What You Need to Know to Start Growing Raspberries

Nothing is sweeter than popping fresh raspberries into your mouth straight from the bramble patch. The key to getting the biggest berries and the biggest yield from each plant is understanding what they need, and how they produce. Here's what you need to know to start growing raspberries.

Raspberries come in a multitude of varieties and colors. Varieties have been developed to grow in nearly all climates (zones 3 through 9). Depending on the variety you choose, you can harvest raspberries from early summer until mid fall-with mature plants producing 4 to 6 pounds of berries per season. Available colors include red, purple, black, and yellow. Because raspberries are self-pollinating, you can plant just one type of cultivar and still expect a bountiful harvest.

Plants can be purchased in pots or as bare-root plants. Because viral infections are the number one disease problem in raspberries, it's best to buy certified virus-free stock from a reputable supplier rather than acquiring plants from friends or neighbors. Ask local nurseries to recommend cultivars known to grow successfully in your area.

Then ask them which, if any, pests and diseases you need to be on the lookout for. The roots of bare-root plants should be soaked for two hours before planting. Cut the canes to 2 inches above the ground and space plants 2 to 3 feet apart, leaving 6 to 7 feet between rows.

Raspberries prefer full sun and acidic soil. They can tolerate both heavy and light soil, as long as it drains well and has an acidic pH of 6.5 or lower (ideally between 5.5 - 6.0). Fertilize them in the spring and dress them with compost after harvest. Avoid planting them in low spots where frost settles or water puddles.

Training makes cane management easier. Stakes or trellises should be set up before you plant to avoid injuring small plants. Most plants grow 5 to 6 feet high, so for each row, stretched wire between posts (every 3 feet off the ground) and tie the canes to the wires using soft ties. Individual plants can be supported by a single post.

Pruning raspberries depends on when they produce. Raspberries bear fruit in the summer (summer-bearing) or the fall (fall-bearing, also called ever-bearing).They are unique in that their crowns and roots are perennial, but their canes are biennial.

• Summer-Bearing Red Raspberries: In the fall after the last harvest, cut off all the fruit-bearing canes at ground level. In March or early April, thin by removing weak, diseased, and damaged canes at ground level. Leave only the strongest canes spaced about 6 inches apart.

• Fall-Bearing Red Raspberries (for one crop): Simply cut all of the canes down to the ground each spring. You'll only get one late crop of berries this way, but the crop will be larger and you won't have to try to determine which canes are two years old.

  Advertisement

  
  

• Fall-Bearing Red Raspberries (for two crops): Prune fall-bearing raspberries in the spring. For maximum yields, completely remove all the fruit-bearing canes from the previous midsummer. These can be hard to tell apart from the new canes (look for old, cracked wood and lateral side buds present farther down the cane). Leave enough new canes (canes with lateral buds present only at the tips) to produce a late, first summer crop.

• Yellow Raspberries: These come in both summer and fall bearing varieties. Prune them in the same way you would summer and fall bearing reds.

• Black or Purple raspberries: These raspberries need pruning three time a year. When the new canes reach about 3 feet tall, pinch 3 to 4 inches off the tips to encourage the development of lateral (side) shoots which results in more berries the following season. In midsummer, cut the fruit-producing canes off at ground level after harvesting. Finally, in late winter or early spring, remove the weak and unproductive canes (leaving the most vigorous), and trim back the side branches to 10 to 12 inches.

Diagnostic tool for troubleshooting berry crops. The Cornell University Department of Horticulture's website features an excellent diagnostic tool to help gardeners diagnose problems with berry crops. Use it to identify problems with raspberries, strawberries, blueberries, blackberries, and ribes. http://www.fruit.cornell.edu/berrytool/index.htm