Two varieties of red raspberries (Rubus idaeus) grow in U.S. Department of Agriculture plant hardiness zones 4 through 8. Summer-bearing cultivars produce one crop in the early summer; ever-bearing varieties produce crops in the spring and fall. To grow taller plants that yield more berries, the canes, or vines, need to be supported on a wire trellis. To build a raspberry trellis, you need sturdy posts that are atleast 3 inches wide and 8 feet long, vary dimensions based on the size of your raspberry planting and available materials.
If you want to grow summer-fruiting raspberries in a small garden, train the canes to grow on a single fence. Bury posts 30 inches deep and 15 feet apart. Stretch 12-gauge wires between the posts at 2-foot, vertical intervals. Tie the spreading raspberry canes to the wires. If you want to be able to remove the trellis posts and return them at a later date without having to dig the holes again, sink 30-inch-lengths of PVC pipe into the ground, one for each post. The posts fit inside the PVC pipes, which should be barely wider than the posts.
Fence with Parallel Wires
To grow raspberries that bear fruit in the fall or to increase the yield for summer fruiting raspberries in a small space, construct a single fence with parallel wires. Plant posts into the ground at 15-foot-intervals. Put a 3-foot-wide cross member on top of the posts. Add a second cross member 2 feet below that. Make the cross members out of 2-by-4s or similar size timber. Fasten screw-eyes on the ends of the cross members and run 12-gauge wire through the screw eyes. Fasten thinner wire or garden twine every 2 feet between the wires. Train the canes to grow on both wires.
For a very small garden drive your 8-foot-tall post 30 inches into ground and plant one to three plants at the base. As the canes grow longer tie them to the post with garden twine. You could optionally put a 3-foot-long cross member made from a 2-by-4 on top of the post to provide slightly more room for the canes to spread.
Growing in a Container
If you want to grow raspberries in a container, drive a small pole into the container and tie the growing vines to it. Bamboo poles make good stakes because they are both strong and attractive. Ensure the container is deep enough to properly secure the stakes and heavy enough to support the top-heavy plant as it grows and is staked.
- Royal Horticultural Society: Raspberry
- University of Illinois Extension: Planting Raspberries
- Washington State University Extension: Growing Raspberries
- North Carolina State University Extension: Raspberries in the Home Garden
- Purdue University Extension: Raspberries
- Kansas State University Extension: Raspberries and Blackberries
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