Can I safely use insecticide on Blackcurrant?

We never use insecticides on any of our fruit bushes. We prefer to eat uncontaminated food. What is the reason why you are considering spraying?

Plant garlic round your bushes, and I put a greaseband around the stem to stop pests climbing up. The only bush that had problems this year was sawfly on a gooseberry bush which came from a nursery so take care it's easy to import pests! I will wait till it's dormant and take off the old soil and plant the bush in fresh soil, as they overwinter in the soil.

Our black currant bushes have multiple stems, a bit hard to greaseband them. If it is Blister mite which is a problem (the leaves get covered in red pimples!) then spray the bushes in winter with one of the modern Winter Washes. They are based on natural plant products.