The Kiwi Plant: How To Grow Young Vines As A Source Of Delicious Garden Fruit
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
IN THIS GUIDE
Matching the rise in popularity of the Kiwi fruit over the past few decades is the recent ascendancy of Kiwi as a garden plant.
These come in a surprising array of fruiting vines which can be grown from coast to coast in the UK.
Admittedly, maintaining Kiwi vines requires time and skill but think of the reward: a bounty of garden-grown luscious Kiwis.
Kiwis are often thought of as a fruit native to New Zealand; an exotic fruit with not very many types.
These are both misconceptions.
The types of Kiwis that we commonly buy at the store are native to China and were introduced to New Zealand as late as 1904.1Chinese gooseberry becomes kiwifruit. (1959, June 15). New Zealand History Online. Retrieved March 20, 2023, from https://nzhistory.govt.nz/the-chinese-gooseberry-becomes-the-kiwifruit
It is not exotic as so many hybrids and cultivars exist that they can be grown in hardiness zones from H3 through to H7.
The fuzzy-skinned green Kiwi that we know and love so well is Actinidia deliciosa.
It originates in the southeastern coastal regions of China.2Actinidia chinensis var. deliciosa. (n.d.). Kew Royal Botanic Gardens. Retrieved March 20, 2023, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60458895-2
Overview
| Botanical Name | Actinidia |
| Common Name(s) | Kiwi |
| Plant Type | Fruit / Climber |
| Native Area | China |
| Hardiness Rating | H3-H7 |
| Foliage | Deciduous |
| Flowers | Creamy white flowers |
| When To Sow | March, April, May |
| Flowering Months | June |
| Harvesting Months | August, September |
| When To Prune | January, February, July |
Sunlight
Preferred
Full Sun
Exposure
Sheltered
Size
Height
8 – 12M
Spread
2.5 – 4M
Bloom Time
June / July
Soil
Preferred
Loam, sand
Moisture
Well drained
pH
Any
The Actinidia genus contains about 60 species, plus many hybrids and cultivars of the prime fruiting species.3Mahr, S. (n.d.-d). Kiwi fruit. Wisconsin Horticulture. Retrieved March 20, 2023, from https://hort.extension.wisc.edu/articles/kiwifruit-actinidia-spp/
Comprising of shrubs and vines, all of them bear fruit from the size of a large grape to the relatively large fuzzy Kiwi.
The vines that bear the smaller fruit are hardy – some are very hardy – and these are native to north-eastern Russia.
Growing Considerations
The ‘Fuzzy Kiwi’ fruit that most of us are familiar with is that of the ‘tender Kiwi,’ usually Actinidia deliciosa, sometimes Actinidia chinensis.
Kiwi vines are traditionally dioecious – they bear either male or female flowers.4Gao, G., Slaughter, R., & Sherman, B. (2020, May 28). Kiwifruit and Hardy Kiwi (Kiwiberries). Ohioline. Retrieved March 20, 2023, from https://ohioline.osu.edu/factsheet/hyg-1426
Only the female vines bear fruit whereas male vines are necessary for pollination.
The vast majority of commercial-named cultivars are either male or female though a few occur in both male and female forms, though during the past couple of decades, some reliable monoecious self-fertile cultivars have been developed.
Flowers are white or creamy with the male ones having very prominent yellow anthers. They are more or less bowl-shaped with a full look about them.
All kiwi flowers are pleasantly fragrant with the sweetness and intensity of the fragrance varying by variety.
Habitat & Growing Conditions
The various species of Actinidia are native to a swath of land from India and the Himalayas arcing south-east to steamy Borneo and north-east to cold Manchuria and frigid Khabarovsk.
As one might expect, these different species’ respective hardinesses span many zones.
The genus includes frost-tender species that are good for RHS H3 areas (USDA Zone 8) through ‘super-hardy’ vines that are hardy right down to RHS H7 (USDA Zone 3).
The species of paramount interest to us, A. deliciosa, grows wild in the south-eastern coast of China’s Zhejiang province in scrubland with soil of varying quality and where these plants are frequently exposed to stiff northeasterly winds.
A. deliciosa (common kiwifruit) is hardy throughout most of the UK (RHS Zone H4).
How To Grow Kiwis
A few of the more popular cultivars like ‘Hayward’ and ‘Jenny’ can be found as potted plants at some of the bigger nurseries and garden centres.
A more extensive selection of cultivars is available at a limited number of fruit tree specialists.
These merchants are easily found online and they are your best bet for obtaining a quality vine.
Young vines are supplied as potted plants and in bare root form.
In addition, you can ‘get’ Kiwi vines yourself by propagating them from softwood cuttings – mid-spring is the ideal time to do so.
Be aware: our plant care guidelines pertain to tender Kiwi vine varieties which are derived from A. deliciosa.
You can grow these outdoors in most regions of the United Kingdom but if you live in the Scottish Highlands or a particularly cold region of northern England, you will have less trouble with a hardy Kiwi cultivar, unless you grow tender Kiwi vines in a greenhouse (though if you use traditional dioecious vines, fertilising the flowers will be a problematic chore).
Soil Requirements
In growing Kiwis, soil pH is not of much importance while other soil-related factors are of great importance.
That said, the optimal soil pH is moderately acidic to slightly acidic; between pH 5.6 and 6.5.
The soil should be laid deep and drain very well.
It should be a sand-based, light, friable loam which should include chalk and may also be amended with compost but should have minimal or no clay.
As any waterlogging is very detrimental to these vines, to ensure good drainage the ground may be worked into mounds or ridges into which Kiwi vines can be planted.
Feeding
You may work in just a little bonemeal, fishmeal, or both into the soil itself; do not ‘fertilise’ the roots with it.
It will act as a slow-release fertiliser high in Phosphorous and Potassium.
Exposure
The site should be where the plants are sheltered but enjoy full sun.
Ideally the vine should be positioned against a wall that shelters it from the north-east and leaves it with a south-westerly exposure.
Spring frosts slow both flowering and fruiting.
The vine can tolerate a frost of up to about -7°C; anything colder and it will likely suffer adverse effects.
Vines are best planted out in early spring, two to four weeks after the last frost.
Pollination
If you intend to grow your Kiwis the traditional way with dioecious vines, go with one male vine and four or five female ones.
These should be sited close to one another: ‘Atlas’ and ‘Hayward’ are the cultivars of choice.
If you want to use a monoecious vine, which is a godsend if you have limited space or must grow your vine in a greenhouse where pollination will be next to impossible, ‘Jenny’ is a top choice for the UK; ‘Solissimo’ is an excellent alternative.
Depending on the varieties and other variables, it takes two to five years, typically three, for vines to produce fruit.
Watering
Water regularly so that the soil is kept moist – it should not stay wet.
Vines have increased water requirements soon after transplanting, when they are young, and when they are setting fruit.
In wet parts of the country, established Kiwi vines may well get enough water from the rain.
Support
Female vines have to be grown and trained on trellises (though one ought to do so for male vines too).
A-frame pergolas are even better as the vine is trained and opened on it in such a way that yields are boosted and harvesting is easier.
Pruning
For good yields the female vines – besides being adequately pollinated – need to be trained and correctly pruned.
“My experience of kiwis (the vigorous cultivar ‘Jenny’) is that if they aren’t pruned annually, they will make a bid to take over your garden,” warns Horticulturist Colin Skelly.
“When trained, they are an ornamental feature in their own right as well as a source of delicious fruit.”
All said, it is a technical gardening endeavour that requires time and commitment.
Train and prune each vine initially so that there is a single leader and about four arms or canes. (These will be refreshed about every three years.)
- When the leader gets to the top of the frame, pinch it to halt further growth.
- You should then have three or four strong lateral arms initially – these will become the first fruiting arms.
- Train these arms at an angle on the trellis and prune any new shoots.
The aim is to have a single leader, and to maintain fruiting arms that are spaced from 50-70cm apart on the vine.
The arms that are one or two years old bear the most fruit; arms bear less fruit as they age.
In summers, deadhead spent flowers and thin them if the bloom is excessive.
Train new shoots on the trellis to grow above and away from foliage so that they get the right start.
In winters, prune the fruiting arms judiciously – prune arms that are three or more years old (provided you have a sufficient number of young fruiting arms).
Maintain the correct spacing between these fruiting arms, and prune excess new shoots. Strive to keep a good balance of new shoots and one- and two-year arms.
At this time, train the arms to grow above and away from the foliage.
Overwintering
Water the vine only now and then in winter.
In winter keep an eye on the weather forecast.
If a prolonged freeze or repeated frosts are expected, protect the main vine and leader right from the soil line with horticultural fleece.
Feeding
Every alternate year, you may mix in a touch of bonemeal, fishmeal, or both into the soil away from the roots each spring and then fertilise with nitrogen, or annually apply a little 10-10-10 slow-release fertiliser.
Avoid using ‘regular’ fertiliser on Kiwi vines.
Harvesting Kiwis
As the flowers form into fruit – fruit set – and thereafter until the fruits are harvested, increased watering is beneficial.
At this time the vine may be watered every other day.
If you see an abundant setting of fruit or even abundant flowering (on the female vines, not the male vine), some thinning may be a good idea to ensure that the fruits you harvest are of the highest quality.
Such thinning is dictated to a great extent by the cultivar; for example, ‘Hayward’ will benefit from it but ‘Issai’ will usually not need it.
Where Kiwi in the UK is concerned, the best plan is to leave the fruit on the vine to mature (unless slugs or birds force your hand) through the autumn, aiming to pick it as late as possible.
When the first ‘real’ frost is forecast, collect all the fruit.
Kiwis will keep indefinitely in the fridge.
If you have to ripen them, place them in a sunny spot in the kitchen or tightly wrap them in two or three layers of newspaper or cotton cloth.
I would personally argue that Actinidia deliciosa – ‘Fuzzy Kiwi’ – eaten peeled and raw, is most enjoyable when the fruit (when pressed from around the peduncle attachment) does not feel at all soft, feels firm-to-hard, with about the firmness (or hardness) of a softwood branch.
The flesh of such a fruit that feels raw to hand pressure will not only be just-ripe but will have a very appealing consistency that is not overly-soft or mushy but will have a bit of ‘bite’, and will be bursting with flavour – sweet, tart, and tangy all at once.
Common Problems
Kiwi plants are remarkably free of pests and diseases in the United Kingdom.
If your garden or ground has any history of honey fungus, then you should avoid growing Kiwi as it is very susceptible to this dreadful plant disease.
Other than that, the only real threat, such as it is, is from slugs.
Even this will be precluded if your vine is on a sun-soaked wall or a type of trellis which cannot be navigated by these nuisance pests.
Common Varieties
Believe it or not, there are dozens of Kiwi varieties. In this section we present some of the most popular:
A. deliciosa ‘Hayward’
A female vine that may just as well be called ‘Old Reliable’.
The Kiwis that most of us have eaten and enjoyed are from this tried-and-trusted cultivar.
It is by far the most abundant Kiwi cultivar in New Zealand and Italy’s plantations and is the only one used by California producers.
It is not particularly high-yielding but the fruit is of top quality.
The hen’s egg-sized fruit has green flesh that is sweet, tart, and tangy.
You will need multiple ‘Hayward’ vines with one male vine to reap a good harvest of fruit.
A. deliciosa ‘Bruno’
Has quite a misleading name, for this is a female vine.
The fruit is of a dark brown colour and its ‘fuzz’ is a little bristlier than the fruits of ‘Hayward’.
Compared to other female vines it is late to flower and, therefore, to fruit.
While the fruit is of excellent quality this vine is also valued for being especially prolific.
A. deliciosa ‘Jenny’
Renowned as a very robust climber that has particularly pretty foliage and even stems.
This frost-tender vine produces fruits about the size of small eggs in mid-autumn.
It is especially easy to grow as a compact, self-fertile cultivar that has proven itself.
For a self-fertile vine it is comparatively high-yielding.
Also, the fruit is of excellent quality as the flesh has a wonderful consistency and is on the sweet side.
A. deliciosa ‘Atlas’
Considered to be the male cultivar of choice.
It is a vigorous climber and produces blossoms through the summer.
These creamy flowers display prominent golden-yellow stamens whose strong, sweet scent attracts bees and butterflies in droves.
It pollinates all female A. deliciosa varieties.
A. arguta ‘Issai’
For those UK residents who want to grow Kiwis but whose location makes growing traditional Fuzzy Kiwis a fraught undertaking.
On the other hand, even if you live in Cornwall you may want to grow ‘Issai’ simply because you prefer the smaller, sweeter, non-fuzzy fruit of Hardy Kiwis.
Be that as it may, this cultivar is so super-hardy that it can be grown in Norway.
It is a very high-yielding vine, producing nearly a thousand fruits per season.
On top of that, this is a self-fertile variety.
