How to Grow Dewberries

Install a three-wire trellis in a well-drained garden bed that receives full sun. A three-wire trellis has 6-foot-tall support posts with a wire running between them at the top, another running 4 feet off the ground and a third running 2 feet from the ground.

Plant the dewberries at the base of the trellis. Space plants four feet apart in each row and space rows eight feet apart. Each row requires its own trellis.

Water the dewberries immediately after planting them, moistening the top 8 inches of soil. Continue to irrigate the plants deeply one to two times a week in spring, summer and fall. Provide 1 to 2 inches of water at each irrigation.

Mulch the soil around the base of the plants and between the dewberry rows to prevent weed growth and to keep moisture in the soil. Use a 3-inch layer of straw or organic mulch, and replenish the mulch each year to maintain its depth.

Fertilize the dewberries in spring as they put on the first new growth of the year. Spread 5 lbs. of 20-20-20 fertilizer along each 100-foot row. Water the bed after fertilizing.

Prune out the canes that just finished fruiting in late summer each year, removing them at the base. Thin out the new canes that are growing in along the ground and have yet to fruit, leaving the healthiest six canes on each plant.

Train the remaining canes to the trellis. Wrap the canes around the wires, staggering the canes so one cane goes along each wire in one direction. Trim back any canes that grow more than 10 feet long.