Citrus - Beautiful evergreen foliage, heavenly fragrance, and spectacular fruit.
Citrus trees look wonderful in containers and they have been grown this way for centuries. Because they are warm climate trees, containers provide the solution to growing them in the coldest climates, where they are moved indoors for winter. Container culture is also a good option if your soil is poorly drained, or if your garden very small.
While any citrus tree can be grown in a pot, the most successful varieties include: Meyer lemon; Tahitian lime, Kaffir lime, Clementine and Satsuma type mandarins, Chinotto, Kumquat, Limequat, and trees grown on dwarfing rootstock, such as 'Flying Dragon'. Orange trees make beautiful container specimens, although ultimately they need a very large pot to fruit well.
Choose a large container, at least 50cm high and wide.
Select a sunny sheltered location.
Use top quality container planting mix, ideally one containing a wetting agent.
Water regularly to keep the potting mix moist at all times. During hot, dry weather, citrus in pots need a thorough soaking every 2 to 3 days.
Citrus need plenty of fertiliser. Feed with controlled release fertiliser in spring and autumn. Supplement with liquid plant food, once a week in spring and summer, fortnightly in autumn. Do not used concentreated powered fertilisers in pots as they may burn the roots, but the liquid manure from your worm farm is ideal.
Mulch with fine bark to retain moisture and protect surface roots.
Pruning is not generally necessary except for shaping or to remove dead or damaged wood. Remove shoots emerging below the graft union.
Trees can stay in the same pot for several seasons provided they are regularly fed.
Pest and disease control:
Spray with copper at petal fall and again two weeks later to control disease.
Spray with Spraying Oil during winter to kill insect eggs.
Watch for mealy bug and scale in summer - spray with Confidor at the first sign.
To control mites and aphids, mealy bug and scale insect during summer, mix Mavrik with Spraying oil at summer strength.
Watering the undersides of leaves helps deter mites.
Yellow leaves - Check drainage. Apply fertiliser.
Brown leaves - Make sure the tree is sheltered from cold wind.
Black mould on leaves - Sooty moulds are fungi, which feed on honeydew secreted by insect pests - aphids, scale, mealybugs and white flies. Spray to kill the insects and the mould will dry up and wash off in the rain.
Tree is shedding leaves - This may be caused by cold weather, wet feet or dryness.
Tree is shedding small fruit - Citrus trees often shed fruit in summer to compensate for size and health. Thin out heavy crops in early summer to help tree health.
Failure to set fruit - This may be due to: Dryness, lack of fertiliser or lack of bees (try hand pollinating).