The New Zealand tea tree (Leptospermum scoparium) is an upright evergreen shrub that features small, prickly, needle-like leaves, which are aromatic when crushed. In early summer, the plant produces showy single or double white, pink, or red blossoms that are attractive to bees and other pollinators. In fact, manuka honey, a popular honey for culinary uses and alternative medicine, is produced from the nectar that bees gather from this plant.
This shrub, which is planted in the fall or spring, can be container-grown plant or used as a garden specimen. It has a moderately slow growth rate, making it an excellent choice for containers.
|Common Name||New Zealand tea tree, tea tree, broom tea tree, manuka|
|Botanical Name||Leptospermum scoparium|
|Plant Type||Shrub, tree|
|Mature Size||6–10 ft. tall and wide|
|Flower Color||White, pink, red|
|Hardiness Zones||9–10 (USDA)|
|Native Area||New Zealand, Australia|
New Zealand Tea Tree Care
Plant your shrub in the spring or early fall in a location that provides enough room to spread. New Zealand tea tree averages around six to ten feet tall and wide, but that will vary depending on the growing conditions and cultivar. A spacing of at least ten feet apart is usually recommended for full-sized cultivars.
Mix compost into the planting area to add nutrients to the soil and improve drainage. Dig a hole that’s as deep as its root ball and about three times as wide, and firmly pack soil around the roots. Water the area well. Then, add a two- to three-inch layer of mulch, keeping it at least a few inches away from the trunk. Water your plant deeply as it grows to encourage root development.
In some tropical regions—especially Hawaii—this species has escaped cultivation and naturalized in the wild. In these areas, it is considered to be an invasive species, so consult with local authorities before planting it in your garden.
This plant prefers a location with full sun though it can tolerate a little shade. However, flowering will typically be more abundant if it is located in full sun.
New Zealand tea tree readily grows in fertile, slightly acidic soil. Its planting site also needs good drainage. The plant is fairly tolerant of poor, infertile soil, though it doesn't like heavy soil. You can amend heavy clay soil with compost or other organic matter to improve drainage.
Water young New Zealand tea tree plants regularly so the soil remains consistently moist. However, do not let the plant sit in soggy soil. Established plants like a more moderate moisture level, and they have some drought tolerance. You typically only have to water them if the soil begins to dry out from a lack of rainfall.
Temperature and Humidity
New Zealand tea tree is hardy in USDA cold hardiness zones 9 to 10. It grows best in warm climates and doesn't do well once the outdoor temperature drops below 40 degrees Fahrenheit.
However, if you live in a cooler climate, you can still grow this plant outdoors in a container. Bring the container indoors each winter and provide it with as much sunlight as possible. Move it outdoors in the spring once the temperature is consistently above 40 degrees Fahrenheit.
New Zealand tea tree grows well in high humidity, and it can tolerate dry climates if you water it on a regular basis.
New Zealand tea tree typically doesn’t require regular feeding when planted outdoors unless the soil is infertile. However, it can benefit from a layer of compost or mulch in the spring as well as a balanced fertilizer every two to three years. If container-grown, New Zealand tea tree will deplete soil nutrients faster and will likely need feeding every year with a balanced fertilizer.
Types of New Zealand Tea Tree
Here are several cultivars of New Zealand tea tree:
- 'Apple Blossom': The variety has an upright habit and reaches about eight feet tall and wide with double light pink flowers.
- 'Burgundy Queen': This is an upright, dense-growing evergreen shrub with dark burgundy double flowers. It grows up to 12 feet tall and ten feet wide.
- 'Snow White': This cultivar grows to just four to five feet tall and wide. It has profuse white blossoms.
- 'Red Damask': This variety has full double flowers of deep red. It grows six to eight feet tall.
- 'Red Ensign': This variety grows eight to ten feet tall and has dark red single-petal flowers.
- 'Ruby Glow': This cultivar is a very dense, six- to eight-foot shrub with dark red double flowers
- 'Silver and Rose': This compact cultivar, which grows four to five feet tall, has pink flowers with greenish centers.
New Zealand tea tree doesn't need much in the way of pruning beyond removing dead, damaged, or diseased wood. Right after the plant has finished flowering, you can prune it to maintain its shape, encourage bushier growth, and promote more blooms. But don't cut back more than one-third of the plant at one time.
Propagating New Zealand Tea Tree
The pure species can be propagated by collecting and planting seeds, but named cultivars must be propagated by rooting semi-hardwood cuttings because seeds are either infertile or will produce offspring that don't share the parent's characteristics. Here's how to propagate by stem cuttings:
- In early summer, use sharp, clean pruners to clip off a segment of stem containing mostly new growth with slightly hardened older wood at the base.
- Dampen the cut end of the stem, and dip it in rooting hormone.
- Plant the cutting in a mixture of perlite and peat moss or commercial potting mix.
- To speed up root development, place a plastic bag over the cutting to create a mini-greenhouse environment. Remove the bag when you tug on the cutting and you feel resistance from developing roots.
- Keep the plant in a sunny window and water it whenever the soil dries out.
- Once new leaves begin to appear, harden off the cutting to acclimate it to the outdoors.
- Continue growing outdoors in the container until it's a sufficient size to plant in the garden. This can take several years, and you might need to repot occasionally as the plant grows larger.
How to Grow New Zealand Tea Tree From Seed
If you happen to have a pure species plant, you can collect seeds from matured seed pods. Sow them in spring in trays filled with seed starter mix, just barely covering the seeds. Transplant each seedling into its own small pot when they are large enough to handle. Grow in a greenhouse or indoors for the first winter, then plant outdoors late the following spring or early summer. They will need protection from cold in their first two years outdoors.
Potting and Repotting New Zealand Tea Tree
Smaller varieties of this plant will do very well in large, well-draining pots filled with ordinary potting mix blended with sand to improve drainage. They prefer not to have their roots disturbed, so choose a large pot that gives the plant room to grow. When repotting becomes necessary, choose a larger pot and remove the plant carefully, using additional fresh soil around the existing root ball. Repotting is best done in spring.
New Zealand tea tree generally requires no winter protection if grown in its established hardiness zones, but outdoor potted plants should be shifted to a sheltered position if winter temperatures dip toward 40 degrees Fahrenheit. If grown as a container plant in cold-winter regions, make sure to move it indoors to a sunny location as colder weather approaches.
Take care that in-ground plants do not stand in cold, wet soil, as this can easily lead to fatal root rot. With both in-ground and potted plants, reduce watering during the winter months.
Common Pests & Plant Diseases
This plant typically doesn't have problems with pests and diseases. Occasionally it might acquire webbing caterpillars, borers, and scales. A horticultural oil such as neem oil is a good treatment for pest problems.
This plant can be prone to root rot if it's planted in overly-moist soil that doesn't drain well. The best defense against any problems is to provide the correct growing conditions.
How to Get New Zealand Tea Tree to Bloom
This plant generally blooms reliably and profusely in June to July provided it receives plenty of sunlight and is planted in well-draining soil. Failure to bloom is usually due to bad drainage or lack of sunlight.
If the garden soil is infertile, feed this plant monthly with a balanced fertilizer to support their heavy flowering.
Common Problems With New Zealand Tea Tree
Generally trouble-free, New Zealand tea tree sometimes develops a condition in which the leaves develop a light yellow color with darker skeletal veins. This condition is called chlorosis and develops when alkaline soil prevents the plant from properly taking up soil nutrients. This plant prefers acidic soil, so if the soil is too alkaline, amend the soil to lower its pH.
A plant that begins to wilt and collapse is probably suffering from root rot due to overly moist conditions. It can be difficult to balance water needs with this plant because too much moisture can easily kill the plant, while too little moisture will cause it to dry out and die.
How is this plant best used in the landscape?
This plant makes a good flowing specimen shrub or small tree and is frequently used as a container-grown specimen on a sunny deck or patio.
How long does a New Zealand tea tree live?
Lifespans of 60 years are recorded, but named cultivars often live 20 or 30 years because the tree's growth habit becomes ungainly with age.
Leptospermum Scoparium - Plant Finder. Missouri Botanical Garden
Hawaii's Most Invasive Horticultural Species. Big Island Invasive Species Committee