Seven Tips for Growing Citrus Trees

Citrus fruits are some of the most versatile crops for use in the kitchen. They can be juiced for drinks or salad dressings, added to fruit salads, segmented over breakfast cereals, cooked with meat (duck a l’orange, anyone?) and used in any number of cakes, sorbets ice creams, cakes and other sweet desserts. They are also very nutritious fruits, being high in a range of vitamins. Sometimes, however, gardeners can be put off planting citrus fruits on their plot, feeling perhaps that they can only thrive in tropical climates or in greenhouses.

In fact, growing most varieties of citrus is relatively simple, as long as you are able to give them plenty of sunshine. Indeed, that primary consideration aside, permaculture gardeners should be able to cultivate a citrus tree, even if they have limited space. There are lots of varieties available, but some are more suited to small-scale cultivation than others. The Emperor mandarin is easy to cultivate and produces sweet fruit; Valencia is probably the best orange variety as it is hardier than many other species and produces a crop over a longer period; Meyer lemons can be grown in small spaces, and do well in pots; while Tahiti limes are ideal as they produce a lot of juice.

Whichever type of citrus you choose to cultivate, here are some guidelines to help get you started.

Position
Exposure to sunshine is the key to successful cultivation of all citrus varieties. A minimum of five hours full sun is necessary, but the more you can give them the better, so a north-facing position is best. In more temperate climates, it is a good idea to locate the trees next to a wall so that they can benefit from the radiated heat. This will also help to protect the trees from strong winds. A sheltered spot prevents damage to the tree from winds, but be advised that you want to ensure some airflow around the trees, which helps them transpire.

Soil
Citrus trees prefer a soil that has a neutral pH or is slightly acidic. If your soil is alkaline, that best method of lowering the pH is composting well with organic compost. It is even better if your compost contains animals manure, so if you keep chickens as livestock on your permaculture plot, citrus trees should thrive with regular doses of their composted droppings. This will also provide the trees with plenty of nitrogen, essential for their growth and development of a healthy crop, and keep grass away from the tree (which would compete for nutrients and water). It will also assist in keeping the soil well drained, which is essential for successful cultivation of citrus trees.

Planting
When you plant a citrus tree, dig a hole that is twice as wide as the pot the tree is in, and around one and half times as deep. Mix some of the soil removed from the hole with compost (preferably one with animal manure in it) and add to the base of the hole (if you are in an area with heavy clay soil, it is also a good idea to mix in some sand at this stage to help improve moisture drainage). Place the tree in and fill the hole with soil. Water well. Plant your trees in spring after any risk of frost has passed. They need a full growing season to help them establish themselves in the permaculture plot before the winter comes.

Mulch
The roots of citrus trees are comparatively shallow, so they benefit from an organic mulch to provide a slow release of nutrients into the soil (as they do not have the root depth to bring nutrients up from lower down in the soil profile). As with other trees, avoid mulching directly against the trunk of the citrus tree. Adding compost regularly around the drip line of the tree will also help provide it with the nutrients it needs.

Water
Young trees need a lot of watering, and should be irrigated once or twice a week for the first six weeks after planting to help them get established. The ground should be well drained to prevent root rot. Water early in the morning or late in the evening to give the plants the most chance to access and utilize the moisture.

Pots
Even if you have limited space, perhaps just a courtyard or sheltered balcony, you can still grow a citrus tree; it will just have to be in a pot and typically be a dwarf species. The benefit of potted citrus trees is that you can move them around to take advantage of all available sunshine as the sun moves across the sky. You can also bring the trees indoors when cold weather approaches. As you can imagine, potted trees require more constant attention than those in the garden, but the same considerations apply – they need at least five hours of sunshine a day, protection from winds (it is not recommended to have a citrus tree on a balcony high in an apartment block), a decent potting mix that drains well and regular watering. In the warmer months you should be watering once or twice a week as required. Citrus trees grown in pots will need to have their roots trimmed every three years or so. This requires you to take the tree out of the pot and trim approximately five centimeters from around the root ball. Replant with new, well-composted potting mix.

Care
Once established, most citrus trees can survive a winter, unless it involves extremely low temperatures. When the trees are young and an unexpected frost is due, wrap the tree in fleece to protect it (if growing in pots, bring the pots indoors for the night). Citrus trees do not need pruning to help them fruit, but you should take out some leaves and branches if the center becomes too dense, as airflow helps keep the tree healthy. You can prune to keep the tree at a desired size for your available space.

Eight Fruits – A Harvesting Guide

There are few more satisfying activities on the permaculture plot than eating ripe fruit directly from the plant. Plucking a apple from the bough of a tree and crunching into it, standing there in the open air; or easing a pear from its stalk to take back to the kitchen and slice over your breakfast cereal; or getting your fingers stained with the juice of ripe strawberries or raspberries as you harvest the sweet bombs of flavour – these are some of the intensely pleasurable experiences that come with cultivating fruit on your site.

To fully appreciate them – and to ensure they are at their tastiest and most nutritious – it is important to know when fruit is ready to harvest. This avoids picking unripe fruit that is harder to use in the kitchen, or allowing fruit to go overripe and so end up in the compost pile. Here is a guide about the visual and textural clues to look for so you know when various fruits are ripe for the picking.

Cantaloupe
The first sign that a cantaloupe is becoming ready for harvest is that the ‘netting’ that covers the surface will become more pronounced and turn beige from its previous green colour. Also, the blossom end of the fruit should give a little under pressure, and should smell sweet. If you think a fruit is ready to go, give it a little pull; if it is ripe it will come easily away from the stem.

Watermelon
Watermelons have a curly tendril that protrudes from the stem of each fruit-bearing branch. This tendril drying up and turning brown is a signal the fruit is ready for harvest. The other signs that you should harvest the fruit are that the underside that is in contact with the ground will turn yellow or cream in colour, the skin loses its shine and becomes difficult to penetrate with your fingernail, and if you give the melon a tap it will have a resonant sound. Store for a couple of days at room temperature to ripen to optimum taste.

Pear
Pears are actually one of the fruits that it is preferable to harvest a few days before optimum ripeness, allowing them to reach perfection in a bowl indoors and giving you a longer timeframe in which to eat them (if the pear ripens fully on the tree, it will start to spoil within just a day or two of picking). Pears are ready for harvest when the green colour starts to lighten and go yellow. The flesh should still be hard, but if you twist the fruit it should come easily away from the stem. Keep in a bowl in a location between 60 and 70 degrees Fahrenheit and test for ripeness each day. When you press the neck of the pear with your thumb and it gives a little, they are ready to eat. If you want to keep the pears for longer before eating, store in the refrigerator.

Apple
With so many different varieties of apple, it can be tricky to know when your particular variety is ready to harvest. Juvenile apples tend to be green, so if you are cultivating a yellow or red variety, you will see the green change to these mature colours. But, of course, some apples remain green even when mature. So for all apples, the best test is to text how easily the fruit comes off the tree. A ripe fruit will come away easily, with the stem still attached. If a few mature fruits have fallen from the tree, chances are the others are about ready to go. Another check is to open up an apple at the base and check the colour of the flesh – a mature fruit will have paler green colour to its flesh; juveniles are brighter green.

Blueberries
A blueberry is ripe when the fruit is uniformly blue-purple in colour; if you can still see a ring of red around the point where the stem meets the fruit, leave on the plant. If the berry is ripe it should come away in you hand with almost no pressure. A ripe blueberry does not need any pulling to be harvested. In fact, the best way to gather the fruit is to gently roll each one away from the cluster into the palm of your hand.

Peach
Peaches should be left on the tree until they are fully ripe. This will ensure the best flavour and texture, as once picked the fruit starts to deteriorate rather than continuing to ripen in a bowl. When growing peaches have green skin; when these change colour completely, the fruit is mature. The skin will turn a different colour depending on the variety you are cultivating. Yellow-fleshed species will go orange, while those with white flesh will see the skin go yellow-white. Eat soon after picking for the best taste, although peaches can be stored for a day or two in places with high humidity.

Cherries
Cherries keep growing until they are fully mature, so they are ready to be picked when they are plump and almost straining at the skin. You want to ensure that the cherries are at peak ripeness before harvesting, as they do not continue ripening once picked. Sweet cherries will be quite firm to the touch, while sour varieties have a bit more give. Both however should come away from the tree easily when ripe, with the sour varieties detaching from their stems when gently tugged. However, with all varieties, if you wish to keep the fruit for longer than a day, pick with the stems intact. This will extend their prime for two or three more days, especially if stored in the refrigerator.

Strawberries
Pick strawberries that have turned at least three-quarters red. The rest of the fruit will develop this colour after picking if kept in a cool place over the next day or two. Do not harvest fruit that is half, or less, red, as these will not be able to ripen after picking. Harvest early in the morning as the fruit is firmer then and less likely to be damaged during the harvesting process. Keep the stems and ‘caps’ in when you pick.

How to Graft Fruit Trees

Grafting is a technique that allows you to combine a cutting from one tree with the rootstock of another. This can be useful to continue to get a reliable crop of a particular cultivar – for instance, the seed from certain types of apple trees will not go on to be copies of the parent tree so grafting allow you to reproduce from the original cultivar – but also allows you to continue to utilize a vigorous rootstock even when the tree may have lost its production value, and to combine species to produce hybrid fruit. Grafting is also useful as a way of repairing trees that may have been damaged by climatic events such as strong winds or disease, allowing you to replace dead branches that have had to be removed with young, living stems. There are several different methods for grafting fruit trees.

Whip
The whip method of grafting needs the branch to which the graft will be attached and the appendage – called the scion – to be roughly the same size and diameter to work effectively. The branches also need to be quite slender, no more than half an inch across as there is less support for the graft than in other methods. This is why the technique is often used on young apple and pear trees to produce hybrids, rather than on older rootstock. The end of both the branch and the scion are cut at an angle, quite shallow to expose as much surface area as possible, and then the two cut sides are placed face to face. The join is then bound with electrical tape to protect the graft and prevent water and disease entering the wound.

Cleft
The cleft technique of grafting is used to bring vitality back to older, less productive trees whose rootstock remains strong. It is used primarily on apple and pear trees, and can be utilized on the trunks of small trees or the main branches of larger trees. Ideally, you want to use this technique on branches or trunks between two and three inches in diameter, and should not be more than a few feet from the ground or the new tree may grow too large and prove difficult to harvest. Cut off the trunk or the branch with a saw, and then use a hatchet or sharp knife to cut a cleft in the exposed end of the tree limb. Cut the end of the scion into a wedge shape and insert into the cleft. You should not need to cover the graft if the union is tight and secure.

Side
Side grafting sits somewhere between whip and cleft grafts. It is used on trees that are too old for whip grafting but too young and viable to be cut back for bark grafting. Rather than grafting into the cut end of a removed branch, you graft the scion into a cut made into the side of the branch. The cut should be made on a branch at least a foot away from the trunk and should extend no more than halfway across the diameter of the branch. Use a sharp knife rather than a hatchet to retain control over the cut. As above, fashion the end of the scion into a wedge and insert into the cut. If required secure with twine until the graft has taken.

Bark
Bark grafting is typically – like the cleft method – used when an old tree has lost its fruiting vigor. The rootstock is still likely to be robust, however, and grafting young plants onto it can revitalize the tree. It involves sawing off the majority of the tree that is above the ground. You want to take it back to around knee height. Then you use a sharp implement inserted between the bark and the tree on the remaining stump to gently ease the bark away from the underlying wood, creating a gap. The scion – prepared as with the other methods, to have a wedge shape at the end to be inserted – is inserted into this gap, and then the bark is bound tightly to the scion by wrapping either twine or electrical tape around the tree. You may wish to insert two or three scions into the bark and cut back to one when you have determined which has established itself the best on the rootstock. Once a graft has taken, remove the tape or twine so that the tree can grow naturally. Try not to cut the tree back until you are ready to graft – late winter or early spring are the best times for bark grafting – as water can easily get into the tree and potentially spread disease.

Budding
In all the instances above, make sure that the scion you use for the graft has buds on it, as these are essential for fruit forming. Three buds are generally considered a good number for a grafted scion, so that the graft will not depend upon the success of just one. In most cases the best time to graft is in the spring, usually around April or May, when the buds of the scions have set but they have not yet blossomed. There is ne form of grafting that is slightly different.

As the name suggests, this form of grafting focuses on the bud. In fact, it uses just a single bud as the scion, rather than a length of stem or branch. It is often used for fruit trees such as cherry, apricot and plum, which are less amenable to whip and cleft grafting methods. And because you want to use a well-grown bud, it is done in the summer, when the buds have fully developed, rather than the spring. This is also when the bark of the tree to which you are grafting the bud will be at its most pliable. Cut off the bud, leaving about half an inch of stem to hold it by. Cut off any leaves around the bud. Use a knife to cut a ‘T’ shape cut into the bark of the branch you want to graft to, making sure it is at least fifteen inches from the trunk. Slide the ‘handle’ of the bud into the cut and then secure with electrical tape, making sure you leave the bud exposed.