Plum trees offer you the opportunity to enjoy the sweet fruit whenever you want. They can be grown in most sections of the United States, but do best when the annual rainfall ranges from 20 inches to 35 inches. They are, however, prone to early spring frost damage. Plums can be eaten in their whole form, and are commonly used in canning, cooking and jam making. Plum trees need well-drained soil, so clay soil can be challenging. Luckily, though, it is possible to amend the soil to support the needs of plum trees.
Choose a sunny location to plant the plum trees. Two are needed for cross pollination. Put the trees in the ground early in the spring, as soon as the soil dries out enough. Allow 20 feet of free space around each to allow for growth as they mature.
Rototill the clay soil to loosen it up. Dig at least 1 foot into the soil, spreading over a 10 square foot area. This will give the plum tree enough soil area to grow in. If you till a smaller area, the roots will become stunted when they hit the nontilled land.
Lay down 3 inches of compost. Work it into the top 6 inches of ground with the rototiller. Add 3 inches of sand on top and work it into the mixed soil. The sand and compost together will dry the soil out some and improve drainage.
Make the 10 square foot planting area at least 8 inches higher than the surrounding ground. Bring in additional clay, compost and sand if necessary. Raising the bed with further improve drainage.
Create a boundary to keep the soil mixture in place. Place four wood boards around the area, nailing them together to make a large planting box.
Put the roots of the bare-root tree in a bucket of water for two hours. This will keep them hydrated.
Dig a hole that is twice as large as the rootball. Make it as deep as it was while growing in the nursery. Cut off roots that are damaged or excessively long. Place the plum tree in the center of the hole and spread out the roots.
Fill the hole halfway with the removed soil. Water the soil to eliminate air pockets. Continue filling until the hole is level with the surrounding ground. Lightly tamp down the soil.
Tie the plum tree on at least two sides with twine or garden ties. Attach securely to stakes and push the stakes firmly into the ground. This will give the plum tree support as it grows.
Lay down 2 inches of mulch to preserve soil moisture. It will also keep weeds at bay.
Water plum trees with 1 inch of water per week. Feed young plum trees in April with food that has a 10-10-10 ratio of nitrogen-phosphorus-potassium. Scatter 1 cup of fertilizer over a 3 foot area around the tree trunk. Apply another 1/2 cup in June and again in August.