How to Grow Plum Trees

Acclimating Bare-Root Trees

Allow your tree’s roots to soak in water an hour or two before planting. Do not soak the roots for more than 24 hours.

Bare-root trees are not grown in a pot and will not have any soil around their roots – hence the name “bare root”. Our bare-root trees are shipped dormant, which helps them to transplant well and experience less transpiration (water loss) immediately after planting. The best thing you can do for a new tree is to avoid shock as much as possible, so don’t wait until it’s too late in the season to plant. The best time to plant a bare-root tree, or any other bare-root plant, is in the fall or early spring.

Acclimation Steps for Potted & Bagged Trees

If your new plants or trees from Stark Bro’s arrive in a pot and already display tender leafy growth, then they were likely grown in our greenhouses. Here are a few steps we recommend you follow to acclimate these plants and trees (or harden them off) before planting outdoors:

• Upon arrival, unbox your plants and trees, and keep them in the pots or grow bags they arrived in. Place them in a sheltered, semi-shady spot outdoors – like on a back porch. After a day or so, move them to a sunnier spot. Water your plants upon arrival, but then allow the top of the soil to dry out – this also contributes to the hardening-off process.
• Observe foliage – if signs of leaf injury appear prior to planting, move those plants or trees back into more filtered sunlight and an area protected from harsh winds. Air movement in outdoor conditions is equally important for hardening off the plant. Cool air helps harden the tender new growth but do bring plants back indoors at night if temperatures are expected to reach close to or below freezing.
• After 2-3 days of acclimating your plants and trees, and if the weather conditions are right, your new plants and trees are ready to be planted outdoors in a permanent location. Your new plants and trees should be able to manage conditions, as long as soil temperatures are expected to stay above 50ºF. For best results, try to plant on a cloudy day.

Please note: these are general recommendations. Your particular growing environment might require a slight variation on these guidelines since some plants can take more time (or less time) than others to harden off. Factors like the current year’s weather, individual plants, and your location may affect the process. If conditions outdoors are too harsh, keep potted plants near a sunny window, water them, and take care of like a houseplant. Then start the process of hardening off your plants.

Cross-Pollination

Is a pollinator variety present? Cross-pollination by a different variety, of the same type of tree, is key to the success of many fruit trees. In most cases, its absence is why trees don’t bear fruit or produce poorly. Since insects and wind carry pollen from one blossom to the other blossoms the trees should be planted fairly close together, within 100 feet.

Sun and Good Soil

Your tree would love a sunny place with well-drained, fertile soil. But it will be quite satisfied with six to eight hours of sunlight. Good drainage is required to keep your trees “happy.” If your soil has high clay content, use our Coco-Fiber Potting Medium or add one-third peat to the soil at planting time. We do not recommend planting fruit trees in heavy, pure clay soils.

Even if your yard isn’t the most ideal location, take heart. Fruit trees are very adaptable and respond well to fertilizers, so they can get along well even where the soil is nutritionally poor. Just steer clear of sites with extremely heavy soils or very poor drainage.

Surroundings

If you’d like your tree to become a landscaping asset, choose the planting place with this in mind. Imagine it as a full-grown tree and check everything out: Wires overhead? Sidewalk underneath? Does it obstruct something you want to see? Can you keep an eye on it from the house? Will other trees be in the way, allowing for their additional growth in the meantime?
Even a year or two after planting, your tree will be very difficult to transplant. So take the time to plant it in just the right place.

Space Wisely

First-time fruit tree growers often ask about recommended planting distances from patios, sewer lines, water pipes and so on. Ordinarily, patios will not be a problem because the soil beneath them will be dry and compacted. Therefore, the roots will not grow into this area as much. It’s still recommended, however, that you plant at least 8-10’ away from patios, water pipes and sewer pipes. You might not expect sewer and water lines to be affected since they are buried so deeply. But, since sewer and water lines tend to be wet, roots will grow to them and around them if the tree is planted too close. By planting your trees far enough away from these items, you can avoid this problem.

Space for Future Plantings

Once you’ve found out about fruit growing goodness firsthand, you’ll want to expand your home orchard. It’s important to plan for tree spacing so that the future growth areas will be ready when you are.

Spacing between trees:

Dwarf, 8-10'
Semi-Dwarf, 12-15'
Standard, 18-20'

Fruit trees require fertile soil for good growth, so before you plant, check your soil pH. Contact your local County Extension Office for information about soil testing in your area, or purchase one of our digital meters for quick and accurate results. If the soil pH where you plant your tree is 6.0-7.0, you’re in good shape. Take a look at the established trees and plants around the site. If they look healthy and are growing well, just follow the recommended fertilization program for your fruit trees. Steer clear of soils that are extremely heavy or poorly drained.

Planting Steps

• Before planting: soak tree roots in a tub or large trash can of water for one to two hours to keep its roots from drying while you dig. Do not soak more than six hours. DO NOT expose roots to freezing temperatures while planting.
• Dig the hole deep and wide enough so the root system has plenty of room. (Keep the topsoil in a separate pile so you can put it in the bottom of the hole, where it’ll do the most good.)
• Roots grow better in soil that’s been loosened, so mix in our Coco-Fiber Potting Medium into your pile of topsoil. You can also use dehydrated cow mature, garden compost or peat moss (up to 1/3 concentration).
• Fill the hole, putting the topsoil back in first. You can avoid creating air pockets by working the soil carefully around the roots and tamping down firmly.
• Create a rim of soil around the planting hole 2” above ground level. This allows water to stand and soak in. (In the fall, spread soil evenly around tree to prevent damage from water freezing around the plant.)

Post-Planting

• Water your new tree. Deep, thorough soaking is best, with a solution of Stark® Tre-Pep® Fertilizer. (If planting in the fall, wait to fertilize until spring for best results.) This effective starter fertilizer helps trees and plants grow quickly and vigorously. After watering, if soil compacts, be sure to add enough soil to fill the hole to ground level.

Grafted Trees

Grafted trees need special planting attention. All Stark Bro’s fruit trees are grafted or budded, the only methods for growing true-to-name planting stock. You can see where the fruiting variety on top is joined to the root variety on the bottom by a bump in the bark, change in the bark color or a slight offset angle. For certain dwarf trees, it’s very important to keep this graft above the ground. Otherwise, roots could develop from above the graft; then your tree could grow to full size by bypassing its dwarfing parts.

Most Stark fruit trees are budded to specially selected clonal rootstocks. For dwarf, semi-dwarf and colonnade apple trees, the bud union should be planted 2-3” above the soil line. Standard size apple trees as well as our Custom Grafted trees should be planted 1-2” deeper than the soil lines from the nursery row.

For dwarf pears, peaches, nectarines, apricots, cherries and plums trees the bud-graft line should remain at or above the ground and for standard size trees they will do better with a slightly deeper planting.

Potted Trees

Stark trees that are grown and shipped in bottomless pots are part of our continuing quest for producing better and stronger trees for the home grower. By following these simple instructions, you will be assured of getting your young tree off to the best possible start.

• Before planting: When your tree arrives, carefully take it out of the package, making sure not to damage any of the branches. The potted tree has been watered prior to shipment and should arrive moist, but it does need another drink when it arrives at your home. Be sure the container is moist clear through. If you can’t plant your tree immediately upon arrival, keep the pot moist until you can plant it and keep the tree in a sheltered location. DO NOT place your potted tree in a bucket of water. This could cause the roots to rot, and kill your tree.
• Your tree is ready for planting as soon as it arrives at your home. Then, simply grasp the sides of the container and carefully slide the tree out. The potting soil should remain intact around the tree’s roots. You will want to keep this soil with the tree and plant it, soil and all, into the prepared hole.
• Fill the hole with soil and water thoroughly with a solution of Stark® Tre-Pep® Fertilizer.
• Your potted tree may have come with a bamboo stake, which helped straighten the baby tree as it grew in the pot. We recommend that you keep the tree staked when you plant the tree, as we recommend staking for all young trees of any type. You may remove the stake and replace it with a different style if you prefer. Tree Stake, the perfect strapping system for Stark Bro’s trees, comes with a sturdy fiberglass rod, and a revolutionary flexible strapping system that allows for movement and growth, available from Stark Bro’s.

One final point: Please be sure to remove the name tag from your tree. As the tree grows, this small piece of plastic can choke off its circulation, damaging or killing the tree. If you’d like to keep the tag on your tree, retie it loosely with soft twine.

When To Prepare Your Soil

Soil preparation can be done at any time that the ground is not too wet or frozen. Your trees may be planted even when temperatures are quite cool. If a hard frost is expected, it is advisable to delay planting for a while until temperatures become more moderate. Generally, as long as your soil is workable, it is fine to plant.

How To Prepare Your Soil

• Roots grow faster when they’re spread out. Dig the hole deep and wide enough so the root system has plenty of room to easily expand. Keep the topsoil in a separate pile so you can put it in the bottom of the hole, where it’ll do the most good.
• To loosen the soil, mix dehydrated cow manure, garden compost or peat moss (up to 1/3 concentration) into your pile of topsoil. Make sure the peat moss you get is either baled sphagnum or granular peat. You can also add our Coco-Fiber Potting Medium or 2 or more inches of organic material and work in evenly with the existing soil.
• Your lawn can provide you with ideal organic materials such as grass clippings and shredded leaves. Not only will the grass and leaves break down to provide soil nutrients, but they will help loosen the soil as well. You can gather these in the fall with spring planting in mind.

Common soil amendments:

• compost
• sand
• manure
• lime
• peat moss

Adding organic materials, such as our Coco-Fiber Potting Medium and compost will improve most every soil type. Organic materials bind sandy soil particles so they retain moisture and nutrients better. They also break apart clay and silt particles, so that water can infiltrate and roots can spread.

Soil Types

• Clay and silt soils are made of very small particles. They feel slick and sticky when wet. Clay and silt hold moisture well, but resist water infiltration, especially when they are dry. Often puddles form on clay or silt soils, and they easily become compacted.
• Loam soil is a mix of sand, silt or clay, and organic matter. Loam soils are loose and look rich. When squeezed in your fist, moist loam will form a ball, which crumbles when poked with a finger. Loam soils normally absorb water and store moisture well. Loam soils can be sandy or clay based, and will vary in moisture absorption and retention accordingly.
• Sandy soils contain large particles that are visible to the unaided eye, and are usually light in color. Sand feels coarse when wet or dry, and will not form a ball when squeezed in your fist. Sandy soils stay loose and allow moisture to penetrate easily, but do not retain it for long-term use.

About Fertilizers

• Fertilizers – both synthetic and organic (naturally derived) – are soil amendments labeled with a “guaranteed analysis” of nutrients like Nitrogen (N), Phosphate (P), and Potash (K).
• Alternately, there are organic soil amendments, like compost and aged/rotted manure. They are used like fertilizers, but they are not technically fertilizers. You can make your own organic soil amendments, like compost, out of food or garden scraps, or even get compost, manure, and other organic soil amendments from a trusted local source. While these help add nutrients to the soil to support your plum trees, they will not have a “guaranteed analysis” value.
• In general, plum trees thrive when macronutrients like Nitrogen (N), Phosphorous (P), and Potassium (K) are present. Nitrogen helps encourage vegetative growth (leaves and branches). Phosphorus encourages root and blossom development. Potassium/Potash is responsible for the efficacy of the plum tree’s natural disease-resistance and systems supporting its overall health, kind of like an immune system. A water-soluble fertilizer that is specifically formulated for use on young plum trees provides the nutrients these trees take in during their initial years in the ground as they become established.

Take care not to over-fertilize, or you may produce a tree that is unbalanced, which can affect fruit production and leave the tree susceptible to pests and disease.

Macronutrients

Nitrogen, phosphorus/phosphates, and potassium/potash are the “big” macronutrients plum trees need to grow normally. They are present in healthy soil, but may be added when soil is deficient. Nitrogen is the nutrient most used by growing plum trees; it moves throughout the soil, is leached off by normal growth and must be replaced by synthetic or organic compounds. The main source of nitrogen is decaying organic matter. Signs of macronutrient deficiency in plum trees include reddish or pale colored leaves, narrow or shrunken leaves and dead spots on leaves.

Micronutrients

Plum trees also need micronutrients in the soil, which help make the macronutrients available to the tree. For example, molybdenum helps fix nitrogen to the soil. Copper and zinc prevent color mottling and misshapen leaves. Calcium is another essential micronutrient that plum trees thrive on that improves leaf and fruit quality. The easiest way to add micronutrients is by adding aged compost or a good, balanced fruit tree fertilizer that states micronutrients are part of the formula.

When to Fertilize Plum Trees

• In nutrient-rich soil, you can withhold using fertilizers until your plum trees begin bearing fruit (average: 2-4 years after planting). If your new plum trees don’t put on several inches of new green growth during the growing season, consider fertilizing starting the following spring.
• Typically for plum trees, you can start fertilizing after bud break, but by no means any later than July. For any specific fertilizer application instructions, always refer to the information printed on your product’s label. Be mindful that local advisories on fertilizing may be in effect during certain times of year. For the sake of your local environment, please adhere to these restrictions.
• Many fruit trees require more nitrogen after they start bearing fruit. Each year, test the soil to see what it needs, and if the nitrogen levels appear low, then apply a low-nitrogen fertilizer in small amounts a couple of weeks before bud break in early spring. Mulch your trees and keep weeds at bay, since weeds will compete with your plum trees for nutrients.

To prevent the chance of injury as the growing season winds down, do not fertilize past July 1st.

Read more about fertilizing:

• How to Fertilize New Fruit Trees
• How to Fertilize Mature Fruit Trees
• When to Stop Fertilizing & Why

Crown Gall

Trees appear stunted and slow growing; leaves may be reduced in size, little or no fruit. If tree is dead, inspect roots for hard, woody ‘tumors’. Note: many things can cause stunted trees.

Control

• Consult County Extension Agent

Bacterial Canker

Appears on branches and trunk as gummy cankers and water-soaked areas. Fruit develops dark, deeply sunken areas, causing them to be more likely to get ‘Brown Rot’. Cool, wet weather after blooming favors development.

Control

• Consult County Extension Agent

Black Knot

Appears as hard black knobby growths on twigs and branches. Will eventually girdle and kill branches.

Natural Control

• Prune out and burn.

Scale

Usually on bark of young twigs and branches, encrusted with small (1/16”) hard, circular, scaly raised bumps with yellow centers, may also be on fruit. Sap feeding weakens the tree.

Natural Control

• Monterey Horticultural Oil
• Monterey Fruit Tree Spray Plus

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Tarnished Plant Bug

Yellow-brown winged insect may have black spot or red stripes. Injects toxins into the buds and shoots causing ‘dwarfed’ shoots and sunken areas (cat facing) on fruit.

Natural Control

• Monterey Fruit Tree Spray Plus

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Leafroller

Pale yellow or ‘dirty’ green worms. Leaves are rolled and webbed together where insects feed. Eventually becomes skeletonized.

Natural Control

• Hi-Yield® Vegetable & Ornamental Insect Control

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Aphids

They are the size of a pinhead and vary in color depending on the species. Clusters on stems and under leaves, sucking plant juices. Leaves then curl, thicken, yellow and die. Produce large amounts of a liquid waste called “honeydew”. Aphid sticky residue becomes a growth media for sooty mold.

Natural Control

• Monterey Fruit Tree Spray Plus

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Brown Rot

Fruit turns brownish with lighter spots. Quickly becomes soft, rotten and unusable.

Natural Control

• Monterey Fruit Tree Spray Plus
• Fall clean up of all fruit and debris.

Chemical Control

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide
• Hi-Yield® Captan 50W Fungicide

Bacterial Leaf Spot

Appears on the undersides of leaves as black or brown spots. Often the center falls out leaving a hole with a red halo. The leaves may turn yellow and fall. Fruits also get spots, sunken areas & cracks.

Control

• Consult County Extension Agent

Green Fruitworm

Bluish-gray moth. Larvae are 1’ long, usually green or brown with white sports and body stripes. Feeds on young leaves and young fruits. Disfigures the fruit.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Plum Curculio

Adult is brownish-gray 1/5” long, hard-shelled beetle with long snout and 4 humps on back. Cuts a crescent shaped hole under the fruit skins and lays eggs. Worms hatch and tunnel into fruit. Premature dropping of fruit can occur.

Natural Control

• Post harvest clean up.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Oriental Fruit Moth

Gray moth, 1/2” long. Larvae are white with a brown head, 1/2” long. Larvae burrow into twigs and fruits.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Cherry Fruit Fly

This fly is very similar to Apple Maggot. Adult similar to housefly but smaller, larvae are yellowish-white worms. Eggs lay under fruit skins, larvae tunnel making railroad pattern. Small pinpoint sting marks visible on fruit.

Natural Control

• Hi-Yield® Vegetable & Ornamental Insect Control

Mites

Pinpoint size, many different colors. Found on undersides of leaves. Sap feeding causes bronzing of leaves. Severe infestations have some silken webbing.

Natural Control

• Monterey Fruit Tree Spray Plus
• Monterey Horticultural Oil

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Rose Chafer

Beetle has ½“ long, tan wings with reddish-brown edges. Long, thin hairy legs. Skeletonizes leaves and flowers. Present in large quantities in June & July. Worst on sandy sites near grassy areas.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Borers

Appears as a thick, gummy substance (sap) leaking from round holes on the trunk or in a crotch of the tree. Worms with brown heads and cream-colored bodies tunnel thru trunks that will kill the tree.

Natural Control

• Hi-Yield® Vegetable & Ornamental Insect Control
• Use a fine wire to try and mash or dig them out.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Japanese Beetle

Adult is a metallic green beetle. It skeletonizes leaves. Larvae are a grub, which feeds on turf roots. Check turf product labels for timing of control of grubs. This is more of a problem east of the Mississippi river.

Natural Control

• Hi-Yield® Vegetable & Ornamental Insect Control
• Traps

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Powdery Mildew

Whitish-gray powdery mold or felt like patches on buds, young leaves and twigs. Leaves may crinkle and curl upward. New shoots are stunted. Over winters in fallen leaves.

Natural Control

• Monterey Fruit Tree Spray Plus

Leafhopper

Various colors and similar to aphids this small, active, slender-winged insects are usually found on the underside of leaves. Retard growth, leaves become whitened, stippled or mottled. Tips may wither and die. This insect carries virus of certain very harmful plant diseases.

Natural Control

• Monterey Fruit Tree Spray Plus

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Thrips

Tiny, slender, fringed wing insects ranging from 1/25 to 1/8” long. Nymphs are pale yellow and highly active and adults are usually black or yellow-brown, but may have red, black or white markings. Feed on large variety of plants by puncturing them and sucking up the contents.

Natural Control

• Monterey Fruit Tree Spray Plus
• Hi-Yield® Vegetable & Ornamental Insect Control

Coryneum Blight

Small reddish-purple spots appear on young leaves then enlarge and eventually dropping out of the leaf blade leaving a “shot hole.” It appears on fruit, usually in clustered as light brown spots or lesions with dark purple margins.

Natural Control

• Monterey Fruit Tree Spray Plus

Chemical Control

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide

Scab

Spots on young leaves are velvety and olive green turns black; leaves wither, curl and drop. Fruit also has spots, is deformed, knotty, cracked and drops.

Chemical Control

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide

Leaf Curl

Leaves become thickened, puckered and twisted with a reddish-purple color along puckered areas. Turn yellow and drop, may completely defoliate and causes weakening of tree. Any remaining dead leaves should be removed in the fall and all debris removed from the area.

Chemical Control

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide

Blotch

Fungus disease that is spread by rain in spring and early summer and can appear as early as 2-3 weeks after petal fall. Patches of dark green to black, circular or irregular in shape, may merge together to cover a large area of the fruit surface. Sometimes it can be rubbed or washed off, but may leave a brown discoloration on fruit. Little damage is done to the flesh.

Natural Control

• Prune for air and light, clean up fallen leaves and fruit.

Survival

When your tree is dug up from our fields to be shipped to you, the root ball loses many of its tiny feeder roots, which are needed to absorb moisture and nutrients. Pruning helps balance the top growth of your tree with the root system, giving the roots time to re-establish in your yard before spring growth.

When your Stark Bro’s bare root tree arrives, our professionals have already pre-pruned your tree for you. Because of this, you DO NOT need to prune them again when you plant. The only pruning done at this time would be any broken branches or roots.

Plan to prune your fruit trees during every dormant season. In Zone 6 and farther north, you should wait until late winter. A good reference book, such as Pruning Made Easy, can be invaluable for answering questions and guiding you through the pruning process.

Stimulation

• In addition, cutting the tree back stimulates stronger, more vigorous growth from the remaining buds. After a single growing season, a tree you prune will be bigger than a matching unpruned tree.

Shaping

• Even more important, your fruit tree needs to be shaped. The natural shape of a fruit tree is not always the best for maximum fruit production. Trees you receive from Stark Bro’s have been pruned in the nursery row for proper shaping, but correct pruning must continue at home. If you keep up with your pruning and shaping each year, you’ll make mostly small, easy-to-heal cuts.

Pruning Tips from the pros:

10 o’clock pruning angle.

• Narrow, V-shape crotches are an open invitation to disastrous splitting later on, particularly when your tree is ripening with a large bumper crop. For your branches: choose wide 10 o’clock and 2 o’clock angles.

Pruning to a bud.

• Make sharp, clean cuts close enough so that you won’t leave a clumsy stub that’s hard to heal over. Stay far enough above the bud so it won’t die back. Slant the cuts and the new growth will develop beautifully.
• Always prune back to buds aimed in the direction you want limbs to grow. Every branch has buds pointed in various directions. Since you want vigorous new growth to spread away from the center of the tree, make your cut above a bud that’s aimed outward. This helps your tree grow into a spreading shape.

Prune For Success

Fruit trees develop better if they’re pruned at the right times in the right ways. Here’s how:

Help the tree form a strong framework.

Remove weak, diseased, injured or narrow-angle branches, the weaker of any crossing or interfering branches, and one branch of forked limbs. Also remove upright branches and any that sweep back toward the center of tree. You want to keep your tree from becoming too thick and crowded; some thinning is necessary to permit light to enter the tree and to keep its height reasonable. All these objectives promote improved bearing, which is your overall aim. You’ll be pleased with the results.

Prune Japanese Plum Trees to a Vase Shape.

Select and maintain three to five main scaffold limbs arising from the trunk to control the shape of the tree. These limbs should point in different directions and originate no less than 18” and no more than 36” from the ground, balancing growth evenly between the scaffold limbs. Those branches remaining in the center above the primary scaffold branches or any growth below the scaffold branches should be cut off. Any growth arising on scaffold branches within 6” of the trunk should be removed.

If for some reason the primary scaffold branches could not be selected the previous season, they may be chosen at this time. All branches above or below the scaffold branches should be removed. Avoid cutting (heading) the main scaffold branches unless necessary to maintain balance in the tree. If one scaffold branch dominates the tree, it should be headed back to a size proportionate with the others. It is necessary to have all scaffold branches growing at approximately the same rate to maintain a well-balanced tree.

Prune European Plum Trees to a Central Leader Shape.

European Plum trees do best when pruned and trained to a central leader tree. This type of tree has a pyramidal shape with a single upright leader limb as its highest point. This leader is the newest extension of a long, upright growing trunk from which all lateral branches arise. As with all strong growing branches, the leader should be headed at approximately 24-30” above the highest set of scaffolds branches. The uppermost bud on the leader produces a vigorous new leader, and no other shoot should be allowed to grow taller. Lateral limbs should be selected from shoots growing out from the central leader. These should be spaced vertically 4-6” apart, have growth that is more horizontal than vertical and point in different compass directions from the trunk. Any unbranched lateral branches should be headed back by approximately ¼ of their length to encourage side branches and to stiffen lateral branches. All laterals should have a wide branch angle.

Pruning Whips (Unbranched Trees)

Prune back to 28-36” above the ground at planting time. After the new branches have grown 3-5”, select a shoot to become the leader and scaffold limbs.

Off-season pruning

Sometimes pruning needs to be done even when the season isn’t the best. If a branch is broken by the wind or by a heavy load of fruit, emergency treatment is necessary. Prune back the ragged edges; making a smooth cut that leaves no stubby stump. Fast-growing “water sprouts” can be removed as soon as you see them rather than waiting until winter.

Fruit Thinning

There are several reasons to thin fruit:

• To reduce limb breakage
• Increase fruit size
• Improve fruit color and quality
• Stimulate floral initiation for next year’s crop

Home gardeners thin fruit trees by hand. During May and June, many fruit trees will drop or abort fruit. This is a natural process that allows the tree to mature the crop load.
Trees may bear biannually, that is bear fruit every other year, bear heavy one year, then light the next year. Thin the heavy crop to correct bearing habit.

Japanese Plum Trees

The best time to thin Japanese plum trees is when the fruit is large enough to be easily picked. Space plums 4 to 6 inches apart on the branch and break up clusters.

Before you begin, read and follow all instructions on labels.

General Maintenance

Natural Control

• Serenade® Garden Disease Control for leaf spot and powdery mildew.

When To Spray

Dormancy (late winter/early spring before bud break)

• Monterey Horticultural Oil for scale insects and mites.

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for leaf curl.

Budbreak

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for brown rot, shothole and scab.

Full Bloom

• Hi-Yield® Captan 50W Fungicide for brown rot.

Growing Season

• Monterey Horticultural Oil for scale insects and mites.

At the First Sign of:

• Hi-Yield® Vegetable & Ornamental Insect Control for borers, leafrollers, fruit flies, Japanese beetles and thrips (not for use on large trees).

• Monterey Fruit Tree Spray Plus for scale insects, plant bugs, aphids, brown rot, mites, powdery mildew, leafhoppers, thrips and blight.

• GardenTech® Sevin® Concentrate Bug Killer for scale insects, leafrollers, aphids, mites and borers (not for use on large trees).

• GardenTech® Sevin® Concentrate Bug Killer for scale insects, plant bugs, leafrollers, aphids, green fruitworm, plum curculio, oriental fruit moth, mites, rose chafer, borers, Japanese beetle and leafhoppers (not for use on large trees).

General Guidelines

• If summer brings about an inch of rainfall every 10 days or so, you won’t need to use the hose. But if it gets really dry, you can give your new tree a good, thorough soaking. The best way to do this is to let your garden hose trickle slowly. This gives the water a chance to soak in instead of running off. You can also use a soaker hose to water several trees at once. Give your tree enough water to soak the ground all around the roots.
• It’s important to note that even if you’re in the midst of a brown-lawn drought, you don’t want to water too much. Once every 10 days or two weeks is plenty. Worse than dry, thirsty roots is waterlogged, drowning roots.
• Although a little depression in the soil aids summer watering, it’s important to bring the soil around the tree up to the level of the surrounding soil for the winter. If not filled in, water could freeze around the trunk and injure the tree.

Plum, pluot and plumcot trees will start bearing fruit in 3-6 years under normal growing conditions with proper maintenance and care.

When to Harvest

Make sure to wait until just the right time to pick your fruit. Plums are ready to be picked when they separate easily from the tree with a little twist. They should not be picked when firm.

Harvest European plums when dead ripe.
Japanese plums are picked when they begin to soften.

Harvest Seasons and Expected Yield

European Plums

Harvest season begins July thru September depending on the variety and location. Annual average yield per tree:

• Dwarf, ½-1 bushel
• Standard, 1-2 bushel

Japanese Plums

Harvest season begins mid-July thru early September depending on the variety and location. Annual average yield per tree:

• Dwarf, 3-4 bushels
• Semi-dwarf, 4-5 bushels
• Standard, 5-6 bushels

Plumcots

Harvest season begins June depending on the variety and location. Annual average yield per tree is 3-4 bushels.

Storage

Cool storage preserves them for winter enjoyment. Fresh fruit is a special treat during the bleak winter months. Fortunately, many varieties of fruit keep their fine eating qualities for a long time with proper storage. If you’re planning to store them, pick them a bit early, just as they start to ripen. Handle them carefully to avoid bruises that could develop into spoilage.

The ideal storage spot is humid and cool, from 32-40°F. Place them in perforated plastic freezer bags and keep them in any cool place. A refrigerator is the idea storage spot but any cool area in your house, the basement or an unheated porch might also be fine for a while. Bring them out to ripen at room temperature when you’re ready to use them.

It’s best to inspect stored fruit every week or so to check for any spoilage. That way, you can remove any that are developing soft spots or brown areas. This keeps spoilage from “spreading” to nearby fruit. Remember, “One bad apple spoils the whole barrel.”