Question
I live in zone 8, about 2600' elevation in the western foothills of the northern Sierra Nevada (between Sacramento and Truckee).

I feed all my roses organic fertilizer, plus whatever compost I can make.  The canes look strong, lots of leaves and lots of blooms.  But they only last a couple days in the vase.  (I use cut flower food, cut on the diagonal, etc., and they are not in sunlight or drafts.)  My roses from these same bushes used to last 5-6 days in the vase.  Is there a particular nutrient they might be deficient in?  Should I perhaps rotate brands of organic fertilizers?  (last few years have been with Gardens Alive! brand)

Answer
Vase life on rose flowers is programmed into it's heritage. The breeder usually doesn't bred for vase life unless it is a florist rose. Some garden roses have a long vase life, others shatter in a day. Roses picked in the spring often have a longer vase life then those picked in the summer. Roses picked in th heat wilt much quicker. Vase life depends a lot on when you pick the rose plus whether or not you have watered the rose bush before you cut them. The best time to pick a rose is in the early morning when you have watered the bush the night before. Pick the rose when the bud has started to open and the sepals have turned down. If the rose has lots of petals then do the same but wait until the bud has opened more. After picking them place them into water right away when you are in the garden. Fill the vase with warm water and add two drops of bleach and a teaspoon of white sugar. Then cut the rose stems on a slant. Change the water every three days.