Mulching serves multitude of purposes

By Bev Johnson | The Daily Journal

Published Friday, March 7, 2008

Bunkey is having his usual hissy fit. This time about wood mulch. His friend George keeps harping on why mulching trees is so important, and his wife Petunia keeps hitting the newly planted trees when she mows the grass. The idea of mulch is to protect the trees from Petunia and the lawn mower, and help keep the soil moist and cool under them. Bunkey's problem is what kind of mulch he should use.

Wood based mulches are derived from two main sources; materials harvested specifically for lumber production and materials harvested from land clearing or storm damage. Lumber mills debark trees in the process of squaring off the tree. The bark and excess slabs are shredded to produce mulch.

This is usually a mix of local hardwoods. This shredded bark mulch has the shortest life span, about 1 to 2 years and is the least expensive. Since it rots quite quickly, it is ideal for a spot that needs humus.

Adding nitrogen to the bark will hasten this process.

Pine bark mulch is more interesting as the pieces have a layered look. This also lasts longer, two to three years.

The more exotic mulches; shredded cypress or cedar bark will last up to 4 years, hold its color longer but costs more as it needs to be shipped here. It also smells nice, for awhile, anyway.

So what about all those colored wood mulches? They are often made of shredded slab wood that can be died. Bark can't.

They have a two- to three-year life span but can add a lot to a landscape as they can compliment your house or make a dead area pop out with a contrasting color. A light colored mulch around a tree in a deeply shaded area will make the spot look lighter.

If you are mulching to prevent erosion, don't use wood chips as they will float away with the rain. Instead use the fibrous bark. It has a tendency to stick together and stay in place.

Check to see if one of the electric companies is having trees trimmed in your area. The tree trimmers will happily dump a pile of trimmings on your lot. In the summer, this will include leaves.

Leafy mulch will rot quite quickly as it is almost a premade compost pile. Let this sit for a year to work and cool off. It will heat. Just the opposite of what you want a mulch to do. Stick with leaves or grass for your flowers. Wood takes up too much of the nitrogen in the soil as it rots.

You will need to add nitrogen to any mulched area to replace what the mulch uses.

Be positive. Mulching season is coming — eventually.