Water is the most essential resource for a tree’s survival and growth. An increasing number of farmers in Uganda are beginning to appreciate the need to water trees during drought, especially fruit trees like avocado, mangoes and oranges.
However, many farmers of do not realise is that a tree can also be harmed with too much water. The symptoms for water-starved trees can be the same as symptoms caused by water-logged tree roots.
Symptoms for both under-watering and over-watering are wilted and scorched leaves. Both conditions can prevent roots from transporting water to the top of the tree.
In addition, too much water can shut down oxygen to the roots. Some tree species can handle “wet feet” but many trees cannot.
How to water
Supplemental watering during drought conditions can prevent trees from dying, stop pests and non-recoverable roots and canopy damage.
Young trees are prone to drought. They need regular watering during the dry season. Depending on the soil texture, presence of other plants competing for the same water, daily temperatures, and rainfall amounts, 1-3 inches of water per week should keep a tree healthy.
Trees should be watered once or twice a week in the growing season if there has been no significant rainfall. If the leaves are wilting and you have regular watering, you need to check if there is too much water for the tree.
The best way to check for wet soil is to dig about 6-8 inches and fill the soil. The soil should be slightly moist but not soaking wet. You should be able to press most non-sandy soils into a ball and it stays together. If the ball of soil falls apart, then the soil may not have sufficient moisture. If the ball of soil crumbles when rubbed, it is an indication of too much water, so watering should be stopped.
Sand and clay soils are not a good tree growing medium in the landscape although many species have adapted to these soils.