Because canes of raspberry bushes are suceptible to damage from high winds, particularly when heavily loaded with fruit, all raspberry varieties benefit from some type of support system. That being said, red, black and thornless varieties of raspberries definitely benefit from a support. Supports can be an existing fence or a post and wire trellis system, which is very simple to build.
Wire Trellis-Hedgerow System for Growing Raspberry Plants
Raspberry trellises are simple and inexpensive to build. A trellis can help make the crop easier to manage and keep the canes off the ground so that berries are cleaner and easier to pick.
Step-By-Step Instructions:
- Sink two 8-foot pressure treated 4x4 posts about 3 feet deep in the ground with about 4 feet of the post above ground at anywhere from 10 to 20 feet apart. In sandy soil you'll need to add a quick-setting mortar mix to anchor the posts.
- Using nails, woodscrews or bolts, attach two 20- to 24-inch long pressure treated 2x4 crossarms to support wires at the top of each end-post.
- Attach a wire securely with u-nails or staples to each end of the cross arm at about 36 inches high for red raspberries and 40 inches high for the black and purple types. Wires can be wrapped one or two times around the post. Make wire as tight as possible.
After having constructed your raspberry trellis, plant the raspberry bushes between the wires and tie them loosely to the wire.
Spacing Raspberry Plants
Red Raspberries - The favored planting system for red raspberries is the narrow hedgerow. Set red or yellow raspberries every 2 to 3 feet, in rows at least 6 feet apart. Allow new primocanes to spread along the row but not wider than 12 inches. Wider rows invite fungal diseases because of slow drying conditions.
Black & Purple Raspberries - Set these out with 4 feet between plants and 8 feet between rows. Because these cultivars do not produce root suckers, they should be maintained in a hill system. The “hill” does not mean mounding the soil; it refers to the cluster of canes that develops from a single plant. Although black and purple raspberries do not send up new primocanes outside the hill, they can spread: the long, vigorous canes often arch down to the soil surface, where they may take root. It’s important to keep the canes controlled and trellised.
