How Many Raspberry Plants Do I Need? A Complete Guide

Raspberries belong to a large group of fruits known as brambles, all in the plant genus Rubus. Raspberries can be grown successfully in most areas of Minnesota.

Three main types that can be grown in the home garden are red, black and purple. Yellow raspberries are red raspberries that dont make red pigment.

Raspberry plants have perennial roots and crowns, but their canes (branches) live for only two summers. Most raspberry plants bear fruit in summer.

How different raspberry varieties grow

Red and yellow raspberries produce many new canes from the base of the floricanes and from buds produced on the roots that become underground stems or stolons. The plants can spread in any direction. Thus “raspberry patch” is an apt name if the canes are not controlled through pruning.

Black and most purple raspberries produce primocanes only from the buds at the base of the floricanes. These clumps or “hills” stay where you originally plant them.

Everbearing red raspberries, also called “fall-bearing” or “primocane-fruiting” raspberries, are able to grow flowers during the first year. These varieties produce fruit at the tips of the primocanes. During the second year, they can produce a summer crop on the lower part of the same canes.

One problem with this type of raspberry in Minnesota is that in areas with a short growing season, many berries may be lost to early autumn freezes. Pruning of fall-bearers may be adjusted to allow for both a fall and following summer crop, or to take just the fall crop.

The University of Minnesota Agricultural Experiment Station has been testing varieties for many years to find those best suited to our climate. This list is based on that research. Most of the varieties on the list are hardy throughout Minnesota; those with hardiness described as “fair” or “poor” will perform best in protected sites and in the southern part of the state.

There are many more varieties available, with more being released every year, that may be hardy to some areas in Minnesota. If winter injury is a concern in your garden, primocane-fruiting varieties may be the best choice.

Variety	Fruiting type	Hardiness (zone 4 to zone 3)	Description
Autumn Bliss	Primocane	Good to fair	Large clusters of bright red, mildly sweet berries. Early ripening. Very good for freezing.
Autumn Britten	Primocane	Very good to good	Very large, firm, flavorful berries. Early ripening. Very good for freezing.
Boyne	Floricane	Very good to good	Very hardy. Produces deer red, medium size, tender, sweet berries. Very good for freezing.
Caroline	Primocane	Good to fair	Very large, rich, sweet berries. Good for freezing.
Encore	Floricane	Very good to fair	Sturdy, vigorous, nearly thornless upright plants produce a late season crop of large, sweet, firm berries.
Festival	Floricane	Very good to good	Nearly thornless, productive plants. Less vigorous. Medium bright red berries.
Heritage	Primocane	Very good to good	Large, bright red, super-sweet berries on vigorous, upright canes.
Killarney	Floricane	Very good to good	So productive it will weigh down the upright canes. Firm, sweet fruit. Disease resistant.
Latham (1920-UMN variety)	Floricane	Very good to good	Vigorous plants produce lots of large, sweet, firm, bright red berries. Very good for freezing. Disease resistant.
Nova	Floricane	Very good to good	Very hardy plant with fewer thorns. Medium size, firm, bright red berries with a good, slightly tart flavor. Very good for freezing.
Polana	Primocane	Good	Large, firm berries with good flavor. Early ripening.

Variety	Color	Fruiting type	Hardiness (zone 4 to zone 3)	Description
Anne	Yellow	Primocane	Good to fair	Widely adapted plants produce pale, yellow, very sweet, mild berries. Heat tolerant.
Black Hawk	Black	Floricane	Fair to poor	Vigorous plants produce lots of rich, sweet, firm black raspberries. Disease resistant and heat tolerant.
Bristol	Black	Floricane	Fair to poor	Vigorous, upright canes produce large clusters of firm black raspberries. Excellent flavor.
Fallgold	Yellow	Primocane	Very good to good	Produces large, golden, firm, sweet berries. Very hardy.
Honeyqueen	Yellow	Floricane	Good to fair	Honey-sweet, peach colored soft berries are produced on arched, spiny canes.
Royalty	Purple	Floricane	Fair to poor	Vigorous plants are heavy producers. Pick red for bright raspberry flavor, or purple for sweet, rich flavor.

Early spring is the best time to plant raspberries. Choose a planting site that is in full sun. The plants will grow in part shade, but will not produce as much fruit.

Raspberries prefer rich, well-drained soil. A few inches of compost mixed into the soil prior to planting will create a high-quality planting site. A good rate is about 3 1/2 cubic feet of compost per 100 square feet.

Till the soil well before planting.

This video describes how to plant a row of raspberries and build a simple wire trellis.

• Grow raspberries in a part of the garden that has good air circulation, good drainage and full sunlight.
• Good air movement helps leaves dry faster, which reduces disease problems. Standing water will increase the likelihood of disease problems and death of the plants due to a lack of oxygen to the roots.
• Any well-drained soil is good for growing raspberries. Irrigation will be needed on a sandy soil, and even on more moisture-retentive soils during dry spells.
• Raspberry canes are sensitive to drying out, so avoid planting in a very windy spot.
• Raspberries begin to bloom in late May or early June. Bumblebees, honeybees, and other wild bees are excellent pollinators of brambles. The more bees working your planting, the more fruit you will harvest.

Planting raspberries in a row along a fence or wall makes them easy to manage and, best of all, easy to pick. Or you can grow your raspberries in more of a rounded patch. Either way, space red or yellow raspberry plants every 2 to 3 feet.

Whether youre planting bare-root or potted plants, the key is to keep the crown of the plant 1 or 2 inches above the ground.

• When you place the plant in the hole spread out the roots.
• Try not to wrap the roots around in the hole.
• If any roots are particularly long or unruly, they can be trimmed off.
• If planting a potted plant, make sure to loosen the root ball and cut any tightly wound roots. This will help the roots spread better once planted in the ground.

Allow new primocanes of red and yellow raspberries to spread along the row or in between plants but not wider than 12 inches. Wider than that and the plants will be difficult to manage and harvest, and more prone to fungal diseases because of slow drying conditions.

Because these types do not produce root suckers, they will create what is commonly called a hill. The “hill” is not made by mounding the soil; it refers to the cluster of canes that develops from a single plant.

Although black and purple raspberries do not send up new primocanes outside the hill, they can spread. The long, vigorous canes often arch down to the soil surface, where they may take root. Its important to keep the canes controlled and supported to prevent this.

Try growing raspberries in a narrow raised bed with a decorative fence for support. It will keep them contained to a small area and make pruning easier.

Raspberries need lots of water from spring until after harvest. Because the root system is in the top two feet of soil, watering regularly is better than an occasional deep soaking.

Raspberries need 1 to 1.5 inches of water per week from flowering until harvest. Use a rain gauge or check reported rainfall, and irrigate accordingly.

All types of raspberries require support to prevent the canes from wind damage, bending over, cracking, and getting out of control.

A trellis can be as simple as a couple of posts and twine for a row of plants, or a decorative obelisk, teepee or arbor for individual or mass plantings.

Supporting the plants will not only keep them healthier and more productive, but it will also keep them looking nice.

Plant sturdy ornamentals like yarrow, echinacea or rudbeckia, or perhaps herbs or other edibles like kale alongside your raspberries to create a beautiful mixed garden. These will help support the raspberries and invite beneficial insects into the garden.

No matter what kind of trellis you design for your raspberries, the goal is simple: Keep the canes and fruit off the ground and leave enough walking space on each side for harvest. Raspberries trellised with metal and wire on a small farm. The metal trellis used in this home garden is similar to the larger scale construction. Use a rototiller or hand tools to till the soil 8-12 inches deep before planting.

A raspberry trellis should include sturdy support posts and several levels of wire or twine strung between the posts on either side of the plants.

If you use wire you will need a couple of other supplies: Earth anchors behind the end posts, and gripples or strainers. Both serve to secure the wire and keep it tight.

The advantage of using wire is that it will not loosen or wear out over time in the way that twine does. Twine takes less time and supplies to install, but it does not work as well as wire.

• Measure out and till the soil in a 2-foot strip where you will plant the berries.
• The tilled space should be 2 feet longer than the intended row length so that the plants on the ends will not be growing against compacted soil and turf.
• This step is especially important if the area was previously in turf, as the soil will be too compacted for gardening.

• Plant them 18 to 24 inches apart in moist soil.
• Water thoroughly after planting.
• Apply woodchip or straw mulch to help keep moisture in and weeds out.

• Pound in two sturdy metal or wooden posts at the ends of the rows.
  • If using metal posts, they should have holes down the length of them, for stringing the wire.
• The posts should be 5-6 feet long so that 1-2 feet are below ground and 4-5 feet are above ground.
• Twist the earth anchors in, one on each end of the row, 2-3 feet behind the end posts. They should be all the way into the ground so that just the top loop is exposed.
• You can use a metal pole or shovel handle to twist it in.

• Using 12.5 gauge high tensile wire (or similar), roll it out along the row.
• Cut it at a length that is 2-3 feet longer than the length of the row.
• Cut two more pieces that are a little over 2 times the length of the space between the earth anchor length and the top of the post (you will be making a loop with this wire, to connect the anchor to the post).
• Use safety glasses and leather work gloves. The wire is high tension and may spring back when cut.

• Starting on one end, loop one of the shorter wire pieces between the earth anchor and one of the end posts.
• The wire should loop through a hole near the top of the metal end post.
• Use a gripple and gripple tool to connect and tighten the loop (find gripples and instructions online).

• String the long pieces of wire along the length of the row, and into holes in the end posts at either end.
• Using gripples make small loops around the post with the wire.
• Use the gripple tool to tighten the wires so that when you shake them, they move very little.

The final levels should be approximately 2, 3, and 4 feet above the ground.

Managing pests and diseases

Keeping plants healthy and well-cared-for is the best strategy for preventing a host of issues. When issues do arise, it is important to look closely at what you are seeing. Where is the damage located: leaves or fruit, primocanes or floricanes? Correct diagnosis is key in taking the right steps to address problems as they arise.

Find help identifying common pest problems:

• Spotted wing drosophila are invasive fruit flies capable of laying eggs in ripening and ripe fruit, leading to mushy berries.
• Sap beetles are small beetles that are attracted to the smell of overripe fruit.
• Multicolored Asian lady beetle
  • This invasive lady beetle species can be found feeding on the fruit in the fall, especially if the garden is located near a soybean field.
  • They are attracted to sweet fruit.
  • Beetles can have few or many spots, the identifying feature is a black “M” shape on the white band between their head and body.
  • The best management strategy is picking fruit regularly.
• Corn rootworm
  • These slender beetles are a quarter inch in length and range in color from yellow to tan to green.
  • Beetles burrow into underripe and fully ripe fruit, destroying the berries.
  • Beetles can often be found feeding in groups in late summer, and can do a lot of damage.
  • Insecticides can be a helpful tool. Make sure to read the label carefully, especially to check for the amount of time needed between application and harvest.
• Yellowjackets
  • Wasps are brightly colored, with yellow and black stripes.
  • Wasps are attracted to overripe fruit, especially in the fall, so frequent picking will make the patch less attractive to them.

• Gleaming bronze and bright green Japanese beetles can be seen mid-summer feeding and congregating on foliage.
• Flat-headed cane borers (red-necked cane borer, bronze cane borer)
  • Occasionally cause scarring on raspberry canes, tip dieback, and cane death.
  • Adults are small, metallic, and slender, larvae feed inside canes and are pale and maggot-like in appearance.
  • Adults cause damage on the exterior of canes, leaving scars behind as they lay eggs, and can feed on leaves.
  • Larvae feeding inside the cane cause a majority of the damage, causing tip dieback, galls, and dead canes.
  • Observe plants for tip dieback, galls, and scarring, and if it is observed, prune to remove larvae.
• Spider mites can become an issue in hot weather, causing the underside of leaves to take on a bronze color.
• Misshapen, crumbling fruit can be caused by tarnished plant bug feeding.
• Potato leafhopper
  • Leafhoppers feed on younger leaves, causing curling, yellowing, and stunting.
  • These mobile, jumping insects can become an issue during periods of hot, dry weather.
  • Adults are elongated, small (1/8 inch), and wedge-shaped.
  • Natural enemies can help keep populations in check.

Rabbits are partial to raspberry canes in winter and will eat them, thorns and all, right down to the ground or the snow line. This is particularly damaging for summer-bearing raspberries, while fall-bearing raspberries are typically mowed down every spring anyway.

A simple chicken wire fence around your raspberry plants should protect them from rabbits throughout the winter. A cane blight lesion on a raspberry primocane

To properly diagnose pest problems on raspberry plants, it is important to understand the normal growth pattern of these plants.

When trying to identify what is killing leaves or canes, always check to see if the symptoms are on the primocanes or floricanes. Since floricanes die in the middle of summer, yellow and dying leaves on floricanes after June is considered normal, but yellow leaves on primocanes may indicate a problem.

Diseases can be limited by planting certified disease-free plants, destroying wild or abandoned brambles near the garden, and removing weak and diseased plants in established plantings.

After harvest, remove and destroy canes that have fruited or are weak.

One of the most effective measures is to improve air circulation by proper thinning and pruning and by controlling weeds.

Keep an eye out for spots, discoloration, parts of the plants dying, or moldy growth on leaves or fruit.

Cane blight is a common reason for the dieback of canes on raspberries. Disease lesions near the base of the cane cutoff water and nutrient transport to the rest of the cane, causing it to die.

Gray mold is the most common fruit rot disease of raspberries in Minnesota.

• The disease likes cool and wet weather during flowering and harvest.
• Gray mold causes raspberry fruit to rot and become moldy while still on the plants.
• In ripe fruit, gray mold may not appear until after picking and spreads quickly in a container.
• Choose planting sites with full sun, good soil drainage and air circulation.
• To manage this disease, plant in narrow rows, remove weeds often and thin plantings that have become overgrown.
• In strawberry patches with a history of gray mold, remove and discard all straw in early spring. Replace with fresh straw or other organic mulch.
• Fungicides can be used to manage gray mold fruit rot.

In raspberries, phytophthora crown and root rot causes canes to die back, due to an infection at the crown, or base, of the canes. The crown is located at or just beneath the soil surface.

Phytophthora infection causes brown discoloration on the outside and inside of the crown. It thrives in wet soils.

Positive confirmation of phytophthora infection is necessary before diagnosing and treating it. Dig up and submit an infected crown to the Plant Disease Clinic for diagnosis.

Prevent this disease with good site selection and cultural practices:

• Plant on well-drained soils, avoiding heavy, water-logged soils.
• If planting on heavier soils, create raised rows or raised bed gardens before planting, to increase water drainage.
• Do not overwater your raspberry patch.
• If you remove an infected raspberry patch, wait several years before planting raspberries there again. Choose a better area for your next planting if possible.

Hot days with strong sunlight may cause sunscald on berries forming white or colorless drupelets (the small, individual, seed-containing parts of each berry). The white drupelets will be flavorless, but there is no harm in eating them.

Once the weather cools, plants will produce normal berries. Heat can also cause berries to ripen faster than you can pick them, which can attract insects. Pick ripe fruit immediately.

Very few raspberry varieties are completely hardy in Minnesota. Even hardy varieties can exhibit symptoms of winter injury following severe winters. Winter injury can also occur after winters when the temperature fluctuates between mild and extremely cold.

Winter injury is often confused with cane blight, but it has symptoms that are different from other diseases.

• The tips of the canes are most susceptible to winter cold.
• Mild winter injury will result in the death of the top few inches of a cane.
• With severe winter injury, the top few feet of the canes will die.
• In almost all cases of winter injury, there will be healthy leaves at the bottom of the cane.
• If the winter injury occurred with a few inches of snow, then the canes die to snow level and will produce healthy leaves and fruit from the lower canes.

Raspberries that produce flowers and fruit on first year canes (primocanes) will always show some dieback in the spring. Dieback in fall-bearing raspberries is normal and is not considered winter injury.

Flowering in primocanes always starts at the tips of the canes and later flowers sprout lower in the cane. Any part of the cane that produces flowers will die in the winter. Always choose varieties that are suitable for your zone in Minnesota.

Leaf spot, spur blight, cane blight and anthracnose can make raspberries more susceptible to winter injury. Healthy plants will survive the Minnesota winters better.

Raspberry Planting Guide | Soil, Sun, pH, Fertilizing, Growing & Caring

FAQ

How many raspberry plants should I grow?

If you want 20 lbs of fresh raspberries per season, plant 4-10 raspberry plants. If you plan to freeze or make jam, aim for 15-25 plants per person.

How long does it take a raspberry plant to bear fruit?

Raspberries will start producing fruit a year after planting. Rabbits love to eat the canes in winter. A chicken wire fence will help prevent rabbit damage.