In the home landscape and commercial landscape this sustainable nutrition is missing. During building and development the soil structure is destroyed resulting in poor fertility. Then lawns are planted and autumn leaves are removed. Newly planted and pre-existing trees struggle to find adequate nutrition in the soil.

It was once thought that synthetic chemicals alone could supply the missing elements. Scientists now realize the folly of this assumption. The typically excessive nitrogen, for example, in average fertilizer causes rapid but weak growth. The nitrogen pulls energy away from the natural defenses creating thin cell walls more open to insect and disease attack!

The latest research shows the closer we can duplicate the fertility of the natural forest floor the more we can provide the balanced nutrition needed not just for new growth, but strong defenses.

A little known fact is that tree roots grow in the winter. This is especially true when they are insulated by a mulch layer or snow cover. This slow winter growth makes fall an excellent time to fertilize, ideally with an organic fertilizer that will break down slowly providing nutrition throughout the winter and into spring.

The extreme drought in the summer/fall of 2000 plus the many insects and diseases that sapped the energy of our trees make me say please start or continue a tree fertility program.

Addendum to last article about pruning: Winter is the best time to prune trees. See the last article for all the real reasons trees might need pruning. Don't forget a trained professional can determine live limbs from dead limbs even more easily in the dormant season than when a full canopy of leaves blocks the view of the tree's limb structure.

Rob Frothingham
Certified Arborist, Landscape Architect