Perennial Wisdom - Advice on Propagating Raspberries

What could be better than raspberries? More raspberries, of course, and if you have raspberry plants, you can easily propagate them to attain more plants and berries. With raspberries, stem cuttings may not be entirely straightforward because only one kind of stem (or cane) can be used for cuttings. In fact, you may not succeed with raspberry stem cutting unless you use primocanes, which are the canes that started their growth and bore fruit in the season.

You may want to avoid floricanes, which are last year's primocanes that can turn brown and woody after bearing fruit, while primocanes are green and pulpy inside. Floricanes typically have shorter spaces between sets of leaves than primocanes do.

Once you've identified the correct canes to cut, you could start by gathering a few supplies for the propagation process. You can use sharp scissors or hand pruners and pots filled with moist, well-draining soil, ready to receive cuttings. Washington State University (WSU) Master Gardeners recommend soaking pots of soil in a few inches of water before placing cuttings in them. Protect your hands from stickers with gloves. Rooting hormones are optional since raspberry cuttings can root readily without it.

 Fall can be a good time to take primocane cuttings for propagation because they usually need cool temperatures to put out roots. WSU Master Gardeners suggest cutting a piece of cane with at least four leaf nodes on it. Then, cut the stem below each leaf node. Remove excess leaves so the cut can put its energy into producing roots rather than maintaining them, and be sure to remove leaves from nodes that will be buried. Master Gardeners also recommend inserting each cutting all the way into the soil to the bottom of the pot after dipping cane pieces in rooting hormone, if desired. Tamp soil for firm support around the cane.

Continue to keep the soil moist as you wait for roots to emerge, which could take up to two months. Keep the plant out of direct sunlight but in a bright spot. It's unusual for raspberry cuttings not to root, so you can likely look forward to new raspberry plants to put in the ground in the spring.

Many raspberry enthusiasts plant the suckers that grow from primocane roots. But using primocane cuttings for propagation can be a practical option when suckers aren't yet available or when you want more plants than natural suckering alone would provide. 

Resources: Find resources for this and more of our gardening columns at extension.wsu.edu/stevens/gardening/general-gardening-information.

The WSU Extension Master Gardener Program trains volunteers to be effective community educators in gardening and environmental stewardship. Master Gardeners provide information generated from research at WSU and other university systems. Master Gardener Kathy Hansen is a writer and educator living in Kettle Falls. Visit us and bring your questions to the Chewelah Farmer’s Market, every other Friday, 11 a.m. to 3 p.m. (next one is Aug. 7), and the Colville Farmers Market, every other Saturday, 9 a.m. to 1 p.m. (next one is Aug. 8). Pressure canner gauge testing is also offered at the markets through September.