Show Date: 18 Aug 10
The fun doesn’t end with ‘Annabelle’! Hydrangeas, that is…
Hydrangea macrophylla or Big Leaf hydrangeas offer 2 types. Mopheads and Lacecaps.

Hydrangea Macrophylla Mophead
The above picture is ‘Nikko Blue’. This baby needs amended soil to get those blue blooms here in Minnesota. Our soil is too alkaline for them. To do that you need to use aluminum sulphate. And you have to do it every year. Water the soil around your plant well. Mix one Tblsp. aluminum sulphate with one gal. of water. You can do this a couple of times a year. Elemental sulphur doesn’t work as well. Your goal is to have your soil at about 6 pH. Most MN soils are around 7 pH.

Hydrangea Macrophylla Lacecap
Lacecaps are really hardy to zone 5 but as long as you protect those buds from a late frost, you should have blooms. They are much more delicate than the gaudy mopheads.
Hydrangea macrophylla bloom on new and OLD wood. So if they suffer some winter kill, you’ll still get some blooms.