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.
When to harvest berries depends on the berry type, too. Strawberries are usually ready to pick in June and may be harvested for three to four weeks. They are fully ripe when the entire berry is red. Elderberries mature in the mid summer, as do most other types of berries. Blackberries, however, are often not ripe until late August and into September.