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.
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.
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.
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.
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.
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.
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.
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.