If you are looking for something easy to grow and have a little space, blackberries are for you. Sweet tasting blackberries, grow wild in the woods and along trails in many parts of the country. They successfully compete with a wide variety of weeds in the wild. When you plant a few in your yard or garden, they will easily thrive. With a little care and attention, you will you will be rewarded with a big and juicy crop.
Blackberries are self-fertile and so will produce fruit even if only one plant is grown.
The best berries will be produced when they are in full sun. However, where space is at a premium, a blackberry cane will produce good crops even when grown in deep shade none of the other common fruits will survive in these conditions.
Blackberries produce their flowers very late in the season so frost will never be a problem. Low lying land or frost pockets are quite suitable for blackberries.
Blackberries will grow reasonably well in almost all soils. Blackberries will produce of their best in medium, well-drained soil which contains plenty of organic matter. They like the soil to hold a good supply of water, especially when the fruits are developing in summer. The worst soil for a blackberry is light chalky soil – lots of well rotted compost will help to improve these conditions.
Plant erect varieties 2 to 4 feet apart, and trailing varieties 5 to 6 feet apart. Prune heavily at planting to encourage new plan the growth. The roots are very sensitive to sunlight, so plant on a cloudy day.
When planting the canes, keep the crown of the roots level with the soil surface. This normally means digging a broad hole about 12cm (5in) deep. Spread the roots out into the hole and cover them in crumbly soil, firming it down with your hand. When planted, water well to provide moisture in the initial stages of growth. Cut the plants back to a good bud about 30cm (12in) high.
Immediately after planting (before if you want), trim the canes to a length of 25cm (10in). It’s tempting to leave the canes longer, hoping they will produce fruit next year, but this does not pay off in the long run.
The berries are produced on the previous year’s growth, and for this reason, no blackberries will be produced during the first year. Most varieties can be harvested from early August up until early October if the weather is good.
There are two methods to determine if blackberries are ready for harvest.
First look at the color, the berries should be deep purple or burgundy (almost but not quite black) and look plump.
The second method is to pick a test blackberry. Grasp a berry between your thumb and finger then gently twist. If the fruit comes off easily leaving the stalk behind then it’s ripe. Eat the blackberry to taste it! Some trial and error is required but if you start the harvest process from late July onwards you will soon be able to judge the correct time for harvest.
It’s best to pick the fruit little but often to encourage the formation of more fruit.
Frequent picking will also reduce the risk of the fruit over-ripening and rotting which will only encourage disease. The best time to pick blackberries is when the weather is dry, wet blackberries do not keep longer than a day before they begin to rot. As soon as the berries are harvested place them out of direct sunlight in a cool area.
Blackberries do not ripen when picked and they should be eaten within a day or so of harvest. If you want to keep them longer then place them in the refrigerator and they will be good for three or four days. Keep them slightly moist in the refrigerator for the best results.
It is an easy job to propagate a blackberry. The best time is around mid-September. Select a stem which is in perfect condition (growing vigorously with no blemishes) and bend its tip to the ground. Where it touches the ground, dig a small hole about 15cm (6in) deep and bury the tip of the stem into the hole. Cover with crumbly soil to the surrounding soil level. If the stem looks like springing out of the hole, place a few largish stones over the soil to keep it in place (remove them two months later). Water well if the conditions are dry.
The stem tips will root in a couple of month’s time, and can be dug up and moved to their final position early Spring next year. To do this, cut the parent stem about 30cm (12in) from the new plant. Dig up the new plant, trying to avoid any root disturbance and plant in their new positions.
General Pruning Care
Blackberries have only three main needs that make support and training important – light, circulating air and removal of last year’s fruiting stems.
As soon as the blackberries have been picked, cut the stems which have produced berries this year to ground level. Don’t prune any stems which have not produced fruit this year, they will be the ones which produce blackberries next year. With thorny, strong growing varieties a good pair of gardening gloves (strong trousers and shirt as well, if you have them!) are essential. If you have the time, during mid-April have a good look at the new stems and cut back maybe 25% of those which are growing very vigorously.
Supporting blackberries is not essential with the stronger growing varieties, although all blackberries like a bit of support. The idea behind supporting them is to permit a free circulation of air within the plant, thus helping prevent disease in general.
The best way to do this is to put wooden posts into the ground every 2m (6ft) and run wires between them at 70cm (2ft) heights up to 2m (6ft) high. As the new stems grow, tie some of them into the wires. The result will be that some stems will be unsupported and form a natural arch over the ground, whereas others will be tied to the supports and grow slightly higher. This will result in less congestion at the center, promoting greater circulation of air and exposing much of the plant to the sun.
If you have the time to support all the stems, so much the better.
(A) Train trailing plants to a two-wire trellis.
(B) Train erect blackberry plants to a one-wire trellis.