How to Increase the Yield of Wild Raspberry Plants

Pull weeds that grow around the wild raspberry bush, since weeds compete with the plant for resources. Wear garden gloves to protect your hands and remove all weeds.

Layer 2 inches of compost or manure around the base of your plants to add nutrients.

Look closely at the canes of your raspberry bush. Your goal is to differentiate the first-year cane from the second-year (or older) cane. The 2-year-old cane bears berries, then dies, never to produce more raspberries. On wild berry bushes, this can lead to a tangle of old growth that chokes the plant and reduces air circulation. One-year-old canes will be green and supple; older canes are tan in color and have a "bark" covering the stem.

Cut off all second-year canes at the base. This opens up the bush to air circulation. Pruning won't lead directly to more berries, but it will go a long way toward ensuring your plant stays healthy and toward giving the growing canes the resources they need to bear fruit (since there's less competition). The best time to prune is late winter or early spring, according to the University of Maine.

Give the berry bush 1 to 2 inches of water per week from the spring to the fall. Withhold this water only if you receive adequate rainfall during that period.

Fertilize wild raspberry bushes using 1 lb. of 10-10-10 fertilizer per 100 square feet of berry canes. Scatter dry fertilizer on the soil and water to disperse nutrients. Do this once in April and a second time in June, advises the University of Maine.

Watch the berry bushes for signs of disease or plant pests. If the leaves develop a powdery white coating, your wild berry bush has powdery mildew and you should not eat the berries. If the leaves develop blotches or discoloration, your plant may have mold or another disease. If you find insect pests, consult your county extension agent for help identifying the insect and determining what insecticide is approved for pest relief in your community. Not only do pests and diseases harm the plant's growth, they impact fruit yield and quality.

Harvest your berries when they turn red. If you're not sure how they're doing, sample one to make sure it's sweet. When you can easily separate the fruit from the cane, it's ready to harvest.