Citrus trees are beautiful and awesome fruit bearers.
Citrus are shallow rooted trees that must have good drainage and plenty of sunlight. Citrus will grow in most soils except poorly drained wet soil. When young lemon trees are carrying lots of fruit or lots of flowers and buds make sure you prune and pick most of them off the tree otherwise they will retard the growth and cause yellowing and shedding.
All lemon and citrus trees can be grown in tubs. The tubs size being bigger is much much better the citrus being given lots of water really along with really good potting soil and regular feeding and pruning will be an amazing plant.
Pests and Disease
Scale – in summer time scale is common on citrus. Ants can often be crawling up the trunk to get the sugars produced by the scale which are oval shaped bumps adhering to the stem and leaves (brown or white). Pest oil or eco oil sprayed over the whole tree is safe and effective. Don’t spray if over 25°C.
Citrus Gail Wasp – A gail wasp infection will be swellings of the branches and distorted fruit. Gail wasp traps can be hung in the infected tree from August on but will work better if the worst of the infected wood has been removed first. Cut this away and galls need to be removed by the end of August too.
Citrus Leaf Miner – the leaf miner starts in the warmer months and mainly attacks the new growth of trees. Citrus leaf miner is identified by squiggles in the leaves as well as the leaves are distorted. You can control these with regular applications of pest oil.
There are many cause for citrus trees to look sick or yellow. Here are a few to keep an eye out for:
- Collar rot can cause extensive leaf drop. This is more common in older trees. Check the lower trunk for rotting bark.
- Too many buds and fruit in younger trees can lead to yellowing and leaf drop. Keep a young tree well pruned by removal of buds, fruit and feed moderately in spring time.
- A lack of food and or water in late spring and summer time may lead your citrus tree to looking a bit sick. Feed with citrus or complete fertilizer (not in pots), for the ones in tubs use a slow release like osmocote. Water frequently in summer time as citrus are surface rooting.
- Lastly porrly drained soil can cause yellowing or leaf drop, make sure your citrus is not sitting in water and is being well drained.
Pruning your Citrus
Prune your citrus hard (right back) if the plant looks dried out is shedding it leaves or yellowing. Spring and summer time are the best times for pruning. Some fruit and flower might have to be sacrificed but it will be worth it to keep your plant healthy, thick and bushy. Citrus are sturdy plants and can be leafless but will still recover if nurtured back to health by pruning, feeding and watering unless you have poor drainage or collar rot.
Common Citrus Plants
Navel Orange – thick skinned, seedless. Bears in winter and early spring. A warm sheltered position to grow in.
Mandarin – Fruit should not be left to ripen on tree
Grapefruit – Needs a warm shelter to grow
Lisbon Lemon – Thick skinned long bearing fruit. Thorny medium height and strong flavor