Moxie Gardener

Anti-oxident-rich black raspberries can produce fruit for many years in your urban garden.

Studies have shown that dark colored berries contain very high levels of anti-oxidents, which are believed to help prevent cancer and heart disease. Black raspberries are particularly high in these anti-oxidents.

They’re sweeter and taste better than red raspberries, too.

Unfortunately, they’re more prone to all of the diseases that affect raspberries and other bramble-type fruit.

Don’t let that deter you from growing black raspberries in your urban garden. They are rarely, if ever, available for sale at supermarkets or even farmer’s markets. Growing your own is perhaps the only way you’ll get your hands on them.

Prepare the soil before planting in early spring. Add large amounts of well-rotted manure, compost and peat moss. Get your soil tested and add amendments to bring the pH down to a range between 5.6 to 6.2. Spread 25 lbs. of 10-10-10 garden fertilizer per 1,000 square feet of planting bed. Cultivate the soil well to break up any large clods of soil.

To guard against the spread of diseases from their more vigorous red cousins, plant black raspberries at least 300 feet away from red raspberries.

Plant black raspberry crowns four feet apart in rows 8 to 12 feet apart. (For urban gardens the smaller spacing is best; plant them 12 or more feet apart only if you will use a tractor to cultivate between the rows.)

Install a 4 foot high wooden stake next to each plant. Run a thick wire down the row, attaching it to each stake. The fruiting branches of each cane will be spread along the wire and secured with twine when they appear later in summer.

Mulch well between the rows and around individual plants. Spread and maintain a 3 to 4 inch layer of organic mulch such as wood chips, shredded bark, pine needles, or rotted leaf mulch. Hand pull weeds to reduce competition for water and nutrients and reduce the possibility of disease.

Provide your black raspberry patch with the equivalent of 1 to 2 inches of water per week. Never use an overhead sprinkler, it could help spread diseases; use a soaker hose instead.

Fertilize each year by applying 20 lbs. of 10-10-10 fertilizer (or an organic equivalent) per 1,000 square feet of planting bed. Split the application by applying half of this amount in mid-April and the second half in late May to early June.

Maintain the base of each row at a width of 12 to 18 inches and remove any suckers that grow outside this range. This helps bring light and air into the row, resulting in increased yields and healthier black raspberries.

Cut off the tips of new shoots in early summer when they reach a height of about 30 inches. These canes will send out lateral branches near the end of summer, which are fastened to the wire running the length of the row. These lateral branches will in turn send out small branches the following year on which the berries will form.

In early spring prune the lateral branches that formed at the end of the previous summer. Cut each off so that there are two buds per branch on thin diameter canes and up to six on stout lateral canes.

Also remove any main canes—those which are growing vertically out of the ground—that are less than 1/2 inch in diameter. Each healthy plant should have 2 to 5 canes that are over 1/2 inch in diameter. If all the canes are smaller than this, cut out all except the largest ones.

After the canes fruit in mid to late summer, they die. Remove them soon after harvest to control disease. Cut them off close to the ground. Also thin new shoots at this time and leave only 3 or 4 of the sturdiest ones per foot of row. These will form lateral branches that will bear fruit the following summer.

Remove all pruned materials and destroy them by burning or by putting in the trash. This will help stop the spread of the many diseases that raspberries are susceptible to. They also suffer from the same diseases that affect roses, to which they are related.

A raspberry planting that is properly maintained by mulching, watering, pruning and fertilizing will bear fruit for twenty years or more.

That’s a lot of anti-oxidents.

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