Established Trees

If you've made a good choice, care of your mature tree should not be very difficult. Some attention to basic details will help you have a tree that adds beauty and benefit to your landscape.

Watering. As with the young tree, an established tree needs moisture to thrive. If you have chosen one that does well in the Stillwater area, you should have few difficulties. However, even a drought tolerant specimen may need some assistance. A regular watering schedule in very dry weather is a good idea. Deep, thorough watering done occasionally is much better than shallow watering done every couple of days. The clay soils common to Stillwater need less frequentwater applications than well-drained sandy soils. But clay absorbs water more slowly than sand, so clay soil needs more water at a given time to penetrate to any given depth. Put a hose at the base of the tree and allow a trickle of water to flow for at least 45 minutes.

Mulching. You've probably already mulched your tree when young. But just because it is now established is no reason to give up on a habit that does so much good. Mulch still should be laid in to a depth of 4-5 inches in a ringapproximately 3 feet around the tree. Mulch serves many purposes: It retains moisture - evaporation is greatly slowed by mulch around the tree It insulates soil - the temperature of the soil is much more constant under a layer of mulch. Soil at an even temperature is much more hospitable to earthworms and natural bacteria. These keep the soil healthy and better able to support the nutrients for your tree. It keeps out weeds-while mulch won't totally remove the weeding chore from your life, it will retard weed's growth It reduces lawnmower and weedeater damage - the mulch forms a kind of "safety zone" around the tree where mowing and weedeating are rarely needed It prevents soil compaction - even a lot of walking can compact the soil near the tree. Compacted soil reduces the amount of water and oxygen that can get to the roots.

Be sure not to pile the mulch heavily up against the tree trunk - you could be building a home for insects or building up moisture and causing rot.

Winter Care. Water trees well in advance of any hard freeze. Plants that enter winter in dry soil have no moisture reserve in the root zone to counteract drying winter winds. The result can be dehydrated, dead plants. You can also water in the winter when temperatures are above the mid 30s.

Fertilizing. An annual output of strong new growth with good color tells you that the plant is doing well without your assistance. If the tree has smaller or paler leaves than normal, if new growth is slight or weak, or if the tree seems have a lot ofdeadwood, you may need to add fertilizer. Use broadcast lawn fertilizer overtherootzone,atthesametimeyoufertilizethelawn. Don't fertilize a perfectly healthy tree "just to be safe"; unnecessary fertilizer can promote young, vulnerable growth attractive to pests or can burn delicate roots.

Protecting the root system. Eighty-five percent of a tree's roots can be in the top 24 inches of soil and can extend out as far as the tree is tall in really good soil. In poorer quality soil, roots usually extend to the dripline (outer reach of the branches).It is extremely important to protect these roots because they provide oxygen and water that a tree needs to survive and grow.

Construction equipment, vehicle traffic, lawn maintenance and foot traffic can all compact the soil. Compacted soil reduces the amount of water and oxygen that can get to the roots, and severe compaction can literally suffocate a tree to death.

To prevent compaction, landscape in a fashion that discourages heavy traffic directly over the root system. Use mulch under established trees. People are less likely to walk on the groundcover. Ifyou must have a walkway under an established tree, use mulch or gravel under a tree rather than continuous cement walks that can smother the roots.

If there is construction in the area, put up barricades around the area covered by the crown of the tree to prevent compaction by heavy equipment. Any new construction around an established tree can cause damage - and that injury can accumulate over time. If the contractors are trenching for utility lines or pipes, have them avoid the tree area.