Conserve Moisture- Mulch!
Put mulch around all trees twice a year to maintain a layer between 2 and 3 inches deep.  Mulching keeps weeds and grass away from trees so they won’t use the water before it gets to the tree roots.  Mulch around your trees also conserves moisture in the soil, adds nutrients and organic matter, and keeps it cooler. Check out our Mulch Meters for additional tips on mulch.

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Fertilize Properly
Please do NOT fertilize newly planted trees. In later years, fertilizing might be beneficial (see 'Deep Root Fertilization' below). You can get help to determine appropriate methods and rates of application by contacting the University of Maryland Home and Garden Information Center at 1.800.342.2507, or www.hgic.umd.edu.

Deep Root Fertilization
You may not hear them complaining, but your trees are hungry.  Trees growing in our yards and cities rarely receive the same nutrients they would if they were growing in a forest.  In order to increase your trees’ vigor, deep-root fertilization can add those nutrients back into the soil.  Well-nourished trees are stronger and less susceptible to disease, insects, drought, and other stresses.

Deep-root fertilization effectively provides nutrients to trees because it is directed to a tree’s feeder roots.  Getting fertilizer below the grass to the roots of trees is important and not overly complex.  Many licensed tree care companies offer this service, but it can also be done on your own with the proper supplies including an auger or fertilizer probe, hose, and a measuring tape.

“How to” Deep Root Fertilize:

- Always follow the directions on the label of the fertilizer.
- Test your soil before fertilizing to determine what is lacking.  Click here to learn about collecting and mailing your soil sample.
- Never fertilize a newly planted tree. After two growing seasons, test your soil to see if fertilization is needed.
- Time it right: Fertilize in October or November to encourage root development and/or in March or April, just after the soil has thawed to encourage tip and leaf growth.
- Choose a fertilizer for trees; it’s not the same as fertilizer for grass.  Look for “Tree” or “Evergreen” (if you have pines, spruces or other trees with needles) and water insoluble nitrogen (WIN) on the label. Good fertilizers can be found at home & garden or hardware stores and cost about $1-3 per pound.
- Use a slow-release fertilizer to protect the quality of water in our watersheds.
- Choose your method of application:

- Fertilizer stakes are pushed into the ground below the grass, 
- Granular fertilizer is placed into in holes you drill in the soil (about 10 inches deep), or 
- Liquid fertilizer is injected 8-10 inches below the surface into the soil with a probe