Dwarf bottlebrush is an exceptionally beautiful small shrub that blooms nearly all year and requires very little from its owner. Here’s everything you need to know about planting and taking care of this desert-adapted Australian native.
Dwarf bottlebrush, also called Little John bottlebrush, is a compact, mounding version of the parent plant. Its blue-green leaves contrast beautifully against its bright red flowers. This tidy, slow-growing evergreen shrub blooms most of the year.
Dwarf bottlebrush (Callistemon viminalis ‘Little John’) is a cultivar of the Australian native tree bottlebrush (Callistemon viminalis). All bottlebrushes get their name from the cylindrical, brush-like flower spike.
Dwarf bottlebrush is a low-maintenance plant. It’s happy in either full or part sun. Once established, it needs minimal irrigation. It requires almost no pruning and produces no obvious litter.
Its striking red flowers attract hummingbirds and bees. It’s generally deer and rabbit-resistant.
Why I Like This Plant
- Show-stopping floral display
- Low maintenance
- Slow-growing mound rarely needs pruning
- Garden friendly — no thorns, no litter
- Attracts hummingbirds and bees
Things to Watch Out For
Like many non-native plants, dwarf bottlebrush is prone to iron chlorosis, especially if overwatered.
Optimal Growing Conditions
If you’re thinking of adding a dwarf bottlebrush to your garden, you need to find a suitable place that will keep your plant healthy and looking good… while minimizing maintenance for you.
Here are the key factors to keep in mind.
Temperature
Dwarf bottlebrush should be grown in USDA Hardiness Zones 9 – 11. It is extremely cold-hardy and evergreen down to around 15°F.
Sun Exposure
It’s happy in either full sun or part shade, but it will bloom more in full sun.
Size and Growth Rate
Dwarf bottlebrush is considered a slow grower, and a typical specimen will eventually reach a size of 3 feet tall by 5 feet wide when mature, but it will take many years to achieve that size.
Soil
It grows well in most well-draining native desert soils — clay, loam, or sand — provided it’s well-draining. However, our highly alkaline (high pH) desert soil is not ideal. If your plant’s leaves turn yellow, it may be because your soil is too alkaline.
Other Location Considerations
Because it has no thorns, is non-toxic, and nearly litter-free, it’s a plant you can feel comfortable placing near a pool, sidewalk, or anywhere it might come in contact with pets and people.
Because dwarf bottlebrush is small and slow-growing, it’s an excellent choice to plant along walkways or driveways, near pools or patios, in small yards, or in containers.
Dwarf Bottlebrush:
The Essentials
| Common Names | Dwarf bottlebrush, Little John bottlebrush |
| Scientific Name | Callistemon viminalis ‘Little John’ |
| Origin | Australia (cultivar) |
| Plant Type | Evergreen shrub |
| USDA Zones | Zones 9 – 11 |
| Cold Hardy | To 15℉ |
| Flower Color | Red |
| Flower Season | Spring, summer, fall |
| Mature Size | 3’ high x 5’ wide |
| Growth Rate | Slow to moderate |
| Sun Tolerance | Full, part sun |
| Water Needs | Low to moderate |
| Pests & Diseases | Iron chlorosis |
| Garden Friendly | No thorns, non-toxic, non-allergenic |
| Wildlife | Attracts hummingbirds, bees Deer, rabbit resistant |
How to Plant
The rule of thumb when planting any shrub in the desert is to dig a hole three times as wide as the root ball but no deeper. Since it prefers acidic soil, consider amending your hole with compost or a commercial soil mix.
Top with organic mulch rather than gravel, which helps to retain moisture, increase soil fertility, and reduce alkalinity.
When to Plant
The best time to plant bottlebrush is in the fall. This gives your shrub three seasons to grow roots and get established before the following summer.
The second best time is in spring, the earlier the better. This still gives your plant time to get established before the intense heat of June arrives.
How to Care for Dwarf Bottlebrush
Whether you’ve recently planted a dwarf bottlebrush or have an existing plant in your yard, here’s how to take care of it to keep it healthy and looking its best.
How to Water New Plants
Once you’ve got your dwarf bottlebrush in the ground, watering is your most immediate concern. Here is the recommended watering schedule for new shrubs planted in the spring or fall.
| Weeks 1 & 2 | Every 3 – 4 days |
| Weeks 3 & 4 | Every 6 – 7 days |
| Weeks 5 & 6 | Every 7 – 10 days |
| Weeks 7 & 8 | Every 10 – 14 days |
After week 8, gradually extend the time between waterings.
How to Water Established Plants
As your shrub gets established, there are two watering factors to consider.
- First is how often to water. This will vary with the seasons.
- Second is how much water to give your shrub with each watering. This depends on the current size of your plant.
To determine the ideal watering schedule for any desert shrub, you’ll find everything you need to know, including easy-to-use charts, at How to Water Desert Shrubs: How Often? How Much?
Should You Fertilize?
As a non-native and prolific bloomer, dwarf bottlebrush benefits from an annual application of fertilizer.
If your plant’s leaves are turning yellow, it may have a nutritional deficiency called iron chlorosis. You can learn how to effectively treat iron chlorosis here.
If you keep one in a pot, fertilize lightly a few times a year when it is actively growing.
How to Prune
Dwarf bottlebrush has a naturally attractive mounding form and grows slowly, so it rarely needs pruning. If you do find an errant branch to prune, follow a branch back to the main stem and cut there.
If you try to shear it like a hedge or take a bit off all the ends, you will destroy its natural shape, inhibit flowering, and hasten its demise.
Never remove more than 1/3 of its growth at a time. This is not a plant to prune severely, as it may not bounce back.
Dwarf Bottlebrush Cultivars
All dwarf bottlebrushes are cultivars of weeping bottlebrush (Callistemon viminalis), a fast-growing native Australian tree that usually reaches around 20 feet tall in the desert southwest.
Dwarf bottlebrush has dozens of cultivars, but there are only a few that you’re likely to find in the desert southwest.
The first two are sold under the Australian Outback Plantation label, which can sometimes be found at Home Depot.
Callistemon viminalis ‘Better John’ is an “improved” cultivar of the cultivar ‘Little John’. It is quicker to establish, has denser foliage, and its leaves are more silver-blue in color.
Callistemon viminalis ‘Green John’ is another cultivar of ‘Little John’. It is a more compact plant, its leaves are closer to true green, and it’s less likely to get woody inside.
Callistemon viminalis ‘’Light Show’® is Sunset Plant Collection’s dwarf bottlebrush cultivar.
Don’t Confuse Dwarf Bottlebrush With…
Bottlebrush’s feathery red flowers can easily be confused with the flowers of Baja fairy duster (Calliandra californica), a native of the desert southwest.
However, their descriptive common names can help.
Bottlebrush flowers are long like a bottlebrush, while fairy dusters’ flowers are shaped like feather dusters.
These two plants also are members of similar-sounding genera — fairy duster’s Calliandra to bottlebrush’s Calliestemon.
For Plant Lovers
Dwarf bottlebrush (Callistemon viminalis ‘Little John’) is a cultivar of tree bottlebrush (Callistemon viminalis).
You may also see this plant go by the scientific name Melaleuca viminalis. There’s an ongoing debate as to whether Callistemon should be a separate genus or should be moved into the Melaleuca genus.
Many authorities now put Callistemon in the Melaleuca genus, but there are two reasons I didn’t do that here.
First, the nursery trade uses Callistemon almost exclusively, and I want you to find the right plant when you go shopping or looking for information. And unless you’re a botany nomenclature geek, you’re probably OK with that. 😉
Additionally, the Australian Plant Census, which is “the” authority on Australian plant nomenclature, is not on board with moving these plants to the Melaleuca genus. And I am happy to defer to their wishes.
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Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
Photo Credits
“Dwarf Callistemon” by Surely Shirly, Public Domain