Hydrangeas are known for their clusters of bright flowers that turn blue in acidic soil or pink in basic soil due to the absence of aluminum. Hydrangeas typically bloom in the spring, producing flower crowns at the tops of the previous year's growth. If this growth is damaged by winter cold or late-spring frosts, it can prevent the blooms from forming. The most reliable way to ensure that hydrangeas bloom in the spring is to protect them from the cold of winter and late-spring frosts.
Drive tomato stakes into the ground with a rubber mallet so that they surround the hydrangea bush. To make sure that the stakes are secure, drive them at least 1/3 of the way into the ground.
Wrap chicken wire around the tomato stakes to form a cage around the hydrangea bush.
Secure the chicken wire to the tomato stakes by hammering fencing staples through the wire and into the stakes.
Fill the cage with fall leaves. The leaves will insulate the bush against damaging frosts while still allowing air to circulate around the bush.
Store more leaves to add to the top of the cage as the current leaves settle. This will help keep the delicate tips of the bush from becoming exposed.