Plant Doctor Archive

Controlling boysenberries

I HAVE quite a few exotic fruiting plants, including a boysenberry vine which has sent out amazing runners along my iron boundary fence. I wasn't able to cope with it over the summer, owing to a shoulder operation, and now the suckers have rooted into the sandy soil. Will they grow into productive plants if I cut them off and transplant with a length of stem attached? I feed everything liberally with horse manure and have tied most of the plant to the fence along the wall.

THIS natural method of propagation, when a stem produces roots where it comes in contact with the soil, is called layering. Given ideal conditions, each piece can eventually become a productive plant, though it will probably take two to three years before you get much in the way of fruit.

Carefully dig up the rooted stem and cut it into separate plants. Make sure you get the "polarity" right - the roots should be on the end of the stem that was closest to the original plant. And make sure each new plant has at least two good strong buds.

Once they're established, each winter cut the boysenberry shoots that fruited back to ground level in summer, and tie young unfruited ones to the fence in their place.

And keep on using that horse manure. Mixed in the soil for new plants, or as mulch around established ones, it's great for most berryfruits.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.