Right now, as part of our autumn tree care program, we’ve started doing our fall soil amendment jobs for valuable, older specimen trees at a number of properties. We use techniques including removal of old mulch, removal of sod an competing ground cover, breaking up compacted soil and radial trenching with an air spade, and composting or renewing compost in the root zones to improve the soil health and vigor of these trees. Fall is really the best time of year for this work, because annual and perennial weeds are dying off and have less of a chance to populate open soil areas.
Mixing compost into soil will help improve soil structure, allowing inorganic particles (sand, silt, clay) to combine with organic content (compost). This allows the soil to develop a crumbly texture which means improved drainage while still holding moisture and nutrients for the roots to use. Composted soil is made up of many round, irregular aggregates, or groups of particles loosely bound together by secretions of worms, micro-arthropods and bacteria. This allows air to penetrate and holds moisture well but allows excess water to drain away. Tender young roots also have an easier time penetrating into the soil. Compost is especially needed in the organically starved sandy soils of Long Island. Water and nutrients pass through sandy soils quickly because there is nothing to retain them due to the coarse particles that make up the structure. In loose, sandy soil compost helps to bind these particles together and increase the soil’s ability to retain moisture and nutrients. Plant roots penetrate easily, finding moisture where there was none before.
It is vital to remove old mulch completely before composting. If the soil is compacted, an air spade can be used to form radial trenches from the trunk out to the drip line without harming the roots. This will allow the soil to lose compaction during the frost heave cycle. Compost will also help create air pockets in the soil through microbial action. Usually 2 inches of compost underneath a tree from right near the trunk out to the drip line is the recommended amount. We are careful not to pile compost against the base of the tree, because any organic material against the trunk can cause rot and disease or encourage insects. The root crown needs to breathe, which is why the worst thing you ca see is a mulch “volcano” against the trunk, usually put there by lawn guys or people who don’t understand trees.
Here are some photos showing radial trenching and composting that Fox Tree did to help strengthen and remove stress from an ailing beech tree in Bridgehampton.
Call Fox Tree today to have us look your trees over and recommend a fall tree care program, including a compost appliction to reduce tree stress in your valuable specimen trees