How to Grow Kiwi Fruit
The kiwi fruit originates from New Zealand, as the New Zealand climate is similar to the UK's it should be fairly easy to grow in this country.
Kiwis are easy to grow – it’s getting them to fruit that’s the problem! They’ll grow very large if you let them but this can be controlled with pruning – this will increase their fruiting, but it’s easy to prune out all the fruiting canes, so you have to be careful. Fruit is borne on new growth that appears from canes that are a year or more old. The amount of fruit diminishes every year – the older the cane, the proportionately less fruit it bears. So you should cut out the canes once they are three years old, down to the base. Maintain a healthy number of new, one and two-year old canes and you should have good fruiting.
‘Jenny’ is a self-fertile variety, so any pollination problems are irrelevant. It’s hardier than other varieties too, and will fruit in more temperate climates.You can train the canes (some people call them vines) on a series of wires attached to a southfacing wall.
‘Jenny’ will arrive as a one-year old pot plant, standing around 30cm tall. It will take another two years before it starts producing fruit, and shouldn’t be pruned until then.
Choose a sunny aspect and provide a good rich soil, with plenty of well-rotted compost. Once the plant has been set in its final place, give it a good watering and then leave it for a couple of weeks before assessing the need for another drink. They don’t usually need much watering unless there has been a considerable drought.
After the plant has fruited, prune out the oldest canes, but only one or two, and train the younger ones. Once your plant grows, it will reach a peak of production at around 6-8 years. By this time you’ll have a well-developed regime of pruning and fruiting.
Prune in February, and give the plant a good dressing of well-rotted compost and some organic fertiliser each April. The plant is quite hardy in the winter, just don’t water unless it is showing signs of stress. During the summer, feed with a good liquid fertiliser (I use tomato feed) through the flowering and fruit-setting period, once a month until September.
Kiwi Vital Statistics
Habit: Climbing vine
Height: Up to 10 metres
Spread: Decided by pruning
Soil Type: Well draining
Position: Sun or partial shade
Pruning: In the winter, take out 4 year old canes
Flowering: June to August
Fruit: Ripe from September
Grown From Seed
You can grow kiwis from seed, although not ‘Jenny’. The seeds are sown in compost, moistened and left from November, and will germinate by the spring. The majority of the plants will be male, and you’ll have to wait some time before you can sex them.You only need one of each and they should be planted at least five metres apart.You’ll have to give the pollination a helping hand by taking the pollen and blowing on to the female flowers. In New Zealand they overcrowd the area with honeybees, which don’t like kiwi pollen, but because there is little else available for them, they eventually get round to pollinating the entire crop.
You can take cuttings in the summer from old stems, as long as you include the growing point, and plant them in moist sand or a combination of sand and compost. They’ll strike in the autumn and, by the following spring, can be potted-up as individuals. These can then be allowed to grow for the whole of the following year and then put into their final positions in the following spring. I’ve found that the plant is so vigorous that two plants is one too many!
Some people restrict kiwis in a pot and bring them indoors for the winter. ‘Jenny’ is hardy enough to cope with most British winters, so this isn’t necessary. It’s also possible to prolong the development of the plant under cover, thus inducing it to fruit. In most cases, the self-fertile varieties are more suited to our climate.
Fruits Of Your Labour
The fruit start to appear as small green berries that grow to plum size. They change colour from green to brown once ripe. When this colour change is just underway you can pick them. They are usually hard and take a couple of weeks to soften ready for eating. They will keep almost indefinitely in the fridge, and for a couple of months in the fruit bowl.
If you pick them too early they’ll be tart and have no sweetness, while leaving it too late will likely result in a mushy mess.
The fruit of the self-fertile varieties are on the small size compared to the commercial ones, and they are less hairy. Some people say that if you can cross-pollinate a self-fertile variety the fruits are bigger, but I haven’t found anyone who has actually done it.
There are few problems with kiwis in the UK. They can, if over-watered in poorly-drained soil, get root rot, although this is rare. Similarly, red spider mite can create trouble, particularly in a polytunnel, but this too is uncommon. One of the strangest reported problems I’ve heard is that some cats like them so much they dig and claw at the base of the stems. If anyone has experienced this, and has a photograph, we’d dearly like to see it at the Grow it office!