Exotic Fruits to Grow in the UK
Kiwi fruit used to be considered easy to grow – and the tree or vine is – but actually getting viable fruit from a plant is a more complex issue. If you have an existing plant, it may be an older variety that isn’t getting enough sunlight. And it will just keep getting bigger and bigger, unless pruned, but pruning can also remove all the fruiting canes, so it’s important to be careful when pruning. Basically the fruit grows on canes that are a year old or older, rather like an overgrown raspberry or a vine. As each year passes, the fruit produced will be proportionally reduced so by year four, the cane is non-productive. This means that it is best to cut canes that are three years old, or older, right back to ground level so that the one and two year old canes have plenty of air and light to fruit on.
The best variety to grow in the UK is Jenny, which is self-fertile but does not produce viable seed, so you must buy a young plant from a nursery. It has been known to fruit, on a white-painted south facing wall, in Yorkshire, so in ideal conditions, with maximum light, it should do well in many gardens south of that. Do not prune a potted kiwi for two years after planting, give lots of compost and mulch and water when planting out. Be careful not to over water which can cause root rot and after two years prune out old canes in February. Do not water in winter unless the ground is extremely dry and give liquid feed monthly from May to September. Fruit will be harvestable from late August to September depending on the region.
Remember that the kiwi fruit, while having almost no pest problems (red spider mite is the only real issue, and that’s for potted plants) can be difficult to harvest: too early and the fruit is bland and hard, too late and it becomes a mushy disaster – getting the level of sugar in the fruits right is out of human control as it requires a warm summer without too much rain … but in the years when it is right, the fruit is very good indeed!
Persimmon/Sharon FruitThis tree really requires patience and fortitude. You need several trees for pollination, and it takes around seven years from planting to bear fruit. It’s not all bad news though: the trees are generally very ornamental and highly regarded in landscaping.
In the early years, the trees must not be allowed to experience temperatures below -10°C although once mature they can tolerate -18°C because they enter a state of winter dormancy. They do need excellent ground drainage though, or they may experience winter root rot. As trees native to China, that thrive in the USA, Pakistan and Israel (where they are called the Sharon Fruit), their main inhibitor in the UK is wet winters which can kill young trees.
When buying a persimmon variety, ask the nursery for an astringent variety as these are more suited to the British climate. The fruit do have to become jellylike before being edible but they will survive better in cool regions than the non-astringent varieties which need drier winters – if the summer is not warm enough, astringent persimmons can remain bitter to the taste but the trees are much more likely to survive through the UK winter than non-astringent varieties. You can harvest the astringent variety fruit while it is unripe and it will ripen in a warm room. The trees need full sun and good air circulation, so do not grow them against a wall.
LoquatThe loquat is an amazing looking tree – it can make six metres in height and four metres in width and has huge heavy leaves, like a horse chestnut but even bigger, a deeper green, more ridged and with much more dramatic incising along the edges. Then there are the flowers: white and with five simple petals but with a very rich and fruity scent.
If you grow a loquat and can plant it at the bottom of a slope, do so, as the flowers grow at the top of the tree and therefore much of the scent is lost to the atmosphere. While it’s entirely winter hardy up to the Scottish borders, the fruit of the loquat has only ripened widely across the UK infrequently: 1976 and 2010 were both years when the warm summer and long dry autumn allowed the tree to create ripened fruit. And while the tree itself will thrive through the winter, it will drop its leaves and the branches will blacken in a very cold season, and that means it can look rather bad for some months of the year in colder climates, although the loquats in South London, Cornwall and even South Wales, seem to avoid even this winter blackening.
If you buy a tree, be aware that it has a long and very brittle tap-root. Transplanting can be difficult because if you break the root the tree will not thrive. The temperature below which a flower bud will not set fruit is 7º C which makes growing this as a fruiting tree a real gamble – but a gamble that has highly ornamental benefits.