June 2012

Some old landcape practices die hard

Building mulch like a volcano around a tree keeps the bark moist, inviting insects, disease and rot. © Jo Ellen Meyers Sharp

Here are a few old gardening practices that seem to linger:

  • When planting a tree or shrub, what comes out of the hole should go back into the hole. Do not amend the soil with peat moss, compost and worse, granular fertilizer.

Amending the soil discourages roots from reaching out beyond the peat or compost to find nutrients.

The worst thing you can do is mix granular synthetic fertilizer in the planting hole. The fertilizer can burn the roots of the plant and kill it.

Perennials and annuals benefit from a well-prepared planting bed. If that is not possible, throw a trowelful of compost in the planting hole or mix it with the soil and plant.

If you must fertilize new plantings with a granular product, sprinkle it on the soil surface after planting and water it in. Organic fertilizers usually do not burn plants. Always read and follow the label directions of the product you use.

  • Mulching newly planted trees, shrubs and other plants helps the soil retain moisture, moderates temperatures and reduces weeds. Mulch can cause rot or rob nutrients, such as nitrogen, when touching plants.

With mulch, more is not better. The practice of building mulch like a volcano around trees is damaging and wasteful. Mulch piled around trees keeps the bark moist, an invitation for insects and disease.

Three to four inches of mulch around trees and shrubs (two inches around perennials and annuals) is all that’s needed. Too much mulch around trees also encourages surface roots rather than deep ones. Too much mulch also can suffocate roots.

  • Do not top trees.

The message has been out there for 30 years, yet there are people who continue to provide that “service” and property owners who allow it. Don’t do it. It is a death sentence for your trees.