Maintenance Landscaping Design

Kowhai tree is a fast-growing, deciduous tree that can reach a height of 15-20 meters. The leaves are alternate, oblong-lanceolate, and 8-15 centimeters long with a pointed tip. The flowers are yellow, tubular, and grouped in clusters of 5-15. The fruit is a blackish-purple drupe, 5-7 centimeters in diameter, containing a large, hard seed.

Alternative name

• Kowhai whauwhaupaku
  
• Kowhai ngutu kaka
  
• Kowhai pango
  
• Kowhai rangatira
  
• Kowhai tawhiti

Basic info

• Kowhai trees are native to New Zealand.
  
• Kowhai trees can grow to be up to 20 metres tall.
  
• Kowhai trees have bright yellow flowers that bloom from September to November.
  
• Kowhai trees are an important food source for the kereru (wood pigeon), tui and silvereye birds.
  
• Kowhai trees are also an important source of nectar for bees.
  
• Kowhai trees are one of the few trees that can tolerate being pollarded (a method of pruning in which the main trunk is cut back to encourage new growth).
  
• Kowhai trees have shallow roots, so they can be easily uprooted in strong winds.
  
• Kowhai trees are susceptible to a fungal disease called kowhai rust, which can cause the leaves to turn brown and fall off.
  
• Kowhai trees are considered to be a weed in some parts of Australia.
  
• Kowhai trees are protected under the National Heritage Act 199

Planting Process

1. For kowhai tree, first step is to choose the location. Kowhai tree prefers full sun and well-drained soil.
   
2. The second step is to remove any weeds and grass in the planting area.
   
3. The third step is to dig a hole that is twice the width and depth of the tree’s root ball.
   
4. The fourth step is to mix some compost or other organic matter into the backfill soil.
   
5. The fifth step is to place the tree in the hole and backfill with the amended soil.
   
6. The sixth step is to water the tree well.
   
7. The seventh step is to apply a layer of mulch around the base of the tree.
   
8. The eighth step is to water the tree regularly during the first growing season.
   
9. The ninth step is to fertilize the tree in early spring.
   
10. The tenth step is to prune the tree as needed to shape it.

Related plant:
Kowhai

Soil Requirement

About soil condition, the kowhai tree grows best in fertile, well-drained soil, though it tolerates a range of soil types as long as there is good drainage. It is also drought-tolerant once established.

About light

Like the other trees, the kowhai tree needs sun to grow. However, it is not as demanding as other trees and can even tolerate some shade. This makes it a good tree to grow in areas where there is not a lot of sun.

Good Temperature

The temperature condition is perfect for the kowhai tree. It has been grown in this climate for centuries and is very comfortable in this temperature. The kowhai tree is a hardy tree that can withstand temperatures as low as -10 degrees Celsius.

Humidity Aspect

Ideal humidity condition for this plant is around 50%. If the humidity is too low, the leaves will start to curl and turn brown. If the humidity is too high, the leaves will start to yellow and drop off.

Fertilizing

Mentioning fertilizer, this family of plant are generally heavy feeders. A good rule of thumb is to add fertilizer when you first see new leaves forming in the spring. Slow-release fertilizers are great to use because they will continually feed your tree over an extended period of time. Be sure to avoid getting the fertilizer on the leaves, as this can cause them to burn. Also, be careful not to over-fertilize, as this can lead to excessive leaf and shoot growth, which can make your tree more susceptible to wind damage.

Plant Pruning

Pruning a kowhai tree is a simple process that can be done at any time of year. The main reason for pruning is to remove any dead, diseased or damaged branches. It is also important to remove any crossing or rubbing branches to improve air circulation and reduce the risk of fungal diseases. Kowhai trees can be pruned quite heavily without causing any damage, so don't be afraid to remove large branches if necessary.

Plant Propagation

Propagation is best carried out by seed, which should be sown in autumn in a free-draining seed compost. Only just cover the seed with compost, as it needs light to germinate. Keep the seedlings in a cold frame or unheated greenhouse over winter before planting out in early summer, after the last frosts.

Growth Rate

Usually, the plant growth rate is about 3 to 5 feet per year. However, some trees may exceed 10 feet in a single year. The kowhai tree grows best in moist, well-drained soil with full sun to partial shade. It is tolerant of a wide range of soil conditions, including both alkaline and acidic soils. The kowhai tree is also salt tolerant, making it a good choice for seaside plantings.

The Problems

Common problems for this kind of plant are caterpillars, aphids, and fungal diseases. Caterpillars eat the leaves, while aphids suck the sap from the tree. Fungal diseases can cause the leaves to turn yellow and fall off.

List to Know

• Make sure to plant your kowhai tree in an area that gets plenty of sunlight.
  
• Kowhai trees prefer well-drained soil.
  
• Water your kowhai tree regularly, especially during the summer months.
  
• Fertilize your kowhai tree every few months with a balanced fertilizer.
  
• Prune your kowhai tree regularly to encourage new growth and shape the tree.
  
• Keep an eye out for pests and diseases, and treat them promptly if found.
  
• Harvest the kowhai flowers in spring and summer for use in floral arrangements.
  
• The kowhai fruits can be eaten fresh or used in jams and jellies.
  
• Kowhai wood is strong and durable, making it ideal for use in furniture or construction.
  
• Enjoy the beauty of your kowhai tree for many years to come!

Alternative Plants

• MELONS, watermelons
  
• MAPLE, sugar
  
• MAPLE
  
• JACKFRUIT, Artocarpus integrifolia
  
• KIWI
  
• KOWHAI
  
• LOTUS
  
• MARIGOLD
  
• NADI
  

Source:
Find Trees & Learn | University of Arizona Campus Arboretum
Red/Black Tree Visualization - University of San Francisco
Pruning Trees in the Home Landscape - UMD