Growing Blackberries

Blackberries, Black Raspberries, Red Raspberries and Yellow Raspberries are very closely related. Botanists separate the Raspberries from Blackberries by determining if the core stays in the ripe fruit or if the core is lost during picking.

Berries with the core intact are Blackberries and berries that lose the core and resemble a thimble are called Raspberries. A few berries are a cross between the two. Boysenberries and Olalieberries are a cross between Blackberries and Raspberries and are called Trailing Blackberries.

Because wild blackberries are so abundant, many gardeners pass up the opportunity to raise the domesticated kinds . . . which is a pity, since "tamed" blackberry plants offer so many advantages over their wild counterparts. Cultivated varieties not only produce heavier crops of fruit, but bear larger, juicier berries . . . berries that—in my judgment—retain more flavor after freezing than almost any other kind of fruit.

With the advent of thornless blackberry plants and dwarf varieties (such as Darrow) that require much less care than full-size varieties, there's no longer any excuse for not raising blackberries in your back yard.

There are two types of blackberries, erect and trailing. The primary difference is the growth habit of their canes. Erect blackberry types have stiff, arching canes that are somewhat self-supporting.

Trailing blackberries, also called dewberries in the East, have canes that are not self-supporting; they include the Marionberry, Boysenberry, Loganberry, Youngberry, and Thornless Evergreen.

Erect blackberries are more cold-hardy than trailing types. However, you can grow trailing types in colder areas if you leave the canes on the ground and mulch them in winter.

All bear fruit on two year old wood, except Everbearing Raspberries, which also fruit on first year growth. Everbearing raspberries are not truly everbearing; they bear a late Summer or Fall crop on the first year growth and a second crop the following Spring on two year old wood.

Cultivation requirements - Remember that after flowering and fruiting, any cane that bore fruit dies back to the crown. When establishing a new planting, it is very important to cut the top back on the bare-root transplants if this has not already been done at the Nursery. All the new growth that will arise from the transplant will come from primary buds just below the soil surface.

If you examine the crown of the plant, you will see 2-5 small buds or shoots just above the roots at the base of the crown. All the top growth above the primary buds is the cane that grew in the Nursery row the previous summer and is now two years old and programmed to flower and fruit.

If you leave this 2 year old top growth intact, it will start blooming and try to fruit at the expense of the new cane growth that you are trying to encourage from the primary buds.

Without a properly established root system, the newly transplanted berry may dry out in an attempt to ripen fruit on the excess cane. By cutting the tops back, your transplants will have a much better survival rate and better growth will result.

Any transplant will experience some stress. By cutting back your bare root canes, less stress will occur. It takes 4-6 weeks for new growth to show; leave 3-5 in. (7.5 to 12.5 cm) of the old top above the ground to "mark the plant" in the row..

Trailing blackberries - thrive in most soil types but good drainage is desirable. Soils that are naturally fertile, easily worked and retain moisture well, are the most suitable.

Black raspberries - prefer a loose textured, well-drained soil. Avoid sites with a high water table where water sits for long periods of time, especially during winter months. Black raspberries will thrive in most soil types and are cold hardy in most areas of Canada and the US.

Planting - Soak the roots of the bare root canes in water for an hour or so prior to planting. Plant the root system intact if possible, but if the planting hole is smaller than the root system, prune the roots to fit rather than "wad" them in the planting hole.

Avoid over-watering while the plant is dormant; over-watering can lead to root rot. Berries will die in mud! Normally, Spring soil moisture is adequate for growth if the root system was soaked prior to planting. Planting berries an inch deeper than they grew in the nursery row is mis-information; they should be planted at the same depth that they grew in the nursery row, covering any white sprouts arising from the crown.

Trailing blackberries - Two year old bare root transplants can be planted late Winter to early Spring. Avoid pruning the roots of thornless varieties as this may encourage thorny suckers. Plant 6-8 ft. (2 to 2.5 m) apart and train them on a trellis.

Black raspberries - Two year old bare root transplants can be planted late Winter to early Spring. The older stems or tops of the transplants can be cut back several inches. Space 3-4 ft.  (1 to 1.2 m) apart in the row and 6-8 ft. (2 to 2.5 m) between rows.

Pruning - When the canes reach a height of three or four feet, their tops should be clipped to encourage the appearance of "laterals", or side branches. Then—each fall, after harvest—the canes that bore fruit that year should be cut off at ground level and new canes (no more than ten per plant) allowed to develop.

When the new canes reach three feet in height, they—in turn—can be clipped to encourage the production of laterals. (And, after these shoots have borne fruit, they should be cut off at ground level, and so on.)

Trellising is beneficial for cane support. These summer-bearing berries produce fruit on second year canes (floricanes). In the fall fo the 2nd year, prune spent canes at ground level and thin others to approximately 4 canes per ft. (30 cm) of row. Cut off suckers which grow outside of rows. Trim remaining blackberry canes to 7 ft. (2 m).