Dreaming of an Apple Orchard?

By Dr. Francis Gouin

A Bay Weekly reader bragged to me that he’d created an apple orchard by planting a single tree.

“So you purchased one of those trees with four to five varieties of apples,” I replied.

He was crestfallen at failing to fool me.

Before you buy such a magic tree, with multiple varieties of apples grafted onto a single stem, look closely at the pictures in the nursery catalog. Almost every catalog I examined showed a colored drawing, not a photograph. One catalog showed a photo, but the tree was young and appeared to be only seven or eight feet tall. The fruit was so evenly distributed that I strongly suspect the apples had been tied onto the branches.

Eating four or five varieties of apples from a single apple tree in the back yard is a great idea, but it is not sustainable. To produce apples, a tree’s flowers need bees to cross-pollinate with another apple variety. This is why orchardists plant several varieties of apples in close proximity.

In an orchard devoted to one variety of apple, they will plant a crab-apple tree for every 10 to 15 trees of the variety under cultivation.

One apple tree with four or five varieties grafted onto a single stem eliminates the cross-pollination problem. In theory, it sounds great. But within eight years, the number of varieties remaining on that single stem will be one or two at most.

Not all apple varieties have the same vigor, and the more vigorous will crowd out the weaker ones. This self-selection can be controlled by pruning the more vigorous growing variety severely every year. But you must be careful not to remove all of the fruiting stems. This can be very tedious, especially if you do not know what you are doing.

If the apple tree is not pruned properly, it can become lopsided and fall over, especially if the varieties are grafted on dwarf or semi-dwarf rootstock.

Also, as the weaker varieties are crowded out, chance cross-pollination by bees decreases — unless you have a crabapple nearby that flowers at the same time.

If your intent is to eventually harvest fresh apples, plant at least three different varieties. Remember that apple trees need to be pruned yearly for adequate light penetration for the fruit to properly color. If you intend to grow nice big apples, the fruit will need to be thinned by hand five to six inches apart.

Several diseases and insects attack apple trees. To fight them off, you’ll need to apply a dormant oil in late March, an organically accepted spray that suffocates over-wintering insects that hide in the bark and crevices or branches. You’ll spray again when the flower buds are just showing pink. To protect bees, never spray any tree or shrub when in flower. It’s a Maryland law.

Sprays are again applied during the summer months to control apple scab on the foliage, railroad worms and apple maggots. Some varieties are much more susceptible to apple scab than others. Read the descriptions and select varieties as pest-free as possible.

After all this, you may decide, as I have, that it is cheaper and less time-consuming to purchase apples at your local farmers market.