Sophora fulvida

A small evergreen tree that grows up to 10m and 5m wide at maturity. It has an upright form but can be maintained to be smaller.

It has many hairy small crowded yellow-green or grey leaflets. Bright yellow flowers bloom in pendulous clusters from October to November. Long seed pods follow the flowers containing yellow seeds

Prefers high fertility, well-draining soils, and in full sun or partial shade. This west coast form of kowhai is wind hardy and reasonably drought tolerant but requires some wind protection when young.

Always choose healthy, well grown plants and plant after autumn rains as the soil is moist and warm and allows plants to become established before winter. This enables them to withstand dry periods during the following summer. Young plants require thorough watering during dry periods over the first two or three years mulching helps to conserve moisture and suppress weeds. Planting success is often improved on clay soils by adding extra topsoil and raising beds. Incorporate coarse sand, bark, compost or other organic material to improve soil structure.

Before planting ensure the root ball is saturated and remove the planter bag or pot with minimal root disturbance. Trim any broken roots and plant at the same level as in the container. Dig a hole twice the diameter of the root ball and firm in and water once planted. Make sure plants are watered well until established if planting in a drier period. Plant with some general slow release fertiliser, and then every spring apply an organic based fertiliser such as blood and bone at a handful per square meter. The worst fate for a tree is to be planted in a hole where the root ball is allowed to sink below the surrounding ground level. Therefore it is generally desirable to plant trees into slightly raised beds of well cultivated soil. This improves drainage and provides near surface roots with well aerated soil in which to grow.

Staking may be necessary but these trees are so slow growing that this is rarely required. Unless the soil is very wet water thoroughly after planting making sure that moisture penetrates to the depth of the root-ball. Kowhai benefit from the provision of some kind of shelter when young so the damage done to plants by salt-laden wind is reduced. The best form of shelter is to establish it from a species which is hardy to salt wind and thereby protect other plants. Wooden fences or temporary shelters made from shade cloth are also useful but can be expensive.

Mulching annually helps suppress weeds and conserve moisture. Organic materials such as sawdust and bark contribute to soil structure as they decompose but keep mulching material away from the trunk. They benefit from a dressing (50g/m2) of general purpose fertiliser in early spring as new growth begins this will encourage more vigorous healthy growth. Sprinkle evenly and work into the top 2 to 3cm of the soil taking care not to damage surface roots.

The first summer and autumn after planting is critical for young plants; water thoroughly during dry periods. Pests and diseases can have serious debilitating effects on young plants; check regularly. Check stakes and ties for chafing and constriction and remove as soon as plants are strong enough to withstand winds without damage.

Pruning is not normally required for this plant until it gets larger and may need to be pruned to maintain a good shape. Prune plants after flowering to keep them compact and promote new growth. Avoid pruning in the months between November and February as that is when borer are on the wing. Borer can be a damaging pest to kowhai, although it should also be stated that borer needs to be understood as a naturally occurring pest - one that many kowhai can live with for an extremely long time. Although borer should be avoided where possible, they do not necessarily spell a death sentence for established trees. It is worth noting here that the ability of plants to withstand (or even avoid) the influence of other organisms (such as borer) is greatly assisted by planting diverse environments.

Attracts native birds.

Avoid pruning in the months between November and February as that is when borer are on the wing. Borer can be a damaging pest to kowhai although it should also be stated that borer needs to be understood as a naturally-occurring pest and one that many kowhai can live with for an extremely long time. Therefore although borer should be avoided where possible they do not necessarily spell a death sentence for established trees. It is worth noting here that the ability of plants to withstand (or even avoid) the influence of other organisms (such as borer) is greatly assisted by planting diverse environments.

Urban Trees

Sophora is named after the Arabic word for a similar tree fulvida meaning yellow.