The lemon tree has a number of attributes that qualify it for inclusion in the modern garden’s list of core plants. When it is laden with fruit it makes an eye-catching tree, especially in a smaller garden, and as it is evergreen, it can do duty as a shade tree all year round. It will grow and produce fruit quite willingly in a large pot, making it ideal even for very small gardens, and for sunny patios. Lemons have been known since the earliest times for their many useful qualities. They were eaten to prevent scurvy and the juice was used as a beauty product to lighten skin and hair. In royal gardens, lemon trees were grown in elegant, wheeled, wooden caskets. In warmer weather the palace gardeners would move the trees outside
for everyone to admire. When the cold weather turned, the trees would be returned to the conservatory. Of course, lemons are also used extensively in cooking and baking, and to make wonderfully refreshing lemonade. In fact, for most food lovers, and almost all good cooks, it is hard to imagine life without lemons.
Location: plant lemon trees in full sun about 4 m away from any other large trees and shrubs. Protect against strong winds. In colder gardens, plant the trees against a north-facing, sun-baked wall.
Soil: make the planting hole as large as possible (at least 1 x 1 m). Set aside the quality topsoil in one pile and the subsoil in another pile. Add a liberal quantity of good compost and a handful of bone meal to each pile and mix well. Fill the hole with the topsoil and plant the tree at exactly the same height as it was planted in the nursery bag – planting it too deep can cause root disease and root rot. The subsoil can be used to top up the hole and to build a dam around the tree to direct the water to the roots. Commercial potting soil mixed with a few spades of compost and a large handful of bone meal works well for lemons to be planted in pots (use reasonably big pots). Mulch the root zone with coarse compost or bark pieces and refresh the layer regularly.
Water: trees in the ground need a regular (at least twice a week) good watering during dry spells in the summer. Potted trees need to be watered more frequently during hot weather, possibly even daily. In her book Companion Planting (Briza Publications 2007) Margaret Roberts recommends that you place a long pipe in the corner of the planting hole, forming an irrigation tube. Water poured into the pipe goes directly to the roots, ensuring that the tree always gets a deep watering without any water going to waste.
Fertilizing: lemon trees are greedy plants and need to be fed four times a year with fertilizer rich in nitrogen and potassium. The nitrogen encourages better foliage while the potassium improves the quality of the flowers and fruit. Feed in September, January, April and July, using a slow-release 3:1:5 or 8:1:5 fertilizer, and following the instructions on the packaging. A liquid fertilizer with additional nutrients is also beneficial for leaves, especially saplings and potted lemons. Add a trace element mixture (specifically blended and available at most nurseries) to the fertilizer if the leaves start turning yellow. Fertilizer needs to be applied in the drip zone (away from the trunk). Water the trees before feeding and again after feeding.