How Far Apart Should You Plant Fruit Trees?

Q. I know that the fruit trees at the orchard are spaced closer together than "recommended" spacing.  With the way that they are pruned, it works out really well.  I was wondering if you remember how far apart they are spaced, and how distant the rows are from one another.

UNCE Orchard square spacing of ten feet between trees
and between rows. The trees are about 15 years old and
wood mulch is covering the soil. Trees are watered using
a bubbler and basin that floods an area about six feet
in diameter under the tree. Thre orchard aisles remain dry.

A. The density of trees at The Orchard might be considered "moderately dense". The trees at the Orchard are spaced at ten foot (3.3m) intervals in the rows and ten feet between the rows. If I were to do it again, I would use the ten foot spacing between trees but ten feet between rows is a bit tight if you want to get anything wider than a human torso down the row. Spacings closer than ten feet apart in the rows will probably result in hedgerows where you cannot easily walk around an entire tree in the row.

I would space the rows 12 - 14  feet (4.0 - 4.6m) apart for more convenience.  You can actually space them closer than 10 ft apart in the row but at about an 8 foot spacing you would probably no longer be able to walk around each tree individually and the row would be maintained more like a hedge-row. They are pruned to a height of about six and one half feet tall as well for ease in harvesting, thinning, spraying, etc.

One part of the orchard is on "square" spacing and another is "triangular" spacing. Square spacing is where the trees are directly opposite each other in the rows and between rows. In triangular spacing every other row is offset half the planting distance. This actually gives you a little bit more spacing between trees in adjacent rows; about 13 ft (4.3m) instead of 10 ft. Triangular spacing also reduces shading from adjacent rows if you plant East and West rather than the traditional North and South row orientation in moderately high density orchards.

All of these trees are standard sized fruit trees on "normal" rootstocks, not dwarfing rootstocks with one exception: apples. Apples are on M111 semi dwarfing rootstocks which keep the trees normally at about 80% of their full size. The rest of the "dwarfing" to keep them bearing at this spacing is done through aggressive pruning.

Let me explain further. These trees are pruned aggressively in the winter months (dormant pruning) and also summer pruning which is actually done in mid Spring, around April. Summer pruning is the removal of very aggressive (stems that shoot straight up, called watersprouts) new growth. This can be done by pulling this type of growth out of their place of orgin. At this time of year, they will pop out by pulling very easily.

The older growth is not pruned at this time. That is normally done only in dormancy unless I see something that was missed. Then I might prune it out but that rarely happens.