Fruit Tree Site Selection (cont)
By: National Gardening Association Editors
Conditions Fruit Trees Like
Your Extension Service agent can provide useful soil survey information. Fruit trees need well-drained soil. Avoid low areas where water puddles during rains. If you don't have any well-drained sites, you can install drainage tiles or build raised mounds or beds (6 to 8 inches high and as wide as the mature tree's spread) where you'll plant the trees. To make mounds, mix equal parts soil from other areas of the yard with compost. If you bring in topsoil of a different texture, mix it into your own soil well.
You will also need to build raised beds if your soil is not deep enough for the trees' roots--at least 3 feet of soil for trees on dwarfing rootstocks, and at least 5 feet of soil for standard-size trees. If you think your soil is shallow, dig a hole or use a soil auger to the necessary depth. While digging, look for an abrupt change in soil texture. Watch for soil that suddenly becomes very clayey; this type of soil will restrict water drainage and root growth into the soil below. Although good soil drainage is one of the most important factors for fruit trees, soil texture will influence their growth. Loam soils, clay loams, or sandy loams are better for fruit trees than very sandy or heavy clay soils.
Different fruit tree rootstocks are adapted to different conditions. Some rootstocks tolerate clayey soils well and others withstand sandy soils. In general, peaches, sweet cherries, Japanese plums, and apricots do better in sandy soils; apples, pears, tart cherries, and European plums do better in heavier soils.
Have your soil tested, preferably the season before you intend to plant your trees. If necessary, add lime or sulphur to correct the pH to a range of 5.5 to 7.0, suitable for most trees. Add phosphate or potash fertilizers if phosphorus or potassium levels are low. All fruit plants will be healthier if the soil contains high levels of organic matter, so turning under a green manure crop or two before planting helps a great deal.
Plant nematode-susceptible stone fruits (peaches, plums, cherries, and apricots) where a grass cover crop or lawn grew for the previous 2 years. Two years without broad-leaved plants almost completely eliminates the most troublesome nematodes, root knot, and lesion, as well as verticillium wilt. Nematode- or verticillium-infected fruit trees are stunted and unproductive, and once infected, there is no cure. Many vegetables and small fruits are susceptible to verticillium wilt. Try not to plant fruit trees where susceptible plants have grown in the last 2 years. If you must plant stone fruits where vegetables grew recently, choose an area where corn has grown.
Have the soil tested for nematodes before planting. If high levels of root knot or lesion nematodes are found, plant the ground with a trap crop of marigolds, which will attract nematodes to their roots, the season before planting the fruit trees. Don't bother planting marigolds around the trees once they're set out to get rid of nematodes; you need to get nematode levels down before tree-planting time. Choose a marigold variety proven to be a good trap crop, such as 'Tangerine' or 'Nemagold' blend. Plant them 6 to 7 inches apart so they form a solid stand, and keep them weeded. In early fall, pull up the marigolds--roots included--and destroy them. Then plant a winter rye cover crop for additional protection against nematodes, and till it in early the next spring before planting trees.