What could be better than picking a fresh lemon or lime for your G & T and accompanying it with some home grown Olives? Or perhaps a fresh grapefruit for breakfast?
Citrus and Olive trees are just two 'exotics' that will grow and thrive in your garden during the Summer months, just needing protection from the worst of our British Winters. Other so called exotics such as Passion Fruits, Pomegranates, Loquats and Fruit Salad Trees will actually prove hardy throughout the year in all but the most Northern UK gardens.
Don't be put off that these subjects will be particularly difficult or hard to grow - they're not! Our exotic fruit aftercare instructions will point you in the right direction. For those considering growing Citrus, Simon Lindley's recent article in Grow It magazine Oranges Are Not The Only Fruit is a must to read.
General Guidance & Advice For Exotic Fruits
Container Growing
All the exotics we list can be grown in patio tubs or containers. If planting in a patio tub or container choose one of a good size for the subject you are growing. Small containers with a plant loaded with foliage and fruit could become top heavy in high winds such as we have experienced in the U.K. over the last few years. The ideal container, if for a patio, is either one made of concrete or a half-cut wooden barrel or tub. We have yet to find a plastic container that does not crack or break down after 7 or 8 years. If planting in a tub good drainage is essential. Holes should be made in the base, and possibly in the sides at the base as well. Avoid standing the container where it will become waterlogged. Ideally the container should be stood on a couple of house bricks or gravel to assist drainage. Ordinary garden soil suits most fruiting stock so there is no need to purchase expensive composts from garden centres (though Citrus tend to be acid lovers so will need an ericaceous soil or compost). A little brick mortar rubble in the bottom of the container to cover the drainage holes and to stop the soil falling through is recommended. At planting time do not introduce any stimulants, fertiliser or bonemeal. This can prove positively injurious and harmful.
Planting Out
Despite being described as ‘exotic’ many of our exotic subjects are in fact UK Winter hardy and so suitable for planting outside in the open ground – please check the more specific notes below. As with many things in life, remember that a little extra care and time taken with planting out will pay dividends for many years to come! Dig a hole approximately double the width and double the depth of the size of the plants container it was grown in. Now fork over the sides and bottom of the hole to loosen up the surrounding soil before refilling to bring the soil level up to the correct planting depth for your plant; you can either refill with the soil you originally dug out or ideally with a mixture of this soil and 25% organic matter such as well rotted manure (not fresh) or compost to give your plant the best start.
Place the plant in the hole, ensuring its final planting depth is the same or only slightly deeper than it had been previously grown at (indicated by the soil or compost mark on the stem). Now refill, either with the previously removed garden soil or your soil / compost mixture. Firm in well and water if soil is dry. Under no circumstances should you use any stimulants, fertiliser or bonemeal at planting time as such products will ‘burn’ any new root growth and actually slow your plant’s development!
In the first growing season after planting it is vital to ensure the plant is adequately watered - and this is even more critical in extended dry periods or drought. When watering any newly planted stock a ‘heavy soaking’ once a week is favourable to a ‘light shower’ every day, and will encourage a good deep root system.
Keep the area around the base of your plant free of weeds and grass which would otherwise compete for both moisture and nutrients. To further aid moisture retention it is a good idea to mulch around your newly planted plant with chipped bark, well rotted manure or similar; this will also help with suppressing weed growth.
During the active growing season an occasional feed with our ‘Instant Life’ or a light top dress with a base fertiliser will prove beneficial. Under no circumstances be tempted to overfeed though!
Pruning & Training
Many many books have been written on fruit pruning and training – a subject we cannot detail on this simple guidance sheet; to this end, for guidance on training and pruning we would recommend the book ‘Success With Organic Fruit’ available from ourselves.
Some additional notes on specific varieties...
Chinese Loquats
These can be grown outside in a South West position. They do produce olive sized fruits, after about four years, not unlike the peach in flavour - hence the name the Pseudo Peach. These are frost hardy in our experience but can also be grown in a cold greenhouse or conservatory. They will thrive in ordinary soil. No special pruning required and are in fact best left to grow to full size of around 12ft.
Citrus
These can be grown outside from June to mid September but must come in for the Winter. No special pruning is required. Trim off straggly shoots. Good Winter light is essential but difficult in the UK and inevitably some leaves do yellow and fall; in fact in low temperatures all leaves can drop but will renew with warm Spring sunshine so don’t worry. Ideal Winter temperature is 50°f (10°C). We keep ours at around 40°f (5°C). Once a month break up a couple of spent tea bags and stir into the compost; Citrus like a soil tending to be acidic - rotted oak leaves would have the same effect too. About once a month from November to March add 1 level teaspoonful of Epsom Salts to each Citrus - this will improve leaf colour and general well being. Spray over in Spring with a fine mist spray to assist pollination. If, as can occur, scale insects appear on the undersides of the leaves spray with our BioFriend Plant-Defence or dab these with a paint brush dipped in neat methylated spirits.
Fruit Salad Trees
These originate from Brazil yet can be grown outside in the UK in ordinary soil. Outside fruit is only produced after a very hot Summer but is easily produced in a greenhouse. No special pruning or care is required. Its very attractive white and scarlet flowers are edible and can be crystallised for cake decoration.
Goji Berries
Originating from Tibet and Mongolia, these are extremely hardy and can grow to 8ft – 10ft tall. They will grow in most soil types, but will not tolerate wet soggy soils, and prefer a full sun position. If planting more than one allow 6-8ft apart. Small purple and white trumpet flowers are followed by small oval berries that are red in colour; these can be harvested until the first frosts. It is better to shake the berries from the plant rather than picking by hand as this will cause the fruit to oxidize and become black in colour.
Olive Trees
These should always be grown in containers of well drained ordinary garden soil. They will need Winter frost protection in a greenhouse or conservatory. These are of course native to the Mediterranean climate so a hot baking Summer suits these well. True olives can be produced in the UK given warm sunny growing conditions. No special pruning required - simply trim to shape about once a year. Keep semi dry in Winter.
Passion Fruit
Grow this as an attractive climber over an arbour or similar. A few tendrils can be trained to grow in a greenhouse for early fruit; unless you have a large glasshouse avoid growing completely under glass as the plant would 'swamp it'! Though hardy these may be killed off to ground level in a severe Winter – to re-grow from the roots.
Pomegranates
Considered by many to be frost tender these will actually take mild frosts occasionally. Grow in large containers and move in for the Winter months or grow in a warm sheltered spot in the garden.
a copy of this guidance can be downloaded here - Exotic Fruit Guidance
Oranges Are Not The Only Fruit
Following on from our popular feature on lemons, Simon Lindley takes a look at the range of other marvellous citrus fruits you can grow easily here in the UK
Members of the citrus family – oranges, lemons, limes, grapefruits and so on – are prized for their flavoursome fruits and vitamin C content. In fact, though, they contain no more vitamin C than most other plants, but this notion has stuck around since Georgian times when they were used at sea to ward-off scurvy.
When you think of citrus fruit, oranges and lemons immediately spring to mind. But it’s possible to grow much more than this in the UK. Clementines, mandarins, satsumas, grapefruits, kumquats and limes, as well as bergamot – so you can make your own Earl Grey tea – all do well over here.
Something In Common
All citrus plants can be easily grown in the UK as long as you make sure you provide a frost-free environment in the winter months. Cold, wind and rain combine to make these plants miserable, meaning they need to be brought inside in the autumn. They are tolerant of cold down to around 5ºC, so an unheated polytunnel is the best. Try to keep them in the sunniest places, not necessarily for the heat it brings but because they’ll prefer it.
Just because it’s winter doesn’t mean that citrus plants are going to ‘sleep’. In fact, they actively grow during this period, and most of them flower in the winter too. An orange in flower on Christmas day is a lovely thing!
Citrus Savvy!
Whichever citrus plant you want to grow, they’re easy as long as you follow the rules:
Keep plants cool but frost-free in winter – minimum 5ºC.
Water freely, but ensure good, free-draining.
Feed regularly in the summer, less so in winter.
Prune and re-pot in spring.
Keep the atmosphere humid by watering paths and, if kept inside year-round, ensure good ventilation during hot weather.
Clearly, if they’re to be brought in during the winter, these plants need to be grown in pots. For preference, a large terracotta pot is best because it’s porous and provides an amount of air to the roots. In addition it will more readily allow for the evaporation of water, plus store heat for much longer than a plastic equivalent. As far as size is concerned, a 60cm pot for a small citrus tree will be perfectly adequate.
Fill it with a soil-based compost (John Innes No.2) and incorporate some sand into the mix, say up to 25%. All citrus plants generally need the same regime when it comes to watering and feeding. They don’t like to stand in wet conditions, but do enjoy moisture. However, take care not to over-water; simply make sure the soil is slightly moist, and that the pots are positively free-draining.
Use a good quality general fertiliser (making certain that it has all the necessary trace elements), at least once a month – possibly once a fortnight in the spring. Some people use winter-feed and a separate summer feed. But, as long as you use a good quality, all-round fertiliser, this expense isn’t necessary in my view. Feed less in the winter, just once a month or so.
Propagation
Most citrus plants will grow readily from fresh seed, but will take around a decade to flower and fruit, sometimes two. Plants can be grown by taking hardwood cuttings in the autumn; around half will ‘take’ and, after a couple of years, the trees might produce fruit. All citrus plants bought from garden centres and nurseries are grafted on to specialised rootstocks, and the vigour that this ensure means that they will grow to their full height very quickly. Most plants are propagated by budding; where a single bud is grafted on to a rootstock/scion combination.
Re-Potting & Pruning
This is best done in the spring. Trim your plant just above a fat, lush-looking bud, so the tree takes on a good, roundish shape and remains at the appropriate height for your tunnel.
Re-pot yearly into the next size up. Take the opportunity to add some slow-release fertiliser and fresh, well-draining compost. Gently remove some of the soil and ensure there is plenty of crockery in the bottom of the new pot for drainage. Add new compost/sand mixture and firm well in. Give a good watering, and keep the plant out of draughts/wind for a
few days.
Citrus Vital Statistics
Habit: Small to medium tree. Kumquats are more bushy, clementines and satsumas are smallest tree, 1.5m.
Height: Up to 2m.
Spread: Decided by pruning.
Foliage: Evergreen.
Soil Type: Acidic as low as pH 6.5 (use a soil test each spring).
Position: Sun.
Min. temp 5ºC.
Pruning: In the spring – make a good shape, keep height appropriate for fruit.
Flowering: Winter
Fruit: Ripe in November.
Pests & Problems
All citrus suffer from the same group of pests; aphids, red spider mite and scale insects. A weekly wash with soft soap will keep most of these in check. They drop their leaves regularly in the winter, but should not lose more than a third. Any evidence of yellowing leaves could be due to overwatering, lack of nutrients, low temperatures or insufficient sunlight.
Keep plants well ventilated but out of strong draughts to avoid botrytis and other fungal infections.
Above all, water well but don’t allow them to stand in water.
Oranges
Every navel orange is a descendant of a single mutant tree found in the early nineteenth century in Brazil. It was budded and the small plants sent around the world. They’re very heavy fruit and, consequently, the trees need to be large to take their weight. The fruits are seedless and have a small ‘baby’ fruit inside them.
Blanco oranges are smaller and so can be borne on smaller trees. Most fruits can be harvested from November to December.
Grapefruit
Grapefruit first appeared in the West Indies – another mutation – in 1750, and were transported as buds all around the world. They were particularly prized by rich English landowners who grew them in hot houses, even though they can be dragged outside in the summer. The plants are larger than oranges, and bear larger fruits. Otherwise they can be treated in exactly the same way.
Kumquats
This is a fast-growing tree and the fruits can be eaten whole. They are also supposed to be good pickled in brandy. They grow to be quite large and, for this reason, are kept in a single position.
Clementines & Satsumas
These plants ripen around Christmas, most being ready after November. They can be kept quite small, even though they are vigorous plants. Annual trimming keeps them in check, but you can grow them up a wall or as a large bush.
Limes & Limequats
Limes tend to be easy to grow and can be restricted to a reasonably small tree of about 1.7m high. There are a number of varieties and each grows well in the UK – some turning yellow when ripening. A limequat is a cross between a lime and a kumquat.You can eat the whole fruit, and it tastes like a lime.
This article appeared in the August 2007 edition of Grow It magazine; the full as printed magazine article can be viewed by here - Oranges Are Not The Only Fruit – Grow It August 2007
