How to Plant a Flowering Plum Tree

Flowering plum trees (Prunus spp.) are generally hardy between U.S. Department of Agriculture plant hardiness zones 3 to 10, depending on species. They require a certain number of chilling hours in the winter, though, with temperatures between 32 and 45 degrees Fahrenheit, in order to bloom and set fruit. When growing a flowering plum in a southern mild-winter climate, select a species or cultivar that has a low chilling requirement.

Select a sunny spot for the flowering plum, if possible, where it will get at least six hours of sunlight each day. If there isn’t a spot in the yard where it will get this much sun, choose a flowering plum species or cultivar that will thrive in partial shade, with four to six hours of sunlight. American plum (Prunus americana, hardy in USDA zones 3 to 8) grows fine in partial shade. A full-sized flowering plum should be planted at least 12 feet away from other trees or structures. A smaller, dwarf flowering plum should be planted 10 feet away.

Soil with a pH of 5.5 to 6.5 is preferred by flowering plums, but there are species that do fine in soil that is more acidic or alkaline. Test the soil to determine the pH before purchasing the tree. Soil test kits are available at garden centers. Rather than trying to adjust the soil pH to suit the tree, choose a species that will grow in the existing pH. It is difficult to adjust the pH of soil and maintain that pH over the entire root zone for the life of the tree. Blireana flowering plum trees (Prunus x blireana, USDA zones 6 to 8) grow well in highly acidic, neutral or highly alkaline soil.

Flowering plums prefer sandy loam soil, but there are species and cultivars that will grow in clay, sandy or loamy soil. Select a flowering plum that will thrive in the existing soil. All flowering plum trees require fast-draining soil, though.

Check how quickly the soil drains by digging a hole that is 1 foot wide and 1 foot deep. Fill it with water, wait for the water to drain and then fill it again. If it drains within 2 hours the second time it is filled, a flowering plum will do fine. If it takes longer than that, find a different planting site that drains more quickly.

Flowering plum trees sold in containers or with a balled and burlapped (B&B) roots can be planted at any time of the year. However, fall is the best time to plant all flowering plums, including those sold with bare roots. In northern, cold-winter climates, plant them right after the deciduous trees have dropped their leaves. In southern, mild-winter climates, flowering plums are best planted in December or January.

Dig the hole for the flowering plum at least twice the size of the rootball. When the soil is heavy clay, a wider planting hole, even up to five times the width of the rootball, is better. The loosened soil around the rootball will make it easier for the tree to get established. Scratch the sides of the hole with a hand rake if the soil is clay. Dig the hole just deep enough for the flowering plum to be planted at the same depth it was growing or 2 to 4 inches higher. Break up any clumps in the backfill soil and mix in some organic matter like well-aged manure, composted pine bark mulch or compost. The final backfill soil should contain 10 to 20 percent new organic matter. Mix it into the soil thoroughly by hand or with a dirt shovel.

Take the flowering plum tree out of its container or plastic wrap. If it is a B&B tree, and the covering is actual burlap, it can be planted with the burlap left on. Just remove any wires or ties, gently pull the burlap down off the top of the rootball and leave it in the bottom of the hole. It will decompose without harming the tree roots.

Check the rootball of a B&B or container-grown plum tree for encircling roots. Bare root plum trees do not grow encircling roots. Use a sharp knife or hand pruners to cut them a few inches from the trunk. Otherwise, they will keep growing around the root mass until they strangle the tree. Sterilize the knife or pruners with household disinfectant, then rinse and dry them before using. If the flowering plum tree was growing in a container and became pot bound with tightly packed roots, use a sterilized knife or pruners to make several 1- to 2-inch deep vertical cuts around the root mass. Loosen the roots with your fingers.

For bare-root trees: Build up a hill of soil in the center of the hole and set the tree in the hole with the roots dangling down around the hill. Fill the hole in around the flowering plum tree roots until it is half full. Gently tamp down the soil then finish filling the hole. Plant them at the same depth they were growing before they were dug; the trunk will be darker where the soil was before it was dug and lighter right above the previous soil line.

For container or B&B trees: The top of a container-grown or B&B flowering plum tree rootball should not be covered with soil.

Build up a 3- to 4-inch-high ring of backfill soil directly around the edge of the rootball, to create a ring for water.

Spread a 2- to 4-inch depth of organic mulch over the planting hole soil and the rootball but keep it a few inches away from the trunk. Wet mulch right up against the trunk encourages disease.

Water the flowering plum tree generously right after planting to settle the soil. Pour the water right over the rootball within the soil ring. Check the rootball every few days by sticking your fingers in a few inches. If it feels like it is beginning to dry, water the tree again. If it is still wet, wait another day or two. The rootball should be kept lightly moist for at least a few months after planting or until the ground freezes, but not dripping wet. A container or B&B flowering plum may have to be watered every day if it is planted in the spring or summer.