How To Grow Tasty Tropical Fruit
Tropical fruit can be grown in a sheltered garden or greenhouse
Growing a taste of the tropics is easier than you think so why not bring a little taste of your holiday to your garden. Although many of them do need a conservatory or greenhouse there are some species which are hardy and some which grow outside in summer and are brought indoors in winter. These exotics are usually very expensive in the supermarket so it makes economic sense to grow your own. They are probably easier to grow in the south of the UK where there are milder winters and hotter summers.
Apricots, Nectarines and Peaches
This group of fruit trees are all from the Prunus family and need warm sunny conditions. In Victorian gardens they were grown against a wall into which fireplaces and chimneys were set; when the fire was lit the whole wall was warmed and therefore protected the trees against the frost. If you live in the north of the UK these fruits will probably perform more reliably if grown under cover; although recent breeding in Canada has produced some hardier varieties. The apricot ‘Flavorcot’ is one of the Canadian cultivars which is fairly hardy and ‘Aprigold’ is suitable for a container, only reaching a height of 1.2 – 1.5m (4 – 5’) after 10 years. The nectarine ‘Lord Napier’ is one of the tastiest but unfortunately needs protection as it is early to flower and fruit. The peach ‘Rochester’ is one which flowers later so is therefore more likely to be pollinated and escape any frost damage; ‘Golden Lady’ is a good variety for a container as it only reaches 120 – 150cm (4 – 5’), but unfortunately yields are fairly low.
They need a warm, sunny sheltered site, preferably fan trained against a wall either facing south or west. Free-standing trees can be grown in the warmer southern counties. Dig a large, deep hole and add more compost, well-rotted farm manure and bone meal. They need a light, free-draining yet moisture retentive soil. Plant to the same depth as it is in the pot. Make sure you plant at least 20cm (8”) away from the base of the wall, as this is in the rain-shadow and won’t receive enough moisture. If you are growing them in the greenhouse they will still need a good deep root run. Growing under glass also gives protection against the fungus which causes peach leaf curl; although they leaf up again after they have dropped their leaves the plant remains in a weakened state and yield can be affected. If you are growing a tree in a container make sure it has good drainage and that the holes are covered with a piece of broken crock to ensure they don’t block with silt. Use John Innes No 3 compost.
Keep it well watered for the first spring and summer after planting as they are very thirsty plants. Even mature plants will need watering if there is a dry spell. Under glass they are especially thirsty so must be watered regularly. Watering the path to keep the atmosphere humid will also deter red spider mite. They prefer a slightly alkaline soil so if you have acid soil, apply a dressing of lime in autumn. In late February apply a dressing of Growmore at the rate of 70g per square metre (2oz per square yard). Mulch with well-rotted farm manure in March/April. Feed with a high potash fertiliser, such as Tomorite, weekly throughout summer. They are all self-fertile but many flower early in the season when there are few pollinating insects around; in this case you will have to hand pollinate with a small soft brush. Flowers may have to be protected with fleece if there is frost forecast; if this is the case remove it during the day to enable pollinators to gain access.
Citrus –Grapefruit, Kumquat, Lemon, Lime, Orange
See the blog article ‘ Scintillating Citrus’.
Image: Dick Culbert
Guava – Chilean (Myrtus ugni)
This delicious berry was a favourite of Queen Victoria and was grown commercially in the Victorian era, but fell out of favour and has only recently been revived. It is a native of southern Chile and is related to the blueberry but tastes like a cross between wild strawberries and pink guava with a hint of candy floss! This description is courtesy of James Wong. You may find them in the supermarket marketed under the name of ‘New Zealand Cranberries’ or ‘Tazziberries’. Aside from its edible value it is a valuable ornamental garden plant, having glossy evergreen leaves and deliciously scented pale pink flowers. They are delicious made into jam or jelly, eaten fresh or in cakes and puddings.
It needs moisture retentive, well-drained ericaceous compost in a sunny sheltered position; south facing is best as the more sun the plant receives the sweeter the fruit. Incorporate plenty of organic matter into the soil when planting; it needs to be kept damp as it will drop the fruit if it gets too dry. It is not totally hardy only down to -10C (14F), unless you live in a frost free area it is recommended that you grow it in a large container, at least 30cm (12”) in diameter.
Make sure it is kept well watered. It is slow growing but can eventually reach 3m (10’) in height; just trim it to keep to a manageable size. Pruning is not necessary unless it is to keep it in shape. It is self-fertile but, like blueberries, you will get a heavier crop if there are two plants. You will need to bring it into a frost free environment in winter unless it is in an extremely well sheltered position. The variety ‘Villarica Strawberry’ is hardier than others and ‘Ka Pow’ from Suttons is a good large fruited variety. Harvest the small cranberry-sized red berries in late autumn/early winter.
Image: Didier Descouens
Guava – Pineapple (Acca or Feijoa sellowiana)
The Pineapple Guava is an evergreen shrub native to South America and therefore needs a tropical environment to perform to its best. Unfortunately it can take several years for it to fruit and it needs a long hot summer in order for the fruit to ripen. The fruit can be used in jam, smoothies, ice-cream or eaten raw and the flowers are also edible making a lovely addition to fruit salad or as a garnish for cocktails. Given the ideal conditions it will grow to a height of 7m (23’) but it can be pruned to maintain a manageable height of 1.8m (6’). Even if it does not fruit it makes a handsome garden shrub which attracts a range of pollinating insects.
They are not hardy but will tolerate temperatures as low as -12C (10F). They need a sunny, sheltered south or west facing wall but will appreciate a little light shade. They need a well-draining moisture retentive soil that must be kept damp. When it is mature it is tolerant of drying out occasionally and salt winds, but when young it must be protected from strong winds as the leaves will burn.
Water regularly during the growing season and give it just enough water in winter to prevent it drying out. It must be protected from frost so it is only recommended for growing outside in a frost free climate; in the north of the UK it would be better grown in a conservatory in a large tub, such as a half barrel. It produces an egg-sized fruit which often falls to the ground when ripe. To test if it is ripe on the tree squeeze gently and if it yields a little then it is ripe.
Inca Berries (Physalis peruviana)
These sweet sticky little berries taste like a cross between pineapple and kiwi and were grown widely in Victorian gardens. They are related to the tomato but without the threat of blight hanging over their heads. They are absolutely loved by the bees so are a good plant to attract pollinators into your garden. They are really easy to grow; being disease and pest resistant and they are even tolerant of a little neglect if you forget to water them. They are full of pectin so are great for making jam. They keep fresh in the fridge for up to 3 months after picking and also make tasty pies, sorbets, crumbles, fruit salad and garnish for cocktails.
Sow the seed in February - April a half inch deep in good quality peat-free seed compost. Place in a tray of water for 10 – 15 minutes until the compost is damp then place them on a sunny windowsill or in a propagator at a temperature of 15 – 18C (60 – 65F). Germination can take from 20 -40 days.
Once the seedlings have formed 2 pairs of leaves prick them out into 9cm (3”) pots into good quality peat-free potting-on compost. Keep them somewhere frost free until it is safe to plant them outside after the threat of frost has passed.
Plant them out in a warm, sheltered, sunny position in moisture-retentive well-draining soil. If you are planting them in a growbag just plant one per bag or plant in a large pot, at least 30cm (12”) in diameter, in good quality peat-free multi-purpose compost.
Although they are drought tolerant they perform best if they are kept damp. They should produce a crop 20 – 24 weeks after sowing in late summer - early autumn. If you live in a frost-free area or only receive a couple of degrees of frost just cover with a thick mulch of compost in winter. If you are likely to have a harsh winter just pot up and bring into a frost free greenhouse or porch over winter.
Kiwis - Cocktail (Actinidia arguta)
There are about 90 species of kiwi and this is a smaller, sweeter, hairless version of the large kiwi found in supermarkets. It can take 2 – 3 years to bear fruit but an established plant, about 5 years old, can produce up to 400 fruits. As this is from Siberia it can tolerate temperatures down to -35C (-31F) so it is fully hardy here in the UK. It is a vigorous climber so needs to be pruned to restrict its growth and encourage fruiting. The variety ‘Issai’ is self-fertile but any other variety must have a male and female plant, planted about 150cm (5‘) apart. It can be eaten raw, skin and all, or made into fruit salads or fruit puddings.
It ideally needs a sunny, sheltered wall with strong wires horizontally spaced 30cm (12”) apart. If growing in the centre of the garden put in strong posts to support the wires. It needs moisture retentive but well-draining soil; fork in some well-rotted farm manure and garden compost plus Growmore balanced fertiliser at a rate of 70g per square metre (2oz per square yard).
Make sure that it is kept well watered in any dry period. It fruits on wood which is a year old or older so the new seasons vigorous growth must be kept pruned back to about 10cm (4”); this ensures the fruits receive maximum sunlight. A mature plant can produce up to 20kg (44lbs) of fruit. Although it is hardy it may be necessary to cover the flowers with fleece in spring if there is a frost forecast.
These fruits are a member of the same family as cucumbers, courgettes and gourds. They originated in Africa and tropical Asia so will need to be grown in a greenhouse or polytunnel as they need a warm, sunny environment with high humidity. Which? Gardening ascertains that the best melons for growing in the UK are ‘Alvaro’ and ‘Magenta’.
Sow one seed, on edge, in a 9cm (3”) pot into good quality peat-free seed compost. Keep it in a warm environment and the compost damp.
They really need to be planted in a bed as they have quite a voracious appetite for food and water. Three to four weeks before planting dig the bed well and incorporate plenty of organic matter, making sure any farm manure is well rotted. Also add some granular balanced fertiliser. They need a rich, fertile, deep soil which is well-draining but moisture retentive. Water the bed well and cover with polythene to warm up the soil prior to planting. Plant them at least 60cm (2’) apart.
When they have formed 5 leaves pinch out the growing tip to encourage it to send out side shoots; keep the 4 strongest side shoots and pinch out all the others. Once the first fruit has formed, feed weekly with high potash fertiliser, such as Tomorite. There is no need to pollinate by hand just make sure there is plenty of ventilation and plant some marigolds to encourage the pollinators. Just allow 4 fruits to develop on each stem, take off any subsequent fruit and pinch out the growing tip and any side shoots. Keep them well watered. Watering the path and keeping the atmosphere in the greenhouse humid will discourage red spider mite and mildew. The greenhouse will need shading if the temperature reaches 25C (77F). Place the fruits on a tile to prevent them rotting. Once the fruits have started to ripen and the foliage is dying back stop feeding and reduce the watering. They are ripe and ready to eat when they have that characteristic melon smell.
Olive (Olea europaea)
See the blog article: ‘How do I grow an Olive tree (Olea europaea) in a pot or container?’.
Pomegranate (Punica granatum)
It is thought that they could have originated in the Middle East where they have been in cultivation for at least 5,000 years. It is worth growing for its beautiful red flowers alone. It is one of the few fruits which you can harvest in winter as it flowers from June - August and starts fruiting in October; it does however need a mild autumn. It is half-hardy withstanding temperatures down to -15C (5F), so can be grown outdoors in a sheltered frost free environment. Self-fertile ‘Provence’ trees are available from Thompson and Morgan. It can eventually reach a height of 3m (10’) and a spread of 1.5m (5’), but it can be contained by pruning. They can take up to 3 years to produce a crop and up to 6 years before they give a maximum yield. Harvest the fruit when the crown at the base of the fruit has started to curl and gone brown.
It needs a sheltered spot in full sun with rich, fertile, well-draining soil. Dig in a little horticultural grit to ensure good drainage. If you live in an area with cold winters it may be better to grow it in a large container and move it into a frost free environment over winter. Make sure the container has adequate drainage holes; avoid the holes silting up by covering them with a piece of broken crock. Fill the container with John Innes No 3 mixed with a little horticultural grit to improve drainage.
Keep it well watered in the growing season. Give it a mulch of well-rotted manure or compost in spring. Feed with balanced fertiliser in spring and a high potash feed, such as Tomorite, in mid – late summer. If it is planted outside protect the roots in winter with mulch and wrap the plant in fleece if there is harsh weather forecast.
Grow it as a multi-stemmed specimen with a basic framework of 3 – 4 strong stems. These stems need shortening by a third in spring for the first 3 years. Keep the centre clear to ensure a good airflow through the plant. In subsequent years only prune if absolutely necessary as excessive pruning will reduce the crop yield. Remove any suckers which form at the base.
Image: C T Johansson
Tamarillo – Tree Tomato (Solanum betaceum; Cyphomandra betacea)
This Tree Tomato originates in the Andes of South America but is now widely cultivated in many sub-tropical climates. It is fairly fast growing to a height of 4m (12’) and has a life expectancy of about 12 years, but does not usually fruit until it is 4 years old. It is loved by bees and other pollinators. It is high in vitamins and iron but low in calories. As it needs a minimum winter temperature of 15C (60F), it is best grown indoors in a large pot; at least half a barrel size. The fruits can be used for jams, ice-cream, sorbets, pies and desserts.
Sow one seed per 9cm (3”) pot in good quality peat-free seed compost. Stand the pots in a tray of water until the compost is damp, it is important that you don’t let them dry out. Keep at a temperature of 25.5C (78F) and they should germinate in 3 – 5 weeks. Gradually increase the pot size, using John Innes No 2 compost until it is in its final planting position.
Make sure there are sufficient drainage holes in the container and cover them with a piece of broken crock to stop them blocking with silt. Fill the tub with good quality peat-free compost mixed with a little horticultural grit to improve the drainage and a couple of forks of well-rotted farm manure.
Make sure it is kept well watered as it will not tolerate being dry. If it gets out of hand it can be severely pruned, but will respond well to being kept at a height of 1.8m (6’). They are self-fertile but production will increase if the flowers are pollinated. The fruits are egg-shaped and can vary in colour depending upon variety, from yellow to red, and measure from 4 – 10cm long. They fruit in late autumn into winter and when mature one plant can produce hundreds of fruits which ripen over several weeks. When they are ripe they sometimes drop from the plant.
Watermelon (Citrullus lanatus)
It is possible to grow watermelons in the UK provided you have a sunny, sheltered site outside, a greenhouse or polytunnel. The recommended varieties are: ‘Charleston Grey’, which is an elongated fruit with orange/pink flesh and ‘Small Shining Light’, which originates in Russia and can grow to the size of a football. It is an excellent attractor of pollinating insects.
Sow a single seed on edge in a 9cm (3”) pot from February – April in good quality peat-free seed compost; push it just below the surface. It needs a temperature of 24C (74F) to germinate; once the leaves appear reduce the temperature to 18 – 21C (65 – 70F). Keep the compost damp.
It needs quite a lot of space as it will spread at least 1.5m (5’). Plant in a heated greenhouse in late March; late May if the greenhouse is unheated and late June if planting outside. They are best planted in open ground or a bed in the greenhouse, but they will grow if planted one plant to a growbag or large pot, at least 30cm (12”) in diameter. It needs well-draining moisture retentive soil with organic matter and granular balanced fertiliser incorporated.
Keep them well watered by watering the soil not the foliage. When the first fruits start to form feed with high potash fertiliser, such as Tomorite. Rest the fruits on a bed of straw to keep them clean and deter slugs. The fruits are ripe when they sound hollow when tapped.