Elderflowers show their pretty and fragrant blossoms between about May and July. Enjoy preparing this delicious treat during this time.  But, if you fancy elderberries, you must wait until late summer. Elderberries are ready for harvest around August or September, depending on weather conditions. They then have a blue-black or deep red color. Harvest only umbels on which all fruits are entirely colored. To do this, cut off the entire umbel and remove unripe and spoiled berries.