Purple hop bush is a large, attractive, evergreen shrub with unique, colorful foliage. Here’s everything you need to know about planting and caring for this desert-adapted shrub that hails from New Zealand.
Purple hop bush (Dodonaea viscosa ‘Purpurea’) is a fast-growing evergreen shrub. It has slender, shiny, bronzy-green leaves that look similar to willow leaves. Leaves turn reddish-purple when the weather gets cold.
It is grown in the garden mainly for its foliage, rather than for its flowers which are charming but not showy. The flowers, which resemble small Chinese lanterns, start off as a creamy yellow and gradually turn bright pink.
Purple hop bush is a cultivar of hop bush, which has a huge natural range that spans 6 continents, including parts of the Sonoran Desert. Oddly, this cultivar’s only native habitat is New Zealand.
Why I Like This Plant
- Colorful foliage, especially in winter
- Easy-care
- Can be pruned into a more formal hedge
- No thorns, relatively low-litter
Things to Watch Out For
- These plants can be relatively short-lived, 10-15 years in some instances, particularly if overwatered
- Is considered flammable 🔥
Optimal Growing Conditions
If you’re thinking of adding a purple hop bush 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
Hop bush should be grown in USDA Hardiness Zones 8 – 11. It is heat tolerant up to around 118℉ and is cold-hardy down to 18℉.
Sun Exposure
Purple hop bush grows in full sun or part shade, but its leaves are more colorful in full sun.
Size and Growth Rate
It grows moderately fast and can grow to be a large shrub, 8’ wide by 12’ tall, so give it room to grow. While it can be kept small, this will require regular pruning.
Soil
It’s not particular about soil and grows well in any native desert soil, provided it’s well-draining. Overwatering can cause iron chlorosis or root rot.
Other Location Considerations
This dense shrub makes an excellent hedge or wind block. A row of these shrubs is a great way to hide an unattractive view or soften the look of a cement block wall.
Don’t plant it right near a swimming pool. While the litter from flowers and seed pods is insignificant on the ground and disintegrates quickly, it can be bothersome in your pool.
Also, don’t plant it next to your house or near a BBQ or fire pit, since this is a flammable shrub.
How to Plant
The rule of thumb when planting any shrub or tree in the desert is to dig a hole three times as wide as the root ball but no deeper. Amending the soil is not recommended. Counterintuitively, backfilling with the same native soil you just dug up helps your plant develop a stronger root system.
When to Plant
The best time to plant hop bush 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.
Purple Hop Bush:
The Essentials
| Common Name | Purple hop bush |
| Scientific Name | Dodonaea viscosa ‘Purpurea’ |
| Origin | New Zealand |
| Plant Type | Evergreen shrub |
| USDA Zones | Zones 8 – 11 |
| Cold Hardiness | To 18℉ |
| Flower Color | Yellow-green to pink |
| Flower Season | Spring |
| Mature Size | 12’ high x 8’ wide |
| Growth Rate | Moderate to fast |
| Sun Tolerance | Full, part sun |
| Water Needs | Low |
| Pests & Diseases | Root rot |
| Cautions | Mildly poisonous, flammable |
| Wildlife | Attracts birds |
How to Care for Purple Hop Bush
Whether you’ve recently planted a hopbush 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 hop bush properly planted, watering is your most immediate concern. Here’s a 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 hop bush or 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?
While you can fertilize purple hop bush, it’s not necessary. They get all the nutrients they need from native soil.
How to Prune
Hop bush has an attractive natural shape and no routine pruning is needed, but you may want to prune it to maintain a desired size and shape.
This plant is considered a sport, which means that sections of it can revert back to its original green form. If this happens and is not to your liking, you can severely prune that section as close to the main trunk as possible.
You can selectively prune old woody branches at the base every 2 to 3 years.
It’s one of the few desert shrubs that is not ruined by shearing as a hedge, provided you don’t do it more than twice a year. The best time of year to prune is in the spring after the last frost or in the fall.
Plants can be severely pruned every 5 years or so to rejuvenate.
Don’t Confuse Purple Hop Bush With…
Don’t confuse purple hop bush with hop bush, the standard green version that is the parent plant. While it has many of the same characteristics, purple hop bush is not considered as hardy, has a more columnar shape, and is not as large at maturity.
Plant Lover Facts
The purple hop bush selection was discovered in the late 1800s by a gardener who found it growing alongside a river in New Zealand. She collected seeds and grew them in her own garden. Eventually, it was introduced to a nurseryman who started growing it commercially. This color-sport still sporadically occurs in the wild.
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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.
