Water to Keep the Soil Moist
Before planting a fruit tree, Tom Spellman suggests soaking its root ball in water, fully saturating it. After planting, use a hose to soak the roots, collapsing any air pockets. It can take up to six watering sessions, spread throughout the first day of planting, to thoroughly drench the soil around the root ball.
After this initial watering, check the soil’s moisture level with a moisture meter (about $10 at garden centers) to determine how much and how often to irrigate, which changes depending on the season. Using the moisture meter, probe the soil at the drip line (underneath the tree’s outermost branches) in a few spots. Spellman likes to check the soil 18 and 36 inches away from the trunk at different depths after clearing away any mulch. At sunrise, water the tree from the drip line out, and about 1 or 2 feet away from the plant, until the meter reads moist. Plan on taking readings at least once a week during the growing season. Basing the watering schedule on visual cues alone is difficult. “The signs that a tree is over-watered look very similar to ones that it needs water,” Spellman says. “In both cases, the foliage droops and drops because the roots aren’t taking up moisture.”
Mulch for Beneficial Bacteria
A layer of mulch around the base of the tree does more than moderate soil temperatures and moisture while blocking weeds. The right kind of mulch can boost the biodiversity in the soil, which promotes root growth. Spellman says a 4- to 6-inch-thick layer of mulch is ideal, consisting of as many different types of organic material as possible. His rule of thumb is no one material—compost, wood chips, grass clippings, shredded leaves, pine needles, or wood nuggets—should be more than 10 to 20 percent of the final volume of mulch. Use an online calculator to determine how much volume you need, then mix together bags of varied materials, keeping the best-looking mulch, such as wood chips, to spread as the top layer. Keep the mulch about 6 to 8 inches away from the bark to prevent rot.
Switch Up Your Fertilizer
Spellman uses specific fertilizer formulations based on what he wants from the tree. For the first two or three years after planting, he focuses on growing the tree to a mature height, not producing fruit. For that, he uses a fertilizer consisting of a nitrogen (N) level that is two or three times higher than the phosphorus (P) and potassium (K), like a 16-4-8 blend focusing on vigorous green growth. Feed the tree according to the directions on the bag until the tree reaches a manageable height, around 7½- to 8-feet tall. Pruned to stay at that height, a peach tree, for example, produces about 50 pounds of fruit over two weeks, not the 350 pounds a 20-foot-tall version yields in a commercial orchard.
Once the tree reaches a size that’s easy to maintain, switch to a fertilizer that supports developing roots, flowers, and fruit. Spread a blend that has a nitrogen level that is two or three times lower than the phosphorus and potassium, like a 3-12-12, so you don’t spend time pruning unwanted growth. Feed in early spring and midsummer.
Note: Growing a fruit tree is a long-term project and not one you can necessarily speed up by spending more money on more mature stock. A 7-year-old tree might provide a few more pieces of fruit faster than a 2-year-old one, but what really makes a difference is the time that the plant has spent establishing itself in your yard. Normally, it takes about three years for a tree to acclimate to your conditions before it approaches peak fruit production.
Prune for Shape
Spellman does most of his pruning during two sessions. He controls the overall size of the tree in the summer, between May and August, by cutting off any branches that extend beyond the established habit. This is also a good time to spray the tree with a garden hose fitted with a high-pressure sprayer; the blast of water is enough to clear dust, cobwebs, aphids, and scale from the tree, but not so strong it will damage foliage. Later, in winter or early spring, more detailed pruning takes care of potential problems like crossed branches, poor air circulation, dead or diseased limbs. Pruning back old wood also rejuvenates the tree.
Note: It’s important to properly identify a disease or infestation before spraying anything on a tree. If you don’t know exactly what the disease or insect is, put a damaged leaf or branch in a zip-top bag and take it to a nursery that specializes in fruit trees for a recommended treatment. You can avoid a lot of problems by keeping your fruit tree clean.