How to Grow Blueberry Plants

Acclimation Steps for Potted Plants

Things that may cause injury to tender new growth in transplants:

• temperatures (below 50ºF or above 90ºF)
• frost snaps
• strong/direct sunlight
• wind

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 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 plant, is key to the success of many plants. In most cases, its absence is why the plant doesn’t bear fruit or produces poorly. Most berry plants are self-pollinating, but for a larger fruit and crop plant more than one variety.

Sun and Good Soil

Your plant 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 plant “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 berries in heavy, pure clay soils.

Even if your yard isn’t the most ideal location, take heart. Most berries 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.

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 so that the future growth areas will be ready when you are.

Before Planting

Before you plant, check your soil pH. This can be done by contacting 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. Ideally, your blueberries need a soil pH between 4.5-5.5, but below 6.5 will work. To amend your soil, use a soil acidifier. Steer clear of soils that are extremely heavy or very poorly drained.

Spacing

• Depending on the variety what spacing you will need, high bush 4-6’ and low bush 2-4’ apart with 6-8’ between rows.

Planting Tips

• Don’t plant too deep. The crown should be right at the soil level, with the roots just under the surface.
• Blueberries should not be fertilized until the plants leaf out. Then use a solution of our Stark® Blueberry Special Fertilizer, formulated just for blueberries.
• If your berries are potted, plant them at the same depth as they were in the pot.
• Blueberries put down a shallow root system, so it is important to water thoroughly during summer, mulch heavily and keep soil acidic.

Container-Growing

Growing blueberries in a container is ideal for patios, decks or porches.

Planting Steps

• Fill the container with potting soil loosely (do not tamp) to 3” below the rim.
• Remove plants from growing/shipping containers.
• Gently loosen root system from the soil ball, so roots do not encircle the soil ball.
• Place plant so the root ball is even with the soil surface.
• Fill the container with the remaining soil.
• Water lightly until plant is well rooted. (After the initial watering, water the container as needed. The best way to determine if your container needs water is to check the soil by inserting your finger into it. If it feels dry, water your container. Because of soil porosity and drainage holes in your container, it would virtually be impossible to overwater your container.)

Container Placement

• Until the threat of frost has passed, keep your planter indoors in bright sunlight. When temperatures rise to 50 degrees or above, you can move your container plant outdoors to a sunny location. Plants should not be placed immediately in the full sun. An acclimation period of 2-3 days may be needed so as not to burn plants that were under-exposed to light during shipping. Acclimate to cooler air temperatures.
• The container may be brought back indoor to a sunny location before the temperatures fall below 50 degrees.

Additional Information

• Blueberries begin to produce fruit in the third season, so pruning is not required until then.
• Blueberries ripen over several weeks, so plan to pick more than once.
• Protect your crop from birds with a Garden Net.
• The average life of blueberry plants is 20 years with proper maintenance.
• Suggested number of plants for a family of 5: 8-10 (2 plants per person).

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
• soil acidifier
• 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.

Fertilizing Tips

• Excess fertilizer easily damages blueberries; allow for rain between applications.
• For new plants: wait until the first leaves have reached full size before fertilizing.
• Fertilize every 6 weeks (depending on rainfall) until mid-summer.
• For older plants: apply fertilizer when new growth begins in the spring.

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 Fruit Tree Spray Plus
• Monterey Horticultural Oil

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Stem Borer

Wilted tip on plants indicates a possibility of a little borer. If it breaks off readily, and is hollow, prune back branch until no longer hollow. Burn all pruning.

Control

• Consult County Extension Agent

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
• Natural Guard® Caterpillar Killer Spray w/BT

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Botrytis Blight

Gray, hairy mold decays blossoms, green and ripening fruit as well as harvested fruit.

Natural Control

• Monterey Fruit Tree Spray Plus

Red Leaf Gall

Bladder type enlargements of all or part of a leaf, white or pink and soft, turning brown and hard with age. Seldom serious, but in wet seasons in the south, the number of galls can be quite high, hand pick and destroy. This is more of a problem in the south.

Control

• Consult County Extension Agent

Powdery Mildew

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

Natural Control

• Fall clean up is essential.
• Monterey Fruit Tree Spray Plus

Brown Rot

Young growing tips wilt and dry just before blossoming. Fruits are yellowish, firm, leathery, turn dark and mummify.

Natural Control

• Clean up thoroughly in fall, hand pick all mummies.

Other Control Options

• Consult County Extension Agent

Mites

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

Natural Control

• Monterey Fruit Tree Spray Plus
• Monterey Horticultural Oil

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Aphids

They are the size of a pinhead and vary in color depending on the species. Cluster 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 growth media for sooty mold.

Natural Control

• Monterey Fruit Tree Spray Plus

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Lybus Bugs

Small oval insects, color range from pale green to reddish brown or black. Feed by sucking sap, signs of infection discoloration, deformed shoot and stems, curling of leaves and lesions.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Spittlebugs

Immature bugs are small green, soft-bodied and adults are small (1/4”) winged insect that feed on the plant sap. They are surround by a white mass that looks like spit. They suck on the sap, weakening the plants.

Natural Control

• Monterey Fruit Tree Spray Plus
• If infestation is small can be washed off with a hose.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Blueberry Maggot or Fruit Fly

Adults are similar to a Cherry Fruit Fly and Apple Maggot. The larvae will tunnel and lay their eggs in fruit, usually in ripe fruit. Prompt harvest is very necessary.

Natural Control

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

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Japanese Beetle

Adult is a metallic green beetle, which 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

• Traps

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Sawfly

Immature flies are soft-body with tiny legs. Adults are wasp like in general body shape and some have yellow and black markings or are entirely black. Larvae feed on leaves and spin a cocoon when fully grown.

Natural Control

• Monterey Fruit Tree Spray Plus (eggs)

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Thrips

Small insects, less than 1/2” long, with feathery wings, yellow to brown in color. Cause damage if they lay eggs in fruit soon after bloom, scarring the fruit. In summer they feed on new vegetative growth, and damage summer fruit (not usually considered a problem).

Natural Control

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

Weevils

Adults are hard-bodied, long snouts, usually dark colored. Feed on leaves, flowers and developing buds. Larvae are white grubs that live inside plant tissue; some live underground and feed on the roots.

Chemical Control

• GardenTech® Sevin® Concentrate Bug Killer

Mummy Berry

Flowers turn brown, new shoots are blackened in center and wither and die. As berries ripen they become cream to pale pink, then tan or whitish gray, then shrivel and harden.

Chemical Control

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

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

Gray Mold

The fungus thrives in cool, moist conditions. Usually begins on plant debris, weak or inactive plant tissue, than invades healthy plant tissue. Causes spotting and decay of flowers and foliage, tissue becomes soft and watery. Affected parts of plant could wilt and collapse. If humidity remains high a grayish-brown coating and spores develops over the surface of the collapsed tissue.
Good sanitation will help avoid the problem.
Remove and destroy dead leaves, flowers and dead plants.
Water the plants at soil level and not on foliage.

Chemical Control

• Hi-Yield® Captan 50W Fungicide

Anthracnose

New cankers appear on bark as small circular spots that are red or purple when wet. When they enlarge they become sunken orange to brown areas in the bark. As the cankers age, bark sloughs off exposing wood beneath, or disintegrates exposing fibers that give the area a ‘fiddle string’ appearance. Cankers usually do not grow larger after first year’s growth. Brown spots appear on leaves and fruit. At harvest the fungus can infect the fruit. Fruit lesions are circular, brown and sunken with gray or cream centers (Bull’s Eye rot). Disease rarely kills tree, usually confined to small branches and twigs.

Chemical Control

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide

Blueberries should be pruned during the winter while the bushes are dormant. In winter, flower buds are easily visible on one-year-old wood and their numbers can be adjusted by pruning to regulate the crop load for the coming year. Blueberries do not need to be pruned in the first year. Pruning should be moderately heavy in the second year.

Training Young Plants (1 to 3 years of age)

If vigorous, well-rooted two-year-old plants are set, they do not need cutting back the first year except to remove fruit buds shortly after planting. Pruning should be moderately heavy in the second year to stimulate strong new growth on selected canes. Do not permit plants younger than three years of age to bear more than a cluster or two of fruit, or the onset of the commercially productive period will be delayed. A large bearing area should be established in the shortest possible time.

Pruning Bearing Plants (over 3-4 years of age)

Make large “shaping cuts” — remove all low-spreading branches and the oldest canes if they are weak, particularly if in the center of the plant. “Head back” the upright “bull shoots” to the desired height to keep the bush from growing too tall. Essentially, you have then automatically selected the remaining, more upright canes to bear your crop next season and the following season.

On the remaining canes, systematically “thin out” the shorter, thinner shoots, leaving enough of the thick shoots to bear the crop and make new growth. Only experience can tell you how many shoots a particular variety of a particular age can carry and still perform well. It is probably better in most instances to prune too lightly than too heavily. Lighter pruning is usually practiced, as the plant grows older because it can carry more “wood” successfully due to a larger root system.

Renewal Pruning

When blueberries are about 8 to 10 years old, they are at their productive peak— but renewal growth has reached a minimum, and production will begin to decline from year to year. To prolong your plant’s productivity, renewal pruning is needed. Some provision must be made to revitalize the plant to prolong its productive period.

• Weak or badly diseased canes should be removed entirely. These canes can be identified by generally poor vigor and low fruit bud production. However, in eastern NC, many varieties do not sprout new canes readily from the crown. It may be necessary to either cut the cane back to a strong lateral which is properly located, or to cut the cane severely (“dehorn”) back to within 2 to 3 ft of the ground. By the latter method, it is hoped that new lateral branches can be forced from below the cut.
• Either method may result in a 1- to 3-year crop reduction, but the plants should then bear several more good crops. However, when rejuvenation becomes necessary, it is time to start considering newer and better varieties to which your acreage may be systematically replanted in the near future.

A good reference book, such as Pruning Made Easy, can answer questions and guide you through the pruning process.

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

Natural Control

• Serenade® Garden Disease Control for botrytis blight, powdery mildew, anthracnose and more.

When To Spray

Dormancy (late winter/early spring before leaves emerge)

• Monterey Horticultural Oil for thrips, mites, sawfly (eggs) and scales.

On Foliage

• Monterey Horticultural Oil for thrips, mites, sawfly (eggs) and scales.

At the First Sign of:

• Hi-Yield® Vegetable & Ornamental Insect Control for fruitfly (drosophila), leafrollers, thrips and more.

• Monterey Fruit Tree Spray Plus for aphids, mites, leafhoppers, spittlebugs, scale, thrips, fruit flies, powdery mildew, blight and more.

• Natural Guard® Caterpillar Killer Spray w/BT for omnivorus leafrollers.

• GardenTech® Sevin® Concentrate Bug Killer for aphids, mites, lygus bugs, spittlebugs, blueberry maggot, scales, sawfly, leafrollers, leafhoppers, Japanese beetles, mites, weevil and more.

Bud Swell (or when buds have loose scales)

• Hi-Yield® Captan 50W Fungicide for botrytis gray mold or berry rot and mummy berry.

Bud break (green tip--DO NOT apply after early bloom)

• Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for mummy berry and anthracnose.

When to Harvest

You can start harvesting your berries in the second season. The berry color should be blue or pink depending on the variety. Just because they are blue or pink does not mean they are ripe, they need about 7-10 days to develop fully. Put your picking container underneath a bunch of blueberries and gentle run your hand over the cluster and the ripe berries will fall off. During the ripening season check every day for ripe berries.

Storage

Blueberries will keep up to a week in your refrigerator. If not able to use right away put berries on a cookie sheet in a single layer and freeze until firm and then put them in freezer bags to enjoy all year long.

Annual average yield per plant:

• Self-pollinating, 1½ quart
• With another variety for additional pollination, 3-4 quarts