The lemonade tree is an intriguing citrus that is said to have been derived from a cross between a lemon tree and a mandarin tree sometime in the 1970s. The yellow fruit can be eaten straight from the tree and have the sweetness of a mandarin with the tang of lemon. A lemonade tree can potentially get to 5 m in height, but it can be pruned to keep it at around 2 m.
The cultivation of the tree is the same as for other citrus: a well-drained position in full sun is vital. As with any planting, the soil should be prepared in advance the tree, by digging over a reasonably sized area to at least a spade's depth, adding gypsum if there is a lot of clay and incorporating rotted organic matter. The roots of the plant should be teased out gently and the plant placed in a hole at least twice the width of the root ball. The plant should be put in at the same depth it was in the container, with top of the root-ball should be level with the surrounding soil. Water well and keep it well watered for the next few weeks. Once established, citrus trees need regular watering and love to be fed every few months, using something like Organic Life or Dynamic Lifter. They also need to be free of competition from grass growing around their surface roots, so a good-sized area should be left clear under the tree, which can then be kept covered with an organic mulch to conserve water and protect the roots from heat. The mulch can be scraped aside whenever you are going to apply fertiliser. Don't ever allow the mulch near the trunk, as this can cause fungal problems.
Young plants should not be allowed to fruit for the first two years, as apparently this will severely affect their growth during that time. To produce larger fruit on established trees, it is a good idea to remove some of the young fruit when it is very small, or even take off some of the flowers. Although pruning is not essential (except to remove dead wood), they don't object to pruning and this is one way to reduce the number of fruit on the tree. Pruning can also be used to produce formal effects such as standards or espaliers out of your citrus trees. Very old trees can be severely pruned in spring. Fertilise and mulch after the big prune and it should rejuvenate, even though you may not get fruit the first season afterwards.
There is a dwarf-growing form of the lemonade tree that is suitable for growing in a tub, repotting as it grows until it is finally placed in a decent-sized container. Once the final size of container is reached, repot every three to four years, pruning congested roots that were at the edge of the pot and teasing away tired potting mix then repot with some fresh potting medium. As with citrus planted in the ground, they need regular fertilising and watering. Keep a potted lemonade tree well fed during the warmer months with a granular fertiliser every three to four months and a dose of Seasol every four to six weeks. Put a layer of mulch on top of the pot but keep it away from the trunk. Water regularly but don't overwater (as this will leach our nutrients from the soil). Don't have a saucer under the pot that can collect water, as this may cause root-rot. It seems it is best to keep the canopy of a potted dwarf lemonade tree pruned to the diameter of the pot. Make sure the pot is in a sunny position and protected from strong winds that can dry out the pots and damage the flowers.
There are various pests which attack citrus - not all affect the fruit, but they can distort the foliage. Eco Oil can be applied on a regular basis to control most of the pests, which include citrus leaf miner (prevalent in summer and autumn), the horrid bronze orange bug (which can affect the fruit as well as the foliage), scale and aphids. There are also sticky traps available to hang in the tree to attract the male citrus leaf miner in order to reduce overall population numbers; this pest is particularly active from December through to April. When establishing a new tree, it is important to control citrus leaf miners, as they will severely affect its growth.