow the evaporation of water and help prevent weeds. Use a 2-inch layer of shredded hardwood or bark or a 3- to 4-inch layer of light mulch such as pine straw, hay or shredded leaves.

Fertilize bottlebrush shrubs for the first time in their second spring. A 2-inch layer of compost over the root zone makes an excellent fertilizer for bottlebrush. Pull back the mulch before spreading the compost. If you prefer to use a chemical fertilizer, follow the instructions on the label.

Bottlebrush plant pruning is minimal. You can grow it as a shrub with several trunks or prune it back to a single trunk to grow it as a small tree. If you grow it as a tree, the drooping lower branches may need cutting back to allow for pedestrian traffic and lawn maintenance. The plant produces suckers that should be removed as soon as possible.

Named for their bottle brush-shaped flowers, this plant can grow as a bottle brush tree or a shrub. Originating in Australia, there are around 50 species of bottle brush plants, each one with a slightly different growth pattern.

Great attractors of pollinators, the bottle brush tree is a close relative of the paperbark melaleuca. It’s such a close relative, in fact, that all but four varieties have been moved to the melaleuca category!

While commercial nurseries continue to sell most bottlebrush trees as callistemon, most scientists and botanical gardens have made the transition to new names. No worries, though – I’ll make sure you have both to choose from.

No matter if you choose to grow your bottle brush plant as a shrub or as a full bottle brush tree, you’ll enjoy the bright spikes of color! And so will the local butterflies and bees.

Bottle Brush Tree Overview

Common Name(s) Bottle brush tree, bottle brush shrub, bottle brush plant, Mallee bottlebrush, prickly bottlebrush, scarlet bottlebrush, common red bottlebrush, common red bottle brush, crimson bottlebrush, lemon bottlebrush, green bottlebrush, Albany bottlebrush, narrow-leaved bottlebrush, pine-leaved bottlebrush, stiff bottlebrush, fibrebark, paperbark, lesser bottlebrush, tubada, gold-tipped bottlebrush, white bottlebrush, willow bottlebrush, weeping bottlebrush, creek bottlebrush
Scientific Name Callistemon brachyandrus, Melaleuca brachyandra, Callistemon citrinus, Melaleuca citrina, Callistemon lanceolatus, Callistemon flavovirens, Melaleuca flavovirens, Callistemon glaucus, Melaleuca glauca, Callistemon speciosus, Callistemon linearis, Melaleuca linearis, Callistemon pinifolius, Callistemon rigidus, Callistemon nervosus, Melaleuca nervosa, Callistemon nervosum, Callistemon phoeniceus, Melaleuca phoenicea, Callistemon polandii, Melaleuca polandii, Callistemon salignus, Melaleuca salicina, Callistemon subulatus, Melaleuca subulata, Callistemon viminalis, Melaleuca viminalis
Family Myrtaceae
Origin Australia
Height Varies by species
Light Full sun
Water Drought-tolerant plant, water infrequently
Temperature 45-90 degrees Fahrenheit
Humidity Tolerates humidity
Soil Well-draining, low alkalinity
Fertilizer Balanced 8-8-8 slow-release fertilizer in spring, summer, fall.
Propagation By seed or cuttings
Pests Sawfly larvae, scale, web moth (webbing caterpillar). Also susceptible to fungal diseases like root rot, stem disease, powdery mildew, and leaf spot.

Types Of Bottle Brush Tree

As I mentioned above, there’s around 50 different species of bottle brush trees, and some confusion in the naming. I can’t cover them all today, but let’s go over a few of the best-known melaleucas and callistemons!

Callistemon brachyandrus

‘Melaleuca brachyandra’, ‘Callistemon brachyandrus’, ‘Mallee Bottlebrush’, ‘Prickly Bottlebrush’, ‘Scarlet Bottlebrush’

Callistemon brachyandrus. Source: Akos Kokai

Sharp-tipped leaves are the origin for the “prickly” name for this plant, and it definitely fits. Up to 2″ in length, these pointy leaves require the use of gloves to prune, but the flower stalks more than make up for the trouble.

Those flowers are actually clusters of 7-36 small flowers with extremely long stamens. The stamens are bright scarlet in color with yellowish-green tips, giving them a distinctly dual-colored look.

Visually stunning to look at, this plant can grow from five to thirty feet in height.

Callistemon citrinus

‘Melaleuca citrina’, ‘Callistemon citrinus’, ‘Callistemon lanceolatus’, ‘Common Red Bottlebrush’, ‘Crimson Bottlebrush’, ‘Lemon Bottlebrush’

Callistemon citrinus. Source: TCL 1961

One of the very first Australian plants to be taken out of the country in the 1770’s, the lemon bottlebrush is a popular variety. It produces a profusion of brilliant crimson flower stalks that bloom year-round, washing across the plant in a fiery wave.

Some cultivars produce vivid pink or white stalks as well.

Grown quite often as a tree, melaleuca citrina gets its citrus-related names from the scent of the leaves when crushed. This scent is quite similar to various kinds of citrus leaves and is quite pleasant.

The leaves also tend to produce oils, allowing the fragrance to linger around the plant on warm summer evenings.

This bottle brush tree has a shrubbing habit, tending to stay in the 3-10′ range. It’s often used to create brightly-colored hedges. However, it can be trained to full tree growth as well.

Callistemon flavovirens

‘Melaleuca flavovirens’, ‘Callistemon flavovirens’, ‘Green Bottlebrush’

Callistemon flavovirens. Source: Michael Jefferies

Another bottle brush tree that stays towards the smaller side, the green bottlebrush averages a 3-10′ height.

This plant sends out flowers from May through December in shades which range from a pale green to a cream or white color. Each is tipped with light yellow, giving that multilayered coloration that bottlebrush plants are known for.

New leaf growth is silvery, but darkens to a medium green tone against the dark, woody bark. Unlike some of the other bottle brush varieties, this plant produces egg-shaped leaves with the narrower part of the egg towards the stem.

Callistemon glaucus

‘Melaleuca glauca’, ‘Callistemon glaucus’, ‘Callistemon speciosus’, ‘Albany Bottlebrush’

Callistemon glaucus. Source: Wildlife Travel

Widely grown as an ornamental, callistemon glaucus tends to stay in the shrubby growth pattern of up to 10′ in height. Its leaves tend towards a lighter green with a bluish tinge to them, and are long and slender with a slightly ovoid shape.

The flower stalks for the Albany bottlebrush tend to stay in the bright red or deep red-pink range, tipped with tiny pale yellow specks.

Callistemon linearis

‘Melaleuca linearis’, ‘Callistemon linearis’, ‘Callistemon pinifolius’, ‘Callistemon rigidus’, ‘Narrow-Leaved Bottlebrush’, ‘Pine-Leaved Bottlebrush’, ‘Stiff Bottlebrush’

Callistemon linearis. Source: Maggi_94

As you can tell, this plant has had quite a number of botanical names over time. In part, that’s due to the confusion of particular cultivar names with the botanical name.

The base species has leaves which are linear in shape and about a half inch wide, where the other cultivars vary in their leaf shapes slightly.

Producing vibrant red spikes of color, the narrow-leaved bottlebrush is a good choice for people in damper or swampier locales. It is widely cultivated, but is most often seen in roadside plantings rather than garden environments.

Callistemon nervosus

‘Melaleuca nervosa’, ‘Callistemon nervosus’, ‘Callistemon nervosum’, ‘Fibrebark’, ‘Paperbark’

Callistemon nervosus. Source: Arthur Chapman

Fibrous, papery bark from this plant was used widely by aboriginal Australians for carrying containers or padding. The oil-producing leaves were used as a decongestant, but also used in a similar way as the related tea tree plant (Melaleuca alternifolia).

With blooms in either a creamy white or a rich, dark red, fibrebark is a popular bottle brush tree to grow. It’s a distinctly tree-type plant, growing from seven to fifty feet in height.

The layered bark makes an interesting element in landscaping, and the blooms appear from April to September.

Callistemon phoeniceus

‘Melaleuca phoenicea’, ‘Callistemon phoeniceus’, ‘Scarlet Bottlebrush’, ‘Lesser Bottlebrush’, ‘Tubada’

Callistemon phoeniceus. Source: Rob Young

With a height that can soar to up to 20 feet, this bottle brush tree can be grown as either a tree or a shrub. The lesser bottlebrush is capable of growing in a number of soil types although it prefers sandier soil, and tends to transition well to unusual climates.

Spires of pinkish-red or purplish-red flowers rest above lateral blue-green leaves and rough bark. Flowering tends to be heaviest from October through January in its Australian natural habitat, but can happen at other times of year.

Callistemon polandii

‘Melaleuca polandii’, ‘Callistemon polandii’, ‘Gold-Tipped Bottlebrush’

Callistemon polandii. Source: Arthur Chapman

A hardy shrub that can grow to 10′, the gold-tipped bottlebrush is widely grown in warm coastal areas. It’s one of the varieties that has transitioned extremely well to California growing, particularly in southern or central areas of the state.

This bottle brush plant is widely used as a hedge or shrub plant, as it tends to fill out extremely well. However, it’s known to damage wastewater pipes, so avoid planting this near buried water or sewer pipes.

Callistemon salignus

‘Melaleuca salicina’, ‘Callistemon salignus’, ‘White Bottlebrush’, ‘Willow Bottlebrush’

Callistemon salignus. Source: Tatiana12

Popularly seen as a streetside tree or shade tree in a park, the white bottle brush tree can grow to heights of up to 50 feet. Its papery bark and white flowers are a popular landscape addition.

Cultivated forms can have pink or red flower stalks as well, but it’s known for its white blooms.

Its leaves have a resemblance to those of some willow species, spawning one of its common names and the reference to salix in the botanical name. The creamy white flowers tend to be a food source and draw birds of multiple types.

Callistemon subulatus

‘Melaleuca subulata’, ‘Callistemon subulatus’

Callistemon subulatus. Source: Eric Hunt

For people in more northern reaches of California and up the west coast of the United States, considering callistemon subulatus is one of their best bets. This bottle brush shrub grows 3-7′ tall and makes an excellent hedge plant, producing flowers through most of the summer months.

Hardy in many environments, this plant can tolerate cooler temperatures or extremely hot ones, provided that it has some shade. It also does fairly well with sea air, and is a popular plant in and around San Francisco.

Callistemon viminalis

‘Melaleuca viminalis’, ‘Callistemon viminalis’, ‘Weeping Bottlebrush’, ‘Creek Bottlebrush’

Callistemon viminalis. Source: Ahmad Fuad Morad

Last on the list, but definitely not least, is the weeping bottle brush. Possibly the most cultivated of the bottle brush plants in garden settings, this is absolutely the most popular variety on today’s list!

Raised either as a shrub or as a multi-trunked tree that can reach heights of 30 feet, the weeping bottlebrush provides food for nectar-consuming wildlife.

Its dense root system is used to reinforce riverbanks, as the roots mat together and help to prevent erosion.

Callistemon viminalis is not frost-hardy, and has issues with salt spray. However, it can be grown in most environments if protected from cold or sea air. This plant has become popular around the world for its brilliant red profusion of flowers.

Bottle Brush Tree Care

Once established, care is super-simple: water it when the soil starts to dry out, and give it some fertilizer at regular intervals. Young plants require a little more preparation, though.

Read on to find out the best way to prepare your bed and care for your bottle brush tree!

Light

A red-flowered melaleuca nervosa. Source: Arthur Chapman

Before you plant your bottle brush plant, it’s important to be sure your sun conditions are going to be right.

First, consider your bottle brush tree species. The vast majority of them prefer full sun, but there are a few of the shrubbing types which can tolerate partial shade.

Second, make sure that sun will reach that spot in the winter. A south-facing placement usually ensures you should have adequate sunlight for most callistemons all year.

As bottle brush plants do well in zones 9-11 normally, they tend to have good resistance to too much heat. They won’t like the cold, however. Some varieties can take low temperatures, but they are not able to handle repeated frost conditions.

If you live in a location where you get snow or extremely cold conditions during the winter, you should keep your bottle brush tree in a shrubbery-type growth type and plant it in a container. That way, you can optimize placement for light, and it can be brought indoors with a grow light for the winter months.

Older bottle brush trees which have gained significant growth can tolerate cold weather better than those which are young.

Water

The average bottle brush is going to prefer regular watering, but it won’t necessarily require daily watering as these plants tend to be somewhat drought-resistant.

Depending on its specific species, age or size, watering requirements vary widely. However, a good rule of thumb during the first year or two is to check the top four inches of soil at the base of the plant. If it is damp, you’re giving it enough water. If it’s powdery and dry, it needs watering.

To develop a good root system, I recommend slow, deep watering patterns. Using a drip system or soaker hose will provide these conditions and help encourage the root mass to expand as necessary.

Established plants that are more than two years old are much more drought-resistant than younger plants. These have had plenty of time to establish a good root system. Water older bottle brush trees during prolonged dry periods or when trying to stimulate flowering.

You’re welcome to water more often, as long as the soil drains really well. However, be careful not to overwater!

Bottle brush trees can withstand short periods of flooding, but try to avoid standing water once floodwaters recede.

Melaleuca nervosa bark, also known as paperbark. Source: Arthur Chapman

Soil

Bottle brush trees grow well in a wide variety of soil conditions. In the wild, they often grow along creek beds or in sandier soils, but some species do extremely well in clay as well. Some species have extensive matting root systems that can help prevent erosion, even with sandier soil.

Still, one thing which should always be avoided is highly alkaline soil.

Too much alkalinity will cause bottle brush trees to suffer yellowing of their leaves from chlorophyll loss. If leaves remain yellow for too long, the plant will die off as it can’t process sunlight properly.

For overall best results, go for a pH range between 5.5 and 7. Work in some compost to add nutrients, and perlite to slightly loosen clay-type soils. If you have sandier soil naturally, skip the perlite and simply work in compost.

Your overall goal is to have a soil which the roots can easily permeate and which remains damp, but not wet. Application of a few inches of mulch around the base of your plant will help keep the soil moist.

Fertilizer

A closeup of a Callistemon glaucus flower. Source: caz15x

I like to use a balanced, slow-release fertilizer for my bottle brush shrub. Applied evenly at the beginning of the spring, summer, and fall, an 8-8-8 slow-release fertilizer will encourage steady growth and flowering.

You don’t need to fertilize in the winter, as the plant simply won’t need added nutrition then.

A little extra phosphorous can help stimulate flower production in the right season and at the right time. The problem is that it needs to be applied a few weeks before normal flowering begins.

If you’re not sure when flowering should happen for your plant, it’s best to stick with a balanced fertilizer.

Propagation From Cuttings

It’s extremely easy to start your bottle brush tree from either seed or cuttings.

For cuttings, you want to take 6-inch cuttings from semi-matured wood. The best time to do this is during the summer. Use sterilized pruners to take the cutting.

Once you have your cutting, pinch off any lower leaves on the stem and any flower buds. Dip your cutting into a rooting hormone powder and then put it into your growth medium. You can use perlite, potting soil, or a number of other starters as growing medium.

Make sure the medium is damp, and then cover the cutting with a plastic bag to help keep moisture inside. You can base-water by setting your potted cutting into a tray of water if necessary, but avoid overwatering.

Wait for the cutting to take root, which should happen within 9-10 weeks, then remove the bag and acclimate your plant to the lower humidity before repotting.

Propagation From Seed

A closeup of seed pods from callistemon linearis. Source: John Tann

If you have seed, it’s simple enough to plant, but it will take a bit longer for your plant to become hardened to the weather. To give it the best chance, sow your seed during the springtime in a balanced potting mix.

As bottle brush plant seeds are extremely tiny, they will resemble dust. This means you’re likely to sow them rather heavily, but that’s okay. Thin down excess plants and keep the strongest specimens as they appear. Try to leave a few inches of space between plants.

Once they’re at least 6-8 inches in size, you can gently separate them and repot them.

Keep in mind that if you are growing different varieties of bottlebrush plants, they hybridize easily. The best way to keep the same features as the parent plant is to take cuttings.

If you’re only growing one variety, the seeds should produce true clones of their parent plant in most cases.

Transplanting

Transplanting your bottle brush requires some preparation of the soil. Read the “soil” segment above for more information.

For older bottlebrush trees, you will want to prepare a hole based on the size of the current plant roots. If the roots have a foot and a half spread, for instance, you want to prepare a hole that’s at least two feet deep and three feet across at the topmost point.

Preparing the soil in advance loosens it and makes it easier for the roots to spread out in. As much of the root mass will be a tangled mat near the surface, you need to ensure that there’s plenty of room for those roots to adapt to!

Young plants need a smaller prepared space. A good rule of thumb is double the root mass in width, and at least 1.5 times the root mass deep. This gives plenty of good aeration.

Potted bottle brush shrubs should be given 3-6 extra inches of space in their pot when transplanting to a new pot.

Pruning

This Callistemon linearis has been trained in an espalier style. Source: wallygrom

There are two types of pruning which are commonly done for bottlebrush shrubs or trees: tip pruning, or flower pruning.

Tip pruning should be done when the new growth is still extremely young, and before it’s had the chance for the stem to harden in any way.

As flowers will grow from these tips, you may sacrifice some flowers if you prune the stems too late. However, this will help you shape the plant if necessary.

Flower pruning is done just as the flowers are beginning to fade. Neatly snip off the flower just behind the lowest set of blossoms, leaving as much stem intact as you can. This may spur additional flower growth from the same stem.

You can prune to train your bottle brush plant to a specific growth pattern. Bottle brush trees also work well for the traditional practice of espalier, or training against a wall or building.

Collecting Seeds

The seed pod on the left is nearly ready to harvest. The one on the right isn’t dry yet. Source: John Tann

If you want to gather seed from your bottlebrush tree, be sure to leave the flowers intact even after they’ve faded. That flower stalk is where the seed pods grow.

Pollinated flower stalks will form seed heads filled with multiple seed pods. Initially, these will be greenish, but over time they will dry to a dark, hardened brown.

As they start reaching the brown and hardened stage, place a paper bag over the top and rubberband it in place beneath the seedhead securely. Wait for a bit longer, and then cut off the stem below the seedhead and leave it to completely dry out.

The seed pods will open on their own as long as they’re kept in a warm, dry place, and a good shake will release the seed into the paper bag.

Scale insect damage on bottle brush tree. Source: Doug Beckers

The majority of your problems will arise from overwatering. But there are a few pests which can attack your bottle brush. Let’s go through the possible issues that might arise and how to deal with them.

Growing Problems

Winter’s chill can cause leaf browning on your bottle brush tree. But do not panic! As long as the branches themselves are not dead, it can recover.

If you’ve had a sudden cold snap, consider wrapping plastic or burlap around your plants to keep them a little warmer.

Be sure to leave ventilation at the top and underside of the plant so you don’t develop powdery mildew or leaf spot. Remove it as soon as the weather warms back up.

Pests

There are a few pests that attack bottle brush: sawfly larvae, scale, and the web moth (also referred to as the webbing caterpillar).

The sawfly itself will not harm your plants, but their larvae assuredly will. These sawfly larvae cause skeletonization of leaves and defoliation.

You can eliminate the larvae with a number of products including neem oil or a more potent azadirachtin spray like AzaMax. Also consider spinosad sprays like Monterey Garden Insect Spray, or even dusting the plant with diatomaceous earth.

Scale insects are a bit more irritating, as they can be hard to spot hidden on the underside of leaves. These cause pale trails to form through your bottle brush leaves.

For small infestations, you can carefully scrape the scale off, or blast it off with hard sprays of water. Larger infestations respond well to the use of neem oil or AzaMax.

Finally, the most destructive pest to bottle brush shrubs is the web moth, also known as the webbing caterpillar. These pests will attack younger foliage, webbing it together to form a cocoon. They can defoliate plants quickly, and one of their favorite targets is the bottle brush.

If you see any branches or leaves pulled together to form a cocoon, or dust that looks like sawdust near a web-coated section of branch, remove it immediately and dispose of it. This should remove the web moth larvae.

While I don’t know if it’s been tested against webbing caterpillars, bacillus thurigiensis (also known as BT) should help destroy these larvae. It’s certainly worth the effort!

Use a product such as Monterey BT if you wish to see if the bacillus will deal with your caterpillar problem, being sure to thoroughly soak through any cocoons to hit the webbing caterpillars within.

I really dislike suggesting inorganic methods to combat a pest. However, if you do not trim off visible cocoons and the BT doesn’t work, you may have to resort to the use of a carbaryl insecticide such as Sevin. This is known to be extremely effective against web moth larvae.

Diseases

Root rot can affect bottle brush trees if the soil is consistently too wet. This soggy soil promotes the growth of fungi that cause the root rot. It can cause yellowing of leaves, discoloration of the trunk, dying back of branches, and can lead to plant death.

To avoid this, water your bottle brush plant only when it needs it, and water slowly but deeply to allow water to penetrate the soil and drain off well. If necessary, apply a copper-based fungicide such as Bonide Copper Fungicide as a soil drench to try to kill off the fungal growth.

Another disease, stem disease, develops also from overwatering. Stem disease is a bacterial issue that also enters at the roots but travels to the branches. It causes stunted, thin branch growth and can slowly kill your plant.

Ensuring your plant has full sun will help water evaporate from the soil more quickly, but the easiest way to avoid this is to simply not overwater. Treatment is withholding water until the soil is dry, then only water enough to just barely dampen the soil.

Limit the plant’s exposure to water until it recovers from the bacterial infection, and prune damaged branches. Be sure to sterilize your pruners to avoid cross-contamination.

Powdery mildew is caused by dampness on leaves where yet another fungus can develop. This one, at least, is relatively easy to treat! Spray all plant surfaces, both tops and bottoms, with neem oil. Retreat every few days until the powdery mildew is gone.

Leaf spot is the final fungal growth that can become a problem.

While a few spotted leaves won’t harm anything, if the fungal growth spreads throughout the plant’s leaves it can cause plant death. Avoid watering the foliage, which is where the fungi develops if it remains wet for too long. Ensure the plant has plenty of airflow around it to keep leaves dry.

Ready to benefit from the bounty of beneficial pollinators that your bottle brush bush will bring? (Boy, that’s a lot of B-words!) In all honesty, these white, pink, or red bottle brush trees are beautiful additions to your landscaping, and they’re surprisingly easy to take care of once established. What’s your favorite shade of bottle brush tree? Tell me below!

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The bottlebrush tree, despite its name, is actually a shrub. It is most often grown as a large shrub or shaped into a small tree with particular pruning. The common name of bottlebrush refers to the plant’s blooms, which are a spiked flower sitting at the very end of a stem, looking remarkably like a brush used to clean bottles or jars. They can be quite large, reaching up to 12 inches long in some species. Made up of many individual blossoms, these flowers are typically produced in various shades of red, and are a good way to attract hummingbirds, butterflies, and other wildlife.

Bottlebrush Tree Overview

Quick Facts

Origin Australia
Scientific Name Callistemon
Family Myrtaceae
Type Evergreen shrub
Common Names Bottlebrush tree, crimson bottlebrush, red bottlebrush, green bottlebrush, yellow bottlebrush, bottlebrush plant, bottlebrush shrub, weeping bottlebrush
Ideal Temperature 50- 90° F
Light Full sun
Watering Moderate
Humidity Moderate

Caring for Your Bottlebrush Tree

Watering

This plant should be moderately watered when it is young, though it will become drought-tolerant once it is established (Australian National Botanic Gardens). In spring and summer, you should water the plant once a week if it hasn’t recently rained, showering the plant slowly to give the water a chance to be full absorbed deep into the soil.

Layering mulch over the soil will help with water-retention, reducing the amount of water that evaporates, leaving the soil in a more moist condition. As with any plant, be careful not to over water in order to prevent root rot. Root rot is usually fatal for bottlebrush trees and cannot be remedied. Your best protection against root rot is prevention, ensuring you don’t provide the plant with more water than it needs. This is especially important if you grow your bottlebrush tree in a container, as the soil will hold onto the water due to it having less opportunity to drain than ground soil.

This plant is not especially fussy when it comes to soil and will happily grow in any type of well-draining soil. You can always add builders sand to your soil mix to help it drain better and reduce the chances of root rot occurring.

Temperature

As a native of Australia, this plant likes to be kept warm. In mild climates, it can live all year round, though if you live in an environment where winters are cold, then you will need to grow the bottlebrush tree in a container so that it can be moved inside during chilly months.

The bottlebrush tree thrives in full sun and needs plenty of direct sunlight to produce the striking brush-like flowers

The bottlebrush tree thrives in full sun and needs plenty of direct sunlight to produce the striking brush-like flowers. If you are planting this tree directly into the ground in your garden, ensure it is in an area that will get at least six hours of sun a day. Watch out for neighboring plants which might grow bigger than the bottlebrush tree, resulting in it being put in the shade by the bigger plant.

For encroaching plants, cut them back to enable the bottlebrush tree to have full access to daylight, or dig up your bottlebrush tree and replant it in a more suitable location. Bottlebrush trees in containers will need to be positioned in a sunny spot and can be moved around if necessary to give them the best chance of good health and flower production.

The bottlebrush tree only requires a light pruning. The time of year you prune this plant will directly affect its ability to flower, with continual pruning often leading to a lack of blooms the following year. The basic rules are that pruning for size or shape should be done in early spring while pruning for health and maintenance should be done in both early spring and late summer.

Bottlebrush trees can typically grow to around 15 feet in height, but if this isn’t ideal for your space, then you can trim it back each year and maintain an appropriate height. If aggressively pruned each year, you can keep the bottlebrush tree at a very compact size in an 8-inch sized pot. Although the plant is actually a shrub, some people like to prune it into the style of a tree, with long stems in place of the trunk, and an umbrella-shaped upper section forming the leafy part of the tree. This sort of pruning should take place annually in early spring before any flower buds form, as this will prevent interference with flower production.

To prune back the plant, whether it be to shape it specifically or to cut back its size, you should make your cuts on each branch just above a node. Bottlebrush trees, when done correctly, respond well to pruning. As with most shrubs, a light pruning of the stems diverts the plant’s energy into flower production, so cutting your plant back will be beneficial if you enjoy the bottlebrush tree in bloom.

Pruning for the plant’s health should be addressed twice a year, both in early spring and late summer. If flowers are still in bloom, you should delay pruning the plant, only going ahead once flowers have faded to prevent problems with growth in the future. Cut back any dead or damaged stems, and look for any inner stems which have gone brown. Brown stems on the interior of the plant are a result of lack of sunlight. To resolve this problem, you should lightly thin out the plant to enable the sun to reach more of the inner branches.

Feeding

This plant will benefit from a monthly feeding during warmer months of a fertilizer high in phosphorus. This will help the plant to produce an abundance of flowers. If you find your bottlebrush tree is struggling with flower production despite you getting all of the caring conditions seemingly just right, it could be down to using the wrong fertilizer.

Different nutrients in fertilizer have different uses. Phosphorus aids in flower development, while nitrogen encourages foliage growth. If you use a fertilizer that has a high percentage of nitrogen, then your plant will become very leafy, and this is often at the detriment to flower production. Ensure your fertilizer is either a general-purpose fertilizer with equal parts of the three main plant nutrients or one that has a higher proportion of phosphorus.

The method you use to fertilize the bottlebrush tree is personal preference and will not affect the health of the plant, providing you follow the instructions on the packaging. Many people opt for granular fertilizers for outdoor plants growing directly in the soil, while liquid fertilizer is better suited to container plants.

The bottlebrush tree is susceptible to fertilizer burn, which can cause leaf discoloration, so if you are new to using fertilizer or are unsure of the amounts to use, err on the side of caution and use less than you think necessary. A lack of fertilizer will cause less damage than using too much.

Do not fertilize this plant in the colder months as it will not be growing and therefore not need the extra nutrients.

Propagation

If you want to propagate your bottlebrush tree, you can do so from seeds or from stem cuttings (Royal Horticultural Society). Both options are easy and very rewarding to do.

To collect seeds from your bottlebrush, you will need to locate the woody fruit produced by each blossom on the plant. You will be able to find these small fruits growing along the flower stems in clusters. Remove them from your plant, unopened, and store them in a cool, dry place inside a paper bag. Then, wait for the fruits to open, revealing hundreds of tiny seeds from each fruit. Sow the seeds during spring in moist soil and wait for seedlings to appear, transferring them to slightly larger pots when mature enough and continuing care as usual for young shrubs.

Due to the common cross-pollination of bottlebrush trees, growing the plant from seed does not guarantee that the new plant will be the same variety as the mother plant. If you are keen to ensure your new plants are a direct copy of the parent plant, you will need to propagate using stem cuttings instead of seeds.

Propagation by stem cuttings can be done during summer with semi-mature woody stems. Make your cut with clean shears at a 45-degree angle to create the most surface area from which roots can form. Your cutting will need to be around six inches in length, with all of the lower leaves removed. Any flowers or flower buds will also need to be snipped from the cutting. You can dip the raw end of the cutting in rooting hormone to encourage roots to form and increase your chances of successful propagation, but it isn’t entirely essential and can be skipped if you wish.

Stand the cutting in either a jar half filled with water or in a small pot filled with soil, ensuring that the soil is packed tightly enough around the stem to prevent it from falling over. If you are using soil to propagate your stem, keep it moist but not wet, and, ideally, cover it with a plastic bag to help increase humidity.

If you are using water to propagate your stem, change it at least every other day to keep it fresh. Place the stem cuttings in a warm place, ideally with bottom heat, and no direct sunlight. In eight to twelve weeks, your stems should have rooted. If you are propagating in water, then the development of stems is easy to witness.

If the stems are in the soil, you can check to see if roots have formed by gently tugging on the stem and seeing if it offers any resistance. Stems which will easily be pulled from the soil do not have any roots, while those that hold onto the soil are showing evidence of root development. Once roots are present, you can remove the plastic covering and move the pot outside to a warm and sunny spot. Ensure the young plant is well-protected from strong winds and continue care as normal, either planting directly into the ground or into a bigger pot when the plant is strong enough.

Disease

The bottlebrush tree, in general, is quite a robust and healthy shrub, but there are some diseases that can strike the plant and cause lasting damage if not correctly treated. The most common diseases affecting the bottlebrush tree are listed below.

Powdery Mildew

This is a disease that commonly occurs in moist or damp conditions. It presents itself as a powdery white or gray covering on the plant and can appear anywhere from leaves, stems, flowers, and fruits. In severe cases, it will turn the leaves brown or yellow.

If your bottlebrush tree suffers from powdery mildew, you will need to treat it with a fungicide. The best defense against powdery mildew is prevention. Try to plant your bottlebrush tree in a bright and sunny spot away from dark and damp corners where mildew thrives. Moisture on the surface of the leaves will help mildew to develop, so try to keep the foliage dry by watering the plant from underneath. If you use sprinklers to water your plants, do so during the morning so that the sun has a chance to dry the leaves off during the day, instead of using sprinklers in the late evening.

Twig Gall

This plant problem is a direct result of overly wet soil. If you notice that your bottlebrush tree has branches and stems which are bloated in appearance, and your soil is constantly wet, then your plant is most likely suffering from twig gall. This is a fungal disease that can be fatal if left untreated but is easy to treat with high levels of recovery when spotted in good time. Simply remove any diseased branches from your bottlebrush tree and dispose of them. Sort out your wet soil problem by correcting your watering schedule, watering the plant with less frequency and with less water. Consider adding sand to the soil and mixing it in to aid with better drainage.

Verticillium Wilt

This difficult-to-diagnose disease is caused by a fungus that lives in the soil. It enters the plant from the roots and travels up the plant’s vascular system, leaving a trail of curled and yellow or brown leaves as it goes. Plants suffering from verticillium wilt also experience leaf loss and branches which die back.

Due to the fact that many other diseases or pest infestations can present in similar ways, it’s hard to diagnose verticillium wilt. One way to identify it is to slice through a stem or branch on your suspected plant. If you see dark rings of color on the cross-section, then this is a good indication that your plant has verticillium wilt. The dark circles are made by the fungal disease as it travels throughout the plant.

If your bottlebrush tree is suffering from verticillium wilt, then you have two options. You can remove and dispose of the plant, or you can try to build up the plants resistance against the disease. The fungus will remain in the soil and is hard to get rid of. If you choose to dispose of your plant, be sure not to replant anything that is susceptible to verticillium wilt in the same area. If you want to try to save the plant, prune off any infected branches and try to improve the health of the plant so that it is strong enough to fight off the disease. Use monthly fertilizer and ensure the plant has adequate water and sunlight.

Root Rot

This disease is more common in houseplants, but it can affect plants living outside as well. It is directly caused by the soil being too wet, in which a fungus develops. The fungus attacks the roots and leaves the roots unable to absorb moisture or nutrients that the plant needs, which will result in a plant that looks as though it has been suffering from drought, even though the opposite is actually the case. Plants suffering from root rot will have yellow or browning foliage, stunted growth, leaf loss, and branches that die back.

Root rot is one of the most common problems affecting plants and trees, and it is also one of the most fatal. If your bottlebrush tree has root rot, it will be difficult to save it unless you have noticed it in the very early stages. For root rot, prevention is much better than a cure. You should ensure your soil drains well, adding sand or organic matter to your soil to improve any drainage issues. Take note of your plant’s watering requirements and don’t water too frequently or too heavily. Your bottlebrush plant will much prefer to live through occasional periods of drought than continuously wet soil.

Lemon Bottlebrush Tree

Callistemon citrunus

The Lemon Bottlebrush, botanical name Callistemon citrinus, is an attractive and versatile bottle brush plant that can be used as a shrub or as a medium sized tree. From southeastern Australia, this beautiful plant features striking red flowers that resemble the look of a bottle brush. Though the flowers are bright red, the flowers have a lemony scent, hence the common name. Pollinators, butterflies, and especially hummingbirds are attracted to the fragrant flowers of this fast growing evergreen.

Homeowners will often use this plant as an effective and beautiful privacy screen hedge to block out unwanted views or for use as a border. It loves the heat, is cold hardy, and tolerates poor soil, making it a great choice for a variety of landscapes. The Lemon Bottlebrush will require low to moderate water use and loves full sun. Feel free to speak with a Moon Valley Nurseries professional for placement ideas.

Homeowners looking for an evergreen with year-round interest will admire the nice contrast provided by the red flowers and green foliage. Some utilize the pretty flowers and woody capsule seeds in floral arrangements. In fact, the Lemon Bottlebrush will bloom in winter in warmer climates, just in time for holiday floral arrangements! This plant retains its good looks all year long as the bright red flowers appear in waves throughout the year and the red new growth matures to green.

Moon Valley Nurseries offers thriving Lemon Bottlebrush plants as shrub or tree forms. It can also be pruned to form a single trunk or into a multi-trunked small tree. We grow and nurture the finest evergreen trees ready to be planted into your landscape. Homeowners can count on us for free professional planting on all box sized trees and the best warranty in the industry. Be sure to plant with our line of Moon Valley Nurseries fertilizers for spectacular results!

SelecTree: Tree Detail

General Notes

Lemon Bottlebrush is commonly grown as a shrub, or as a single trunk tree standard. It is a tough, reliable evergreen species, attractive by nature of its red brushlike flower plumes, though it is considered quite common and not especially exciting otherwise. It is especially attractive to hummingbirds. It may require regularly scheduled light top-trimming (but not necessarily shearing) of vigorous top shoots to maintain its height below 25′.

Has fragrant Leaf.

Native to Queensland, New South Wales and Victoria in Australia.

Family: Myrtaceae

Synonyms

Callistemon lanceolatus

Additional Common Names

CRIMSON BOTTLEBRUSH, LEMON BOTTLEBRUSH

Tree Characteristics

Erect or Spreading with a Low Canopy.

Oval or Rounded Shape.

Has Evergreen foliage.

Height: 20 – 25 feet.

Width: 25 feet.

Growth Rate: 36 Inches per Year.

Longevity 40 to 150 years.

Leaves Lanceolate, Medium Green, No Change, Evergreen.

Flowers Showy. Red. Flowers in Spring or Summer. Has perfect flowers (male and female parts in each flower).

Brown Capsule, Small (0.25 – 0.50 inches), fruiting in Fall Wildlife use it.

Bark Light Green or Light Gray, Exfoliating or Striated.

Shading Capacity Rated as Dense in Leaf.

Litter Issue is Flowers.

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