Water Your Evergreens

from the Morton Arboretum

The promotes attention and care to your landscaping all months of the year—not just when plants are in bloom. Do you have your lawn and garden ready for the first freeze?

Clean up
Discard of diseased leaves and fallen twigs or branches. Healthy refuse can be gathered and shredded with a lawn mower to serve as mulch for other landscape.

Protecting your supplies and your plants
Drain hoses. Stow hoses away for the season and make sure gardening chemicals are kept in a dry area over 40^degrees. Worried about grazing animals setting their sights your landscaping? Construct a "fence" out of chicken wire or hardware cloth to keep them away.

Look ahead
Start cultivating spring bulbs in containers to plant when the ground begins to thaw. You can plant bulbs in the ground before the first freeze.

Make sure you've watered evergreens and other landscaping before the ground freezes
As leaves dropped off trees this fall, something else dropped too: soil moisture. Amid the continuing dry spell, The Morton Arboretum urgently recommends that property owners water their evergreen trees and shrubs right now to maintain their health and vitality, and to guard against winter injury.

O'Hare International Airport received only 2.46 inches of rainfall since September 6, compared with the normal 6.59 inches, a deficit of 63 percent, according to National Weather Service (NWS) figures. The Arboretum, the NWS station for Lisle, IL received 2.95 inches of rain since September 6; a 57 percent deficit compared with the normal 6.8 inches.

"The soil is extremely dry," says Doris Taylor, who heads the Arboretum Plant Clinic, which provides free advice to the public on tree and shrub care.

Evergreen trees and shrubs "exhale" moisture 12 months a year. They require adequate water, even after other trees drop leaves, right until the ground freezes. A lack of proper moisture in the soil can leave plants without proper energy reserves for healthy growth next year. Also, as sun and winds dry out leaves (including evergreen needles) in winter, they are susceptible to winterburn, which shows up in the spring as brown and scorched leaves.

The Arboretum recommends property owners ensure that the top 12 inches of soil
around evergreens is kept moist until the ground freezes. To help determine a soil's
moisture level, a homeowner might find that a metal rod or stiff wire is the most
convenient tool. As the homeowner attempts to push the rod or wire into the ground, very dry soil will provide a great deal of resistance, and indicate the need for watering.

Certain types of evergreen plants are particularly drought-sensitive, including hemlocks, boxwoods, arborvitae, rhododendrons, hollies, and to a lesser extent: white pine.

Mulch is very helpful for conserving soil moisture. Organic mulch – such as long-lasting hardwood bark, composted hardwood chips and leaves – should be spread up to 4 inches thick around the tree. Keep the mulch from directly contacting the trunk. Avoid recycled plastic or rubber mulches – they do not provide nutrients and may create a barrier preventing oxygen and water from penetrating the soil.