Low precipitation and midsummer drought conditions can adversely affects trees and shrubs and overall plant health. Both the mortality of newly planted trees and shrubs and the growth and aesthetic appeal of established landscape plants can be compromised. Signs of stress from poor water conditions include wilted leaves, marginal scorch, or leaves dropping prematurely.

When drought strikes, many trees like pine and sugar maple, are less capable than usual of dealing with plant stress because their root systems are damaged. This can make them more susceptible to insects and diseases that normally pose little threat to tree health.

It’s important to maintain soil moisture in the optimal range in order to protect and preserve plant health.  There are a number of steps you can take to counteract the effects of dry weather and protect your plants from drought conditions.

Start early by installing some form of drip irrigation before possible restrictions on water use comes into play. Sprinkler irrigation wastes water and may lead to foliar diseases. A drip irrigation system uses much less water and delivers it more effectively to the root zones of trees and shrubs. Drip irrigation is an effective way to replenish the moisture in the soil without leaving the root ball saturated for an extended period.

Another more environmentally friendly technique is to divert water from downspouts or use rain barrels to capture rain water. This stored and diverted water can be used to irrigate trees and shrubs rather than letting it run into storm sewers.

Irrigating Newly Planted Trees
Newly planted trees may require more regular watering than established trees and shrubs. Drip irrigation works great for new plants, but how often and how much should you water? Here’s a quick reference guide. A 24-inch root ball requires 2 or 3 gallons every four or five days. If you don’t have a drip irrigation system, another solution would be to poke a few nail holes in the sides of a 5-gallon bucket near the bottom, put the bucket next to the trunk and fill it with water every few days.

Irrigating large trees
Typically, the larger a tree, the more drought-tolerant it is. This is because a well-established tree has a massive root system, can tap into subsoil moisture. In drought conditions however, when subsoil moisture has been depleted, trees lose this advantage and must compete with other plants for available moisture. While it is normally not necessary to irrigate established trees, it may be advisable to do so during extreme dry spells.

First, it must be understood that it will take a tremendous volume of water to replenish the soil moisture throughout the entire root zone of a large tree. Fortunately though, wetting even a small portion of a tree’s root zone will greatly reduce drought stress.

Using a soaker hose of some type is the best way to irrigate large trees. A 50-foot length of hose running it for about one hour will wet a band about 2 feet wide with about 200 gallons of water. This is the equivalent of about 6-inches of rain. Repeat this procedure three or four times in various locations during drought conditions to help trees maintain proper moisture.

Mulching Helps Retain Tree Moisture
Applying a layer of mulch 2-4 inches deep around trees and shrubs can also help conserve soil moisture. Care should be taken to not allow mulch to be piled near or touching the base of trees or shrubs. Keep mulch several inches from stems or trunks. Mulching will reduce the need for watering. Depending on your location, organic mulch such as finely chopped leaves or pine bark maybe available. Organic mulches also help to slow evaporation by keeping the soil cool. Adding composted manure and other organic matter also increases the water holding capacity of the soil, which is particularly critical for sandy soils.

Fertilizing During Dry Spells
You should also be cautious using fertilizers during long dry spells or prolonged droughts. Its okay to fertilize during short dry spells if you know you’ll be watering on a regular basis throughout the entire season. Over fertilizing in dry periods can end up killing or damaging plants and having an adverse affect on tree health.

The certified arborists at Tree Tech recommend applications of liquid bio-stimulants which are not like a traditional fertilizer.  This product, while delivering moisture to the root zone, improves the quality of the soil making it more hospitable for the uptake of water and nutrients.  Similar to what is found on a forest floor; these organic, bio-stimulants help create an environment that plants are meant to thrive in.

For a free evaluation of your landscape plants or for more information on preserving tree and shrub health, call the certified arborists at Tree Tech. We’ve been serving Massachusetts and Rhode Island with the highest quality tree care service since 1986. Visit us at www.treetechinc.net for more information or call 888-873-3832.