Water and Fertilise
Avocado trees need plenty of water to thrive and keep their height down. It may be necessary to water them almost daily during dry periods and extra often when a tree is young. Established trees need to be watered deeply, infrequently and during dry periods, 3 times a week. To maintain soil moisture, a 2 to 3 inch layer of mulch should be placed around the tree, leaving a few inches around the trunk bare. Additionally, regular fertilisation of avocado trees is important. The tree should be fertilised using a balanced fertaliser in the early spring, and then once more every 8 weeks until late autumn.
Prune and Support
Pruning regularily is an important way to keep an avocado tree short. Pruning should be carried out during the off season, from late winter to early spring, when the tree is dormant. Pruning in this way will help to slow the tree’s growth and encourage fruit production. Using supports such as stakes and trellises can also be beneficial in keeping the tree short, as the supports will support the weight of the tree and help to hold it steady, even in windy conditions. The tree should be pruned to the desired height and then supported using the tie-down method.
Full Sunlight
Avocado trees should receive full sun exposure in order to keep them in a restricted format. Trees planted too deeply, shaded by tall buildings or other trees, or planted too close together can all lead to tall, ungainly trees. Places with especially warm climates can require partial shade; however, any area where humidity is high and the tree gets less than 6-8 hours of direct sunlight a day should generally be avoided.
Limit Suckering
Suckers are shoots that emerge from the soil near the base of the tree and can often be seen growing from the root system. Suckers will grow rapidly and rob the tree of resources, making it difficult to keep a tree short. In order to limit suckering, avoid overwatering the tree, and make sure there is good air circulation around the tree. Additionally, make sure the tree is planted in well drained soil, as poor drainage can lead to excessive suckering.
Manage Nuts
Nuts are the heavy fruit of avocado trees and can cause the branches to droop and the tree to lean if they are not managed properly. To keep the tree short, it is important to harvest the fruit as soon as it ripens and before it gets too heavy. Additionally, pruning back the branches that bear the heaviest fruit can help to take some of the weight off the branches.
Choose Varieties
When selecting an avocado tree, it is important to choose a variety that is known to stay short. Varieties such as ‘Littlecado’ and ‘Hass’ have been specifically bred to remain short, making them an ideal choice for keeping an avocado tree to a manageable size.
Maintain Ground Cover
Maintaining ground cover around the avocado tree is a great way to keep it short. The ground cover will act as a barrier and help limit the tree’s growth. This is especially important if there is a large amount of light coming in, as this can encourage vigorous growth. Additionally, ground cover can help to retain moisture and can even act as a natural weed killer.
