How to Grow and Harvest Blackberries in Your Garden

Few things are more rewarding as a gardener than harvesting fruit from your very own backyard! And the absolute best part is walking through your garden and plucking that fruit off the vine or branch and tasting that sweet (or tart), juicy flavor-packed goodness on a beautiful Summer day. Top this image off with a perennial plant that is extremely easy to grow and you have the blackberry.

Blackberries are perennial shrubs in the Rose family (Rosaceae). Blackberries themselves have many different forms, species, and varieties, but all of them belong to the Rubus genus. They can be grown almost anywhere and are often found growing wild in temperate regions of the world.

Blackberries are not only delicious, but they also have many uses and can be preserved easily! They are easy to grow, and have fairly low maintenance requirements. In this guide, we walk through everything you need to know about blackberries and their care. Let’s dig in!

Plant History

Blackberries are a part of the group called brambles, which are any plant a part of the genus Rubus. Raspberries are also considered a bramble.

For two thousand years, since the time of the ancient Greeks, blackberries have been collected and used for eating and for medicinal purposes. In Europe, they were gathered from hedgerows and used for medicinal and other purposes until the 16th century. The Evergreen blackberry (Rubus laciniatus) was domesticated in the 17th century in Europe.

The early European settlers of North America often viewed them as a nuisance at first because of their aggressive growth. You can imagine settlers trying to clear land and having to deal with a tangled, thorny mess.

It is likely that settlers did gather fruit from wild stands, but they were not cultivated widely in North America until sometime between 1850 and 1860. By 1948 in the U.S., they were produced on roughly 40,000 acres. Production was mainly in the southeast.

After domestication and regular cultivation, they began to be grouped into three main groups: erect, semi-erect, and trailing.

Description

Blackberries are considered perennial shrubs with alternate leaves of 3 to 5 leaflets. Leaves are bright green and toothed along the edges. Stems (or canes) are semi-woody and may or may not have thorns. The fruit is actually considered an aggregate fruit composed of many fused drupelets. Each drupelet is a tiny, fleshy fruit with a single seed inside.

Each aggregate fruit (or berry; although this term is not botanically correct) surrounds a fleshy white cone or core called a torus or receptacle. The receptacle separates from the plant when the berry is picked.

This is the main distinction between raspberries and blackberries, because for raspberries the receptacle remains on the plant when the fruit is picked.

Most Rubus species are biennial in nature. This means that they will grow vegetatively the first season, and then the second season they will flower, fruit, and die.

So, the first canes that are produced after planting are called primocanes—the “first” canes. During the Winter the leaves will die back, but the cane is still alive. In late Winter or early Spring, you will likely prune these primocanes, but we will talk more about this later.

As Spring turns into Summer, new leaves will grow on your primocanes and eventually little white flowers in clusters will begin to form. Your primocane is now in its second season, so it is now called a floricane.

You will notice new canes beginning to grow from either the crown of the plant or in areas close by. These are the new primocanes of your plant. New primocanes that spring up from the root system in random areas around your plant are also called suckers.

Once the floricanes produce fruit, they will then die because their life cycle is complete. Next year, the primocanes from this year will become floricanes, and the cycle will continue.

Cultivation

Erect and semi-erect blackberry types have their ancestry in the eastern North American wild blackberry species.

Erect varieties will grow 6 to 10 feet tall (if not tipped; more on that later). They sucker profusely from their roots rather than from their crown. Their cold hardiness is considered moderate to good, and today you can find both thorny and thornless cultivars.

Semi-erect varieties will grow 15 feet (if not tipped), but they produce canes from a crown rather than through many suckers. Their cold hardiness is considered moderate, and they have only thornless cultivars.

Arching branches may also root where they touch the ground and produce a new plant by a process known as tip layering.

Trailing varieties were bred from western species, unlike the erect and semi-erect types. Red raspberries are also in their lineage. Berries of the trailing type tend to have less noticeable seeds and the fruit is more conic in shape.

They also may ripen earlier with berries that are naturally higher in flavor, sugars, and acid. The canes will grow 10 to 20 feet and form from a crown. Their cold hardiness is considered poor to moderate, and there are both thorny and thornless cultivars available today.

A new type of blackberry has been developed from erect blackberry types called primocane-fruiting blackberries.

These will bear fruit in the Fall rather than the Summer, and they will bear on the canes that have grown during the first (or current) season, unlike other varieties which produce on canes that grew during the previous season. As a result, they can be cut completely to the ground in the Winter.

Propagation

Blackberries are propagated by root cuttings, tip layering, and suckers.

Root cuttings can be taken in the Fall. Dig up roots and choose those that are the size of a lead pencil or larger. Cut them into 3 to 6 inch lengths and store them at 32 degrees F in moist peat moss. Plant them in mid-Winter to early Spring.

Tip layering is the process of bending a cane down to the ground and piling soil on top of a section of the cane. After a few weeks, the cane should begin to sprout roots and you should be able to cut it from the rest of the cane so that it is its own plant. They will naturally tip layer as well if you don’t keep the canes upright on a trellis.

Tip layering is how my entire blackberry patch was started! I cut and dug canes from a family member’s patch that had arched over the trellis and naturally rooted into the soil. I did this in about mid-Spring and promptly planted them into my garden after digging.

Suckers may often pop up near your patch, and just like tip layering, you can dig up the little suckers and transplant them to your new site. Make sure that you water them well when you plant them. Suckers will often pop up in the Spring.

When to Plant

The optimal time to plant new starts is in the Spring. This will allow the plant’s root system to begin to establish and for the primocanes to begin to grow.

You will likely not see flowers or fruit in the first year unless the plant has an old cane leftover from the previous season. Even then, the harvest will be minimal, if at all.

You may also plant in the Fall, but be careful in USDA Hardiness Zones 5 or above. Your young plants may be damaged by freezing, so it is best to plant in the Spring if that is a concern. 

How to Grow

Once established, blackberries are extremely easy to grow. In fact, your problem may not be growing them but rather controlling them! Let’s look at the most important factors to keep in mind once you’ve decided to plant them in your garden!

Location

Plant your blackberries in a large, open space in full sun to part shade. Space is very important because even though your initial plants are small, they will turn into a thick mass of canes and foliage very quickly.

Because of their aggressive growth, they are not always good companion plants in the garden. However, there are a few different plants with growth patterns that compliment blackberries well, so stick with these companions if you’ve decided to interplant with blackberry shrubs.

Full sun is optimal so that the plants receive optimal sunlight for growth. Plants will be more productive in fthe ull sun. Part shade is tolerable if the plants are receiving afternoon shade in very hot areas.

An open site is also important for air flow. The more air circulation you have will reduce incidence of disease.

Spacing

Semi-erect and trailing varieties should be spaced 4 to 6 feet apart in the row to ensure adequate space. Erect varieties should be planted 3 to 4 feet apart.

If you have multiple rows, you will want to space the rows at least 8 to 10 feet apart. If that seems excessive, just wait until your blackberry patch takes off! You will thank yourself later.

They can also be planted in a hedgerow style, which basically means you are planting the plants closer together in a row so that the plants use each other for support.

However, you will likely have reduced harvests and it will be harder to harvest from. The upside to a hedgerow planting is that it can act as a living fence and is much less work for the casual gardener.

Soil

Well-drained soil is the best soil type for planting. They can tolerate wetter soils, however—more so than raspberries. Blackberries prefer a soil pH of 5.5 to 6.5. High amounts of organic matter are also preferred.

Soil organic matter content of 3 to 4% is ideal. You can add compost or well-rotted manure prior to planting to increase the organic matter content of your soil.

Do not plant in a site that has had problems with Phytophthora root rot, Verticillium wilt, or crown gall. Avoid planting in sites that were previously devoted to tomatoes, peppers, potatoes, melons, strawberries, or weeds such as pigweed, lambsquarters, or weeds in the nightshade family.

Moisture

Steady, sufficient moisture is extremely important for a berry crop. During the growing season, 2 inches of water per week is ideal. As the berries are ripening, 2 to 4 inches of water per week is optimal.

Using drip or trickle irrigation is a great way to make sure your berries receive ample moisture while also reducing the amount of water splashed on the foliage. Blackberries are much hardier than raspberries, however. If there was a time to worry about watering, it would be as the berries are beginning to grow and swell.

Climate & Temperature

Blackberries grow native on every continent except for Australia and Antarctica. They are cultivated primarily in USDA Hardiness Zones 4 through 8. Some varieties may be hardy up to Zone 3.

They require a certain amount of chilling hours between 25 and 40 degrees F in order to break dormancy in floricane buds, but temperatures down to 10 degrees F can injure buds of non-hardy cultivars. Temperatures below -15 degrees F can injure buds of the most cold-hardy cultivars.

Fertilizer

If the soil was properly prepared before planting, there is not much to worry about as far as fertilization is concerned. In fact, I have never fertilized my blackberries and they produce buckets of fat berries each season.

The one nutrient you may need to worry about is nitrogen. You can fertilize in the late Spring with a nitrogen-based fertilizer like calcium nitrate or ammonium sulfate. Organic sources of nitrogen are bloodmeal and alfalfa meal if you’re not wanting to use a commercial synthetic fertilizer.

You can apply ½ pound (0.25 kg) of actual nitrogen per 100 foot row per year to keep your blackberries growing vigorously. You may also choose to apply a ⅔ rate in the Spring before much growth starts and the last ⅓ about a month before expected harvest. Delay the second application for fall-bearing blackberries to late Summer.

Mulching

A commonly beneficial practice, mulching can help improve your yield. First, mulching helps conserve moisture and reduces loss of soil moisture due to evaporation.

Second, mulching will also reduce weed pressure around your new plantings.

Third, mulch will decay over time which will add organic matter to the soil. Make sure to reapply mulch every few years as it begins to decompose!

Trellising

Semi-erect and trailing blackberries will require trellising. There are many different types of trellises, but the main thing you are trying to accomplish with a trellis is preventing the plants from growing on the ground.

You can choose to create a trellis where you have to individually tie the canes or use a trellis that you can weave the canes through to keep them in place. Use sturdy posts that will be able to bear the weight and make sure they are in the ground far enough to prevent frost-heaving.

To learn more about the specifics on advanced trellising systems, North Carolina State Extension has a great article on trellis systems for caneberries like raspberries and blackberries. Another great resource is the 2007 publication called Fruit and Nut Production by Brenda Olcott-Reid and William Reid.

Pruning

Pruning is imperative in order to have optimal berry harvests and to prevent disease. The tricky part is that each type of blackberry needs to be pruned a little differently for optimal production.

The best time to prune is in late Winter to early Spring. This is considered dormant pruning, because the plants are dormant at this time. As an example, my farm is located in USDA Zone 6 in the midwestern United States, and I like to prune in late February to mid-March.

Another type of pruning is called tipping. Tipping is usually done in early Summer, and this stimulates lateral growth from the canes. Lateral growth is essentially side branches.

Erect Blackberries

Erect varieties should be dormant-pruned so that the canes are around 10 inches apart. Prune the laterals (side branches) so that they are only about 12 to 18 inches long during the dormant season as well. In early Summer, tip the plants so that the canes are only 3 to 4 feet tall.

Semi-Erect Blackberries

Semi-erect varieties should be tipped in early Summer to about 5 feet tall, with the lateral branches subsequently being tied up to the trellis in the later Summer months. When dormant pruning, you will want to retain the top 5 to 8 lateral branches and prune off any lateral branches underneath or in the bottom 3 feet of the main cane.

The laterals should be pruned to 12 to 18 inches in length. Tie the vertical parts of the canes when the canes are still green, and then you can tie the lateral branches horizontally on the trellis.

Trailing Blackberries

Trailing blackberry primocanes should not be tipped. The canes like to trail on the ground, so be sure to lift them and tie them onto a trellis accordingly. Canes can be lifted in late Summer or Fall, or they can be left on the ground during the Winter.

Those that are tied up in the Fall are said to have higher fruit yields, but if you live in a colder climate, be wary that you may encounter frost damage when Fall-training. Thin your canes down to 6 to 10 healthy canes. Remove any canes that appear weak.

Additionally, after the floricanes are done fruiting for all types except the primocane-bearing blackberries, and you have collected your berry harvest, it is a good practice to remove the dying floricanes as soon as possible. This will leave you with less pruning to do in the dormant season, and it will also open the canopy up for better air circulation.

When & How to Harvest

Finally, the day is here for you to pick your delicious blackberries! You’ll know that they are ripe when they are fully mature in color and pluck off fairly easily.

As a note, raspberries detach easily when ripe as the receptacle inside stays behind when you pick them off. During harvest, the receptacle comes off with the rest of the berry, so there is less “give” compared to raspberry harvesting.

Another way to tell if your berries are ripe is by taste. Unripe berries will taste sour or flavorless. Taste-test each day until you find your optimal harvest time. Some varieties are naturally tart, so don’t be dismayed if you can’t seem to find the optimal harvest time. Drizzle a little sugar on them and you’ll be good to go.

My favorite time to pick is when the berries are fully colored (bluish-black; no red) and the berry feels soft instead of firm. Storage time is shorter when the berry is softer but I usually eat or store them right away!

Popular Varieties

• ‘Navaho’ – An erect variety suitable for growing in the northeast, southeast, midwest, and northwest. ‘Navaho’ is thornless, has small to medium fruit, and sweet flavor. This variety is also resistant to anthracnose and root rot.
• ‘Kiowa’ – An erect variety that is a mid-season producer suitable for the southeast and midwest U.S. This thorny variety has large flavorful fruit and a long ripening season.
• ‘Prime-Ark 45’ – This late season variety is an erect variety that is fall-bearing/primocane-bearing. The berries are firm and medium-sized. In some areas, this variety may ripen too late to have a decent crop.
• ‘Chester Thornless’ – This semi-erect thornless, late-ripening variety has large, deep black, tart berries. It also has better cold hardiness and yield than the similar variety named ‘Hull Thornless’.
• ‘Hull Thornless’ – This mid-season-bearing thornless variety is one of the sweeter and less tart of the semi-erect type.
• ‘Triple Crown’ – This semi-erect variety is thornless and bears late. However, it is known as a very vigorous plant, producing large berries with a very sweet flavor.
• ‘Marion’ – This thorny trailing variety has been a staple in the Northwest for many, many years! In fact, this variety is typically sold as “marionberry”. The fruit is medium-sized, aromatic, and extremely flavorful. Fruit can be soft and irregular.
• ‘Columbia Star’ – This trailing variety ripens early to mid season and is thornless. The plants are vigorous with big, uniform berries with excellent flavor.
• ‘Logan’ – A trailing thorny or thornless variety, ‘Logan’ ripens early and produces raspberry-red medium to large berries.

Fungal Diseases

While blackberries are fairly immune to most diseases, there are still a few you’ll need to look out for. Let’s look at the most common fungal problems you’ll likely come across as you grow them in your garden.

Gray Mold (Botrytis Fruit Rot)

This is usually a problem (caused by the pathogen Botrytis) that occurs after berry harvest when the berries are in the refrigerator. You will notice a whitish-gray growth on the berries.

If the infected berries are left on the plant, they may become so overgrown with gray fungal growth that they appear mummified. The best way to reduce chances of infection is by promoting air circulation by trellising, training, and pruning to proper spacing between canes.

Anthracnose

Infected leaves and canes will develop purplish spots that enlarge. Gray centers of the spots on leaves may drop out, and the spots on the canes may become sunken over time. Stunting and girdling of the canes will cause many canes to eventually die.

Choose anthracnose-resistant varieties and/or apply lime-sulfur or copper fungicides one time in the Spring when the new leaves are just bursting forth. Make sure to prune out and burn any infected canes.

Orange Rust

This disease is easily identified in the Spring. Young shoots will develop weak and spindly, and the leaves will be small, pale green to yellowish in color. In a few weeks, blisters will form on the leaves and then rupture to produce masses of powdery, rust-colored fungus spores that spread by wind.

The leaves will wither and drop in late Spring. New leaves at the tips will appear normal, but the canes will remain infected and will not produce blossoms later.  Eliminate sources of infection immediately by completely destroying plants before fungal spores are discharged. Make sure to purchase healthy plants from a reputable nursery for new plantings.

Insect Pests

Blackberries are unfortunately not immune to pests. There are several insect pests that can cause some significant damage to your plants. Let’s take a look at those that are most common, as well as how to control them.

Japanese Beetles

These beetles usually appear mid-season. They have shiny metallic greenish-brown bodies. They feed on leaves and can virtually skeletonize bramble leaves in a very short period of time.

Damage may not affect established plantings as much as it does plants that are between one and three years of age. Commercial traps can be purchased, but these are known to attract Japanese beetles, so make sure if you are using these traps you put them far away from your plants.

Another option, besides insecticides, is to handpick beetles every one to two days and throw them into a bucket of soapy water. The soap prevents the beetles from crawling up the side of the bucket, and thus the beetles subsequently drown in the water. This can be very effective if you are able to stay on top of it.

Planting companion plants of garlic, tansy, or rue may also be effective in deterring Japanese beetles. Beetles are attracted to damaged plants, so prevent damage early if possible.

Spotted Winged Drosophila

Adult flies look very similar to a fruit fly, but males have a large black spot on their wings that makes them unique. The larvae look like tiny white worms and can be found within the fruit.

More than likely if you’ve picked blackberries right off the plant and eaten them, you’ve likely eaten a few of these tiny larvae. Soaking the fruit in a warm saltwater solution will cause the larvae to float.

Adult flies will lay their eggs in the developing fruit and subsequently create a tiny scar that may eventually cause fruit collapse and rot.

Besides insecticides (which should only be applied if you KNOW the larvae are present and you know it will be a problem for you), another option is to refrigerate the berries immediately to ensure the larvae do not develop any further. Do not leave overripe fruit on the plant or berries on the ground. Clean up any debris in the area.

Blackberry Psyllid

Similar to aphids, psyllid are small winged insects with reddish-brown stripes on the wings. When disturbed, they will jump. Adults will feed on the leaves and leave a white, milky substance.

Severe damage will result in curling of the leaves. Psyllid damage will often not affect yield that much, so insecticide treatment is not recommended. The best prevention is to NOT plant them near a stand of conifers as they like to overwinter in pine trees.

Cane Borers

Red-necked, flat-headed, and bronze cane borers all can be pests that do damage to brambles by burrowing into the canes. This develops swellings at the bore sites on canes usually within 1 foot of the ground.

In some instances, boring sites can be seen as high as 4 feet off the ground. Infested canes will die or be severely weakened. If you see any infected canes, prune them out immediately and burn them. Insecticides can be applied before bloom.

Yellowjacket Wasps

While not necessarily a threat to the berries, they may be a threat to those harvesting the berries. Yellowjackets are attracted to fully ripe and injured fruit, and therefore may pose a danger to the unsuspecting fruit picker.

Keep ripening berries off the ground by having adequate trellising and support and regularly pick ripe fruit. You may also put traps around the perimeter of the patch before berry ripening.

Picnic and Sap Beetles

These beetles will bore into fully ripe and overripe fruit to lay their eggs, therefore causing damage to the fruit and potential disease infection of fruit-rotting fungi. They can also become a contaminant in harvested fruits.

Pick damaged or overripe fruit and place it in a plastic bag away from the area to attract and trap beetles that may be looking for a sweet treat. Once beetles are trapped, tie the bag and destroy it to eliminate some of the beetles.

Preservation

Refrigerate berries immediately for optimum shelf life. If you are picking on a hot day and you have a large harvest, bring berries inside in shifts as you pick.

Do not wash the fruit until you are ready to use the them. Handle the berries gently when you do wash them. Blot any wet berries with a paper towel before refrigerating after washing.

Because they do not have a long shelf life, it is a great idea to freeze them if you know you won’t be using them right away. You may also can blackberries into delicious jams, jellies, and preserves.

Plant Uses

Blackberries make an excellent sweet treat during a hot Summer day. My favorite thing to do is snack on them as I cut flowers in my cutting garden during the evening.

You can eat blackberries fresh or drizzled with some sugar. Many pies and cobblers have been made using fresh fruits in the Summer. They can also be canned into jams, jellies, and preserves.

Another option is to make them into wine or brandy! They are also used to flavor liqueurs and cordials. Blackberries are high in antioxidants, potassium, phosphorus, iron, and vitamins A, C, and E.

Their leaves and canes with unripe berries also make excellent filler and greenery in cut flower arrangements! In fact, because I’m a cut flower farmer, suckers are a staple in my early Spring arrangements.

Frequently Asked Questions