The curry leaf tree -- Murraya koenigii or sweet nim -- is a medium-sized shrub or small tree that grows to 4.5 metres (15 feet) tall and 3.6 metres (12 feet) wide. Originally from India, the herbal perennial thrives in warm climates, but in the UK you can grow the plant in a container and move it inside during autumn. The curry tree produces evergreen foliage and white funnel-shaped blooms that appear from spring to midsummer, making it a beautiful addition to any home garden. Besides its aesthetic value to the landscape, the leaves of the tree are used to flavour food.
Test the soil of the selected planting site to make sure the pH level is between 6.5 and 7, as curry trees prefer acidic soil. Amend the soil with peat moss for a pH above 7 or lime if it is below 6.5. Make sure the planting site has well-drained soil and is exposed to full sunlight or partial shade for most of the day.
Dig a planting hole as deep as the root ball of the plant, but two times as wide to provide room for the roots to spread. Add the soil to a wheelbarrow.
Add equal amounts of sand and peat to the collected soil and mix thoroughly. Lower the curry tree into the hole, spreading its roots evenly in all directions. Backfill the hole with the amended soil from the wheelbarrow and pat it down to remove air pockets.
Water the planting site deeply immediately after planting. Allow the top 10 cm (4 inches) of soil to dry thoroughly between waterings. Insert your finger into the soil to determine whether the soil feels dry or moist. Water the site if the soil feels dry.
Spread a 7.5 cm (3 inch) thick layer of mulch around the plant, 15 cm (6 inches) away from the main stem. Mulching keeps roots cool and prevents competing weeds from growing near the plant.
Fertilise the plant once every other week from late March to early September, the growing season. Use an organic fertiliser specified for use on herbs. Follow label directions for application rates and water thoroughly after application.
Inspect the plant frequently for scale insects. The parasitic insects feed on the plant's sap, depriving it of nutrients and giving infected parts a dry and shrivelled look. Prune infected parts of the curry tree to remove the pests or spray with neem or horticultural oil.
Trim the tree frequently to maintain its shape and size. Snip off wayward or crossing branches. Harvest leaves as you need them for cooking.