I am helping a customer with some custom stationery and coincidentally she needs blue hydrangea flowers for her upcoming party in July in Michigan. I live in the northeast and know nothing about Michigan, but I assume they can grow hydrangeas there since we can grow them here.
I don’t run a flower shop or sell flowers (only images on paper) but I really wanted to help this woman out. My first bit of advice would be to check with a florist. Or maybe every florist you can find in your area. Florists have the scoop on cut flowers. Since the party will be in July, there certainly should be some flowers available. Hydrangea shrubs in the landscape will have flowers on them by then, so a greenhouse grower should certainly have blue hydrangeas for the flower shops. I would think so anyway.
Also, I have mentioned this before, local nurseries fill their shops with hydrangeas (and especially blue ones) in time to sell for Mother’s Day in May. They won’t be cheap, but it might be a nice addition to have pretty, potted plants set around for the party. Afterwards they could always be planted in the yard.
Waiting until July to buy blooming hydrangeas is risky because the stores and nurseries may be sold out. I know that I bought hydrangea shrubs in Fall here, which were discounted. They had no flowers but were nice, healthy plants. To be on the safe side I would buy them at Mother’s Day and carefully keep them growing until the party. Then the flowers could be cut to use in vases for decorating. (Use the hot water method to preserve them.)
I always wondered if there was a secret to keeping hydrangea flowers fresh once they’ve been cut from the bush. It seemed that sometimes my flowers would last a few days, but usually they would wilt quickly once I added them to a vase.
Hydrangeas have a sticky substance in the stem and once they are cut the goo blocks the stem and it can’t suck up the water as needed. To keep hydrangeas fresh and make them last, if you are cutting them yourself, you must have a vase or bucket of water handy to put them in instantly when making the cuttings. Once you have your cuttings, take them inside and move the flowers from the bucket / vase to another container of HOT water and leave them for 10 minutes. This clears the inside of all that sticky stuff so the water will be able to travel up to the bloom. I have done this successfully and my hydrangeas did then last for days afterward.
If you are planning to use hydrangeas to decorate tables or as a centerpiece for a special event, be sure to cut them, and use the hot water method described above, as close to the event time as possible. If you have room in the refrigerator, keep them cool (in water) until needed.
If the bouquet is for decorating your home, be sure to change the water each day to keep the bouquet fresh.