River Birch tree bed

Everything changes. Our whole life is changing, but there are smaller changes in the world, like changes  in cultivation rules, come to all gardeners with some regularity.

We have been planting trees and shrubs in Greenfield and have followed new rules, and rubbed up against others unhappily.

One old practice, if not a rule, about planting trees was that you could leave on the wire cage if it came with one, and that you could leave the ball and burlap if it came to the garden that way. I don’t really understand the rationale about leaving those constraints, but I do know of a case where a person had a landscaper plant several trees and they were all dead or dying the by the following year. A different landscaper was brought in to investigate and discovered strangled roots caused by the intact wire cage. This did not seem like a surprising outcome to me.

Even planting a tree with burlap holding soil and the roots together needs to be undone. The burlap can be cut away, and beyond that, the roots should be disturbed. The situation is similar for container grown trees. I bought two container grown trees, and when I finally got them out of the container it was clear that there was very little planting medium left and that substantial roots and just grown round and round inside the container.

We dug planting holes that were at least twice as wide as the container, but not much deeper. The soil in our new garden is heavy clay and I simply could not bring myself to use this soil without adding compost. The newest thinking about planting trees and large shrubs is that if you add fertilizer or large amounts of compost the roots will be happy growing in the planting hole until they need to grow into the surrounding soil, which they do not find enticing. Also, large amounts of compost will rot over time and the tree will sink slightly.

So I confess, I did add some compost, and a measure of loam to the removed soil. I also loosened soil within the planting hole. Before planting I cut and untangled the roots as best I could and gave the root-bound mass a vigorous watering with the hose that also helped loosen the roots. The disturbed roots will then start growing new roots. I made sure not to plant the tree too deeply. The planting hole more resembled a bowl than a pit.

The new thinking about what to do after the tree is planted and watered properly is to spread a layer of compost and mulch around the newly planted tree. It has been pointed out that this is the way Mother Nature enriches the soil, from the top down. Because my design plan is to have wide tree and shrub beds separated by curving paths I have been using the lasagna method with compost, cardboard and mulch over the whole area of the bed.

In this case I have not completely followed the rules and we’ll have to see how things come along. So far so good, but that is not proof. Indeed it will not even be proof that breaking the rules is proof that the rule is not correct. I always say there are many mysteries in the garden, and other people say you can not always claim that result B was caused by action A. Sometimes it is hard to pin down a cause.

The final part of planting a tree is staking it. Or not. I certainly remember the careful directions for staking a tree carefully. I think I may even have staked a tree or two, with firm wire and old hose length and stout stakes, but usually I was too busy or too lazy and most of our trees did fine without a stake. Now the official word is out. Staking not needed. A tree swaying in the breeze is getting just the exercise it needs to grow strong.

Recently my husband and I have been having what we like to call discussions about the benefits of mulching with arborist wood chips. Last year I got a couple of big free loads of chips from the arborists clearing along the side of the road. My husband retains the view that wood chips will tie up the nitrogen in the soil and make it acidic.

I counter by quoting Dr. Linda Chalker-Scott Associate Professor at WashingtonStateUniversity, author of The Informed Gardener and other books, and a participant in The Garden Professors ™ blog. According to research arborist wood chips were one of the best mulch performers in a group of 15 in terms of moisture retention, temperature moderation, weed control and sustainability.

One of the reasons for their benefits is that arborist wood chips are made up of bark, wood and leaves. The physical diversity of these materials reduce compaction that will occur with sawdust or bark mulches. Different elements in wood chips mulch break down at different rates and so create a diverse environment that encourages diverse biological and bacterial life in  the soil.

Often wood chips can be acquired at no charge. Using local wood chips will keep them out of landfills, and this is another environmental benefit.

I am using some bark mulch in my new Greenfield garden beds, but I am bringing down as much of my Heath wood chip pile as I can. I am working on improving my soil structure and adding some enrichment. Mulch applied before weeds arrive will keep the weed count down – just exactly what I am trying  to do now.

Science is always refining its knowledge. Advice is always changing, and while it can be hard to give up old habits and methods, I try to keep up with new research and new ideas about the best ways to garden.

Between the Rows   August 15, 2015