Learn About Plums
How to Sow
Plum: Bare Root or Potted Fruit Plant
How to Plant
Planting Bare Root Plants:
- Choose a site in full sun in an area with well-drained soil with a pH of 6.0-7.0. Make sure there is some protection from the prevailing winds. Northern exposures are less prone to late spring frosts, and are more likely to have more snow cover. This protects the plants from soil heaving in winter. Do not plant in the root zone of black walnut trees. Avoid heavy clay soil as well as sandy soil. Amend as needed with organic matter.
- Some plum trees need to be cross pollinated with another variety, some are self-fruitful; be sure to check your variety description. If your variety needs a pollinator, plant trees within 50 feet of each other.
- Space trees 12-18 feet apart.
- Plant dormant bare root plants in spring as soon as the soil may be worked.
- Soak the roots in water 1-2 hours before planting.
- Cut the tree back to approximately 30 inches tall at planting. Cut side branches back to 3-4 buds.
- The planting hole should be large enough to hold all the roots without bending or bunching up. Dig holes at least 18 inches deep and wide. Break up hard pan soil layers if present. Do not add raw fertilizers or manure to the soil mixture. Over feeding can kill young trees.
- Set the budded or grafted tree in the planting hole so that roots lie naturally, with the bud union 2 inches above the soil level after planting. Fill in the soil in layers and tamp down around the roots to make sure there is good soil to root contact and to remove air pockets.
- Water immediately to saturate all soil and roots in the hole. After the soil around the plant has settled, make sure the bud union is at the proper height above the soil level. Adjust as needed. Leaves should emerge 6-8 weeks after planting once the weather has warmed.
How to Grow
- When rainfall is not adequate, water newly transplanted trees deeply at least once a week during the first growing season. Apply 3-4 gallons of water per tree. Hoe a small ridge of soil around each tree to keep water from running off.
- A nitrogen fertilizer should be applied to newly transplanted fruit trees 3-4 weeks after planting. Be sure to keep granular fertilizers from direct contact with the tree trunk.
- Do not cultivate the soil surface within the area of the planting hole.
- Mulch 2-3 inches deep, extending 3-4 feet around the base of the tree, using shredded leaves or other organic matter.
- Use tree guards, cages, fencing or deer bags to prevent damage from mice, rabbits, deer and other wildlife.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
- Plums may be pruned to an open center, as peach trees, or for a central leader, such as apples. Remove dead and diseased wood.
- Plums ripen in late, July to September.
- Plums should be ripened on the tree. When you apply a gentle pressure to the fruit, if the skin feels soft, they are ready. They should separate easily from the tree with a little twist.
- Cool storage preserves them for winter enjoyment. Store in a humid and cool environment, 32-40 degrees F, in a perforated plastic freezer bag. The refrigerator is the ideal place but any cool area of the house will do. Bring them out to ripen at room temperature when ready for use.
Common Pests and Problems
Common Disease Problems
Bacterial Canker: Gummy, water-soaked cankers appear on branches and the trunk. Fruit develops with dark, sunken areas. This causes them to be more susceptible to brown rot. Cool, wet weather promotes development of cankers after blooming. Burpee Recommends: Cut out diseased wood. Contact your Cooperative Extension Service for recommendations.
Bacterial Leaf Spot: First signs are small translucent spots with a broad yellowish edge that slowly enlarge and become angular or irregularly circular with a reddish center. It thrives in cooler temperatures. The disease may also affect and disfigure flower heads. Burpee Recommends: Remove infected plants. Rotate crops with plants in a different family. Avoid overhead watering. Do not work around plants when they are wet.
Black Knot: Twigs and branches exhibit hard black knobby growths. This eventually girdles and kills branches. Burpee Recommends: Cut out diseased wood. Contact your Cooperative Extension Service for recommendations.
Crown Gall: This is caused by a bacteria and causes galls (masses of plant tissue) to form on roots, root crowns, stems and branches. The galls can interfere with the ability of water to move through the tissue, affecting plant vigor and causing stunted plants. Burpee Recommends: There is no cure for this disease; remove and destroy infected plants. Do not divide or propagate infected plants.
Scab: Dark spots form on leaves and fruit. Water soaked lesions gradually turn brown in the center with a lighter colored margin. Cracking on the fruit can occur. Burpee Recommends: Contact your Cooperative Extension Service for recommendations.
Common Pest and Cultural Problems
Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.
Leafhoppers: Leafhoppers cause injury to leaves and stunt growth. They also spread disease. Burpee Recommends: Remove plant debris. Use insecticidal soaps. Consult your Cooperative Extension Service for other insecticide recommendations.
Lygus Bugs (Tarnished Plant Bug): Lygus bugs are ¼ inch long and are green or brown with yellow markings. Nymphs are flightless and smaller than the adults. They suck on stem tips and flower buds and inject a toxic that deforms roots, stems and ruins flowers. Burpee Recommends: Because lygus bugs over winter in garden debris, remove all debris after the first frost. Contact your Cooperative Extension Service for insecticide recommendations.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Do I need two different plum varieties for cross pollination? Some varieties need two varieties for cross pollination and some are self-fruitful. Check your specific variety to see if you need a pollinator.
When will my tree bear fruit? Trees should bear fruit in 3-4 years, with full fruiting in 5-7 years.
Can I grow plum trees in my zone 10 garden? No, unfortunately plums requirecold winter temperatures and are not recommended in warmer zones than zone 8 or 9.