As for essential oils that have long shelf lives usually, they are the thicker ones, such as Cedarwood, Sandalwood, Patchouli, Vetiver and a few others. Exception to this thick oil quality will be the essential oil of Rose Otto.
The season for them is generally a short one. Begins in early July and last for 2 to 3 weeks. Black raspberries tend to ripen before most red raspberries varieties expect for the early ripening summer ones.
Cut the plant to the ground. The easiest way to prune fall-bearing raspberries is to cut everything down to ground level in spring. Instead of having a summer harvest, you will only have one harvest in the fall. This fall harvest may produce higher quality raspberries.