Every once in a while, someone asks for a house call to diagnose their apple trees.

The most common complaints are that, while the trees are healthy and producing, the trees produce huge amounts of fruit every other year, and the fruit is small.

It is very disappointing when fall rolls around and your tree has no fruit.

If you understand how fruit development cycle, you can coax the tree to produce larger apples.

But, first the history of apples in North America

The domestic apple is not a native tree. It is the descendant of millions of Central Asian and European cross hybrids. Seeds collected from English cider works arrived on the New World shores along with the Pilgrims in 1620.

The Roxbury Russet is the first of the North American / European / Central Asian hybrids.

The original tree would be over 380 years old today, if still alive.

The tree is only available today because it was top grafted to wild crab apples and volunteers, which could be seen in the Angry Orchard orchards in Walden, N.Y. Today, the genetically identical, year old Roxbury Russet scions would be grafted onto rootstocks.

For those of you think, John Chapman, a.k.a. Johnny Appleseed, brought the apple to Ohio. No. It wasn’t. It was a guy named Rufus.

General Isreal Putnam, a Connecticut Revolutionary War hero and wolf killer, grew the Roxbury Russet in his Pomfret orchard. Isreal’s grandson, W. Rufus Putnam, settled the Territory West of the Ohio River in Marietta and established the territory’s first nursery, in 1796.

The Roxbury Russet then became know by two other names: the Marietta Russet and the Putnam Russet. By coincidence, I attended Marietta College and lived in Putnam Hall.

On growing large apples

It is an early spring. Penn State pomology reports suggest arrival is three weeks early.

The fact that my trees are already in the “silver tip” stage and will bloom before months end. The first to bloom will likely be the Summer Rambo, a 16th century French variety, which inspire the book First Blood by novelist David Morrell. Imagine David asking his wife, “Honey, what kind of apples are these?” The rest, as they say, is history.

Anyway, back to the bloom, when they do, the first bloom in the cluster is known as “the king.”

It is the largest blossom and will grow the largest fruit. It will be pollinated by native Blue Orchard Bees before the other blossoms have opened.

Then petals begin to fall, the pollinating cycle for apples will have been completed.

Pollination occurs when the pollen from the stamen of different apple tree makes its way to the stigma and the pistil to the ovule. The first petals to fall will be from unpollinated blossoms, the second from the partially fertilized, with the fully cross-pollinated being last.

The fertilized ovum begins the process of mitosis when cells divide, and divide again for a period of 20 days or so. This is when to induce the tree to produce larger fruit and to influence next year’s bloom and fruit set.

Only 3 to 5 percent of the blossoms need to be pollinated in order to have a fulsome harvest.

The king rules here. It is a keeper.

As uncomfortable as it sounds, remove all the other developing fruit except for the king, which is in the center of the developing fruit cluster.

By removing the other fruit, the trees then only need provide nutrients to one fruit instead of multiple developing fruits.

Each of those developing fruit has 5 to 10 seeds. Each seed contains the plant hormone gibberellin, which directs the tree to send it nutrients at the expense of next year’s developing buds.

Reducing that demand signal allows the tree to send nutrients to developing buds even as the tree is growing the current year’s crop.

Reducing the crop load is a lot of work, even if it is a small tree. Thinning a mature 20- to 30-foot tree is impossible. Think small.

Thin the developing apples within reach. Experiment. Thin one section and leave another alone, or use a broom to bat the blossoms out of a section and compare notes at the end of the season.

Commercial orchards thin blossoms chemically and by slapping rubber fingers through the branches to knock off blossoms.

With proper pruning, fertilizing and thinning you will grow bigger apples this year.

Peter Montgomery is the owner of Montgomery Gardens, Heirloom apples and Orchards at 45 Kent Road, Warren, where he manages a mixed fruit orchard, consults, designs and installs orchards throughout New England.