A well-grown fruiting avocado or alligator pear (Persea americana) is a wonderful sight. The trees are prolific croppers, and once established can provide up to 50kg of fruit a year. Despite being grown in the warmth of Mexico and Central America for some 10,000 years, there are now cultivars that will tolerate nights as cool as 3.5ºC. So if you can grow a good lemon tree, you can certainly grow an avocado.
Avocados thrive on rich, well-composted soil. Their shallow roots need moisture, but can be prone to fungal rootrot in saturated soils. Plant in a deep, well-drained soil with added compost.
If you’ve inherited a healthy-looking yet barren tree, chances are it was grown from seed. Seed-grown trees can take up to seven years to crop and may produce little fruit. For crops in three to five years, buy a named, grafted cultivar from a nursery, and check if you need two trees to ensure good pollination.
How to plant
Choose a spot with full sun all year round and shelter from strong wind. Allow room for the tree to spread. Plant during warm months. First loosen the soil, then work in plenty of organic matter to about 60cm deep. Try a mix of mushroom compost and cow manure. Then dig a planting hole as deep as the roots are and about twice as wide. Plant, water and mulch.
Caring for avocados
Regular watering is essential. Feed plants four times between spring and autumn with an organic fertiliser, and again once they begin to crop. Boost your tree each spring by applying a trace element fertiliser. In inland areas, which often have boron-deficient soils, add a mix of 1 teaspoonful of borax powder to 4.5L water. Apply every three years.
Expert growing tips
- Choose a variety to suit your climate.
- Thin-skinned cultivars, such as Bacon, may be prone to fruit fly attack. You can use baits to check for their presence.
- When new spring leaves start opening, apply potash to prevent anthracnose, a fungal disease that can spoil productivity.
- Avocados hate salty or grey water, so always water with rain or tap water.
- Never hoe or dig around the bases of trees. This damages the feeding roots.
- Trees can be briefly deciduous in winter; don’t worry, foliage is quickly renewed.
- Little pruning is needed. Remove weak, dead or crossing branches as they occur.
- To shape young trees, pinch out shoot tips. Prune adult trees after harvesting.
Fruit can be picked once it has finished swelling. This is trial and error, but picking too early can make the fruit shrivel. Cut off each avocado so it retains a piece of stalk – this helps to complete ripening. Take indoors and handle with care as the skins are delicate and the fruit bruises easily. They are ready to eat if slightly soft when pressed.
Did you know?
Fully formed avocados ripen much faster off the tree, which may take around 10 days. Keep indoors, but don’t place fully ripened fruit in the fridge, as temperatures below 10°C can spoil them.