Water trees deeply and slowly

August 08, 2010|By CELESTE MAIORANA / Special to The Herald-Mail
  • Sandy Scott, Washington County Forest Conservancy District Board member, and her husband, Jon, are seen slow watering the American chestnut grove planted by the Forestry Board in April 2010 on Boonsboro park land. The Scotts are still setting up the containers in this one. They have a gasoline-powered sump pump to move water from the stream up the hill to the trees.
Photo by Celeste Maiorana,

When a tree is planted from seed, the root sprouts and reaches down into the ground before the leaves emerge. In this way, the root is ready to anchor and support the leaves with water and nutrients when the seed is depleted.

But even in nature, some years are hard on seedlings, and prolonged dry periods can result in many of the seedlings dying back to their roots. Even then the seedlings may not have died. If they had favorable conditions in their initial growth, the roots might have the ability to sprout new tops, and try again. The roots of forest understory deciduous trees can be several years older than their tops.

Most trees that we plant are dug and re-planted as balled or bare-root trees, or after spending some time in containers being carefully nurtured. The balled and bare-root trees have lost the balance between their roots and leaves, and all newly planted trees will take some time for the roots to establish their connection to their surroundings.


Because a lot of root growth occurs when the leaves are dormant, late fall and very early spring are the best times to plant trees to ensure survival. Well-planted trees might get by on rainfall alone. But even if the trees we plant could limp through their summer without our help, they will grow faster and look much better if they are watered regularly when the rains fail to come.

The faster a tree grows, the more carbon dioxide it extracts from the air and the more oxygen it puts into it. Thus a vibrant, rapidly growing tree is a real asset to the planet as well as a pleasurable sight to the gardener.

Water this year's trees as you would your tomato plants. If you haven't received an inch of rain within one week, give them a drink.

The amount you give depends on the size of the tree. You want to mimic an inch of rain falling slowly onto the surface of the root area so that it all sinks in. A year-old seedling might need only a gallon or less of water while a larger tree might need five or more. It is better to water deeply and less often than to water shallowly and frequently. This encourages deep-root development, making the plants less susceptible to dry surface conditions.

If you don't have time to pour water slowly onto the ground, soaker hoses, buckets with drain holes in the bottom, and water gaiters can help. It is also good to keep grass and weeds away from your trees and mulch them lightly to conserve moisture.

The trees that have been planted in the last couple of seasons should not be forgotten either. They will benefit from a deep watering if there is a prolonged dry spell.

Once the ground becomes deeply dry in summer, rain will not penetrate very far below the surface until there is a period of steady rain for multiple days. The scattered thunderstorms that blow through cool and refresh the trees but do not deliver water to their roots.

While older and larger trees need a greater volume of water, they have a better storage capacity and need to be watered less often. Street trees are particularly vulnerable to hot dry periods because the area available for rain to penetrate is relatively small.

When the summer days turn hot and dry, watering your trees is a great relief.

Celeste Maiorana is a member of the Washington County Forest Conservancy District Board, which promotes forest conservation in Washington County. For more information, go to .

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