March Is a Good Time for Pruning, and More

by Henry Homeyer

CORNISH FLAT, N.H. – Traditionally farmers pruned their fruit trees and put wood ashes around their lilacs in March. And although this is a good time for both, you can do either earlier or later. I believe that because farmers couldn’t plant or work the soil in March, they did other tasks to fill up their days,  such as pruning.

If you plan on pruning now, please be aware of the danger of compacting the soil. Compacted soil has few air spaces and plants get their oxygen from their roots, not their leaves. Roots from trees can extend well beyond their dripline, and can be damaged by your footsteps if the soil is soggy.

If the soil is still thawing and is wet, it’s better to stay off it for now. If you have light, sandy soil that drains well, then you are fine. Clay soils are most at risk for compaction. Once you compact the soil, it is less able to drain away excess water, too. Just remember that the soil can freeze deeply, two feet or more, depending on snow cover, and a layer of frozen soil is like a layer of concrete. If you leave foot prints in the soil, don’t walk on it.

Don’t be afraid to prune, even if you have never done it before. Fruit trees grow vigorously when pruned, and even if you remove a branch and then wish you hadn’t, other branches will grow and fill in the space. You won’t kill your tree by pruning. But don’t remove too much: You can safely remove about 25 percent of your branches and leaves: your tree will still have plenty left to grow fruit and feed the roots.

Use a sharp pruning saw, not a rusty old saw you had when a Scout. You will rarely have to remove anything more than a two- or three-inch branch, so a folding ‘tri-cut” saw will be fine and can be purchased for around $25. Bow saws are not able to get in tight places, so are not recommended. A chain saw is rarely needed, and can easily remove too much wood too fast.

What should you remove? First, remove any dead branches. How do you know if the branch is dead, since there are no leaves? The bark will be flakey and a different color from healthy branches. For smaller branches, scrape the bark with your thumbnail. If it does not show green, it is dead. Broken branches should be removed, too.

Ideally, sunshine can reach every leaf of the tree. Leaves that are shaded by others do little to feed the tree. So if you have branches layered closely, one above the other, the lower branch is being shaded. Either remove it, or remove the one above it.

Often branches grow back towards the middle of the tree. These will create problems as they get larger, often rubbing existing branches and shading out others. So follow them back to their point of origin to remove them. Remove any branches that are rubbing or touching. Decide which is the better branch, and leave it.

Where should you make your cuts when removing a branch? Look carefully and you will see the “branch collar”. You will want to leave the collar as this is where the cut will heal. It is a swollen area where the branch and the trunk or a larger branch are joined. Often the collar has wrinkles in it. Cut just past the swollen, wrinkled area and remove the offending branch where it is circular in cross section.

Many fruit trees send up water sprouts: vigorous new shoots. In their first year they grow straight up and are the thickness of pencils. They should be removed every year. If you cut a bigger branch, you might get several water sprouts surrounding the cut that year, but remove them all next year. Water sprouts are a tree’s attempt to increase food production by making more leaves. Some trees do it vigorously each year, others respond to heavy pruning this spring by growing many this summer. Water sprouts rarely produce fruit — ever.

When I prune fruit trees, I pay attention to the fruit spurs that actually produce the fruit. When choosing which of two branches to remove, I leave the one that will be producing the most fruit. Fruit spurs are two- to five-inch branches that have buds on them. Fruit spurs produce both leaves and flowers, and need to be at least two years old on apples and pear trees to produce fruit, sometimes longer.

I often get complaints from readers about the fact that their young apple tree has not produced any fruit. Be patient, I say. Each variety of tree has its own schedule: dwarf or semi-dwarf trees produce fruit sooner than full sized trees. A newly-planted tree can take two to six years before the first fruits grow. I once had a plum tree that took 20 years to flower and produce fruit, and only did so when I threatened to cut it down if it didn’t produce fruit the next year!

Lastly, know that pruning your tree well will increase the size and improve the flavor of the fruit. It takes a lot of energy to produce fruit, so a tree that only grows 100 apples is better able to feed the fruit and grow the sugars that make it tasty than a tree that grows 1,000 apples. And really, how many apples can you eat?

As to that other March chore, improving the pH of the soil around your lilacs? Two dry quarts of wood ashes or garden lime will sweeten the soil if spread around your lilac. Lilacs do not flower as well in acidic soil, which is what most New Englanders have. It won’t affect this year’s blossoming, but should by next year.

So get outside on a sunny day and get to work. I always find something to do, and pruning is one of my favorite March activities.