Almost everyone dries hydrangea at the wrong time of year. A head cut in July, at its brightest, will shrivel and go the colour of a paper bag within a fortnight, no matter what you hang it in.
The head has to dry on the plant first. From late August into September the flowers stop being papery and go slightly leathery to the touch, and the colour shifts — pinks turn towards rust and antique green, blues towards a grey-violet. That is the moment.
The method
Cut in the morning, once the dew has gone. Take a long stem and strip every leaf off it; leaves hold moisture and rot before the head dries.
Now the part that surprises people: put the stems in a jar with about five centimetres of water and leave them somewhere out of direct sun. The flower dries slowly as it drinks the last of the water down, and slow drying is what keeps the colour. Hung upside down in an airing cupboard, hydrangea dries in three days and goes brown. In water on a shelf it takes two or three weeks and keeps most of what it had.
Do not top the water up. When it is gone, it is gone, and the head should be crisp at the edges by then.
Which varieties work
Mophead and lacecap both dry well. Paniculata — the cone-shaped white ones that fade to pink — dries best of all and holds colour for years.
Anything sold as a florist hydrangea, forced in a greenhouse for the spring market, dries poorly. The stems are too soft. If you are buying specifically to dry, buy in September from a market rather than in April from a shop.
Afterwards
Dried hydrangea is brittle and it hates humidity. A damp autumn will make a dried head go limp and it does not come back. We keep ours away from the kitchen and the bathroom for that reason.
Sun is the other enemy. On a windowsill it will fade to beige in one summer. On a shelf across the room it holds for two or three years.
Dust it with a hairdryer on the cold setting from about thirty centimetres. A cloth will take the florets off.
One trick worth knowing
If you want to keep a specific colour rather than the antique version, cut in early September but leave the stem in a jar of half water and half glycerine instead of plain water. The stem draws the glycerine up into the head, the petals stay flexible rather than going crisp, and the colour holds closer to what it was.
The head will never be quite dry to the touch afterwards. That is the trade, and for a wedding piece it is usually worth making.
