Hydrangea macrophylla, the pink and blue hydrangea are commonly known as Big Leaf or Mophead. Most of these bloom in July or August in either blue or pink, although a few varieties
If you have pink blooms and would like them to be blue, simply amend the soil with aluminum sulfate. Your local garden center will have aluminum sulfate.
Apply it around plants that are at least two years old and be sure to water the plants well before applying. One tablespoon of aluminum sulfate per gallon of water is recommended, and can be applied throughout the growing season. Don’t overdo it though. Too much can burn the roots and harm the plant.
If your soil is naturally acidic but you want pink hydrangea blooms, a fertilizer high in phosphorus will prevent the plant from taking up aluminum and the blooms will become pink.
Prune your macrophylla hydrangea right after they bloom. They start producing flower buds for next year as soon as they finishing blooming, so if you wait too late to trim them you’ll cut off the flower buds for next year.
PeeGee hydrangeas bloom white then turn pinkish. PeeGee’s bloom on the current years growth. Therefore you can trim them from the time they quit blooming until mid spring. PeeGee is
hardy up to zone 3 and can also be trained into tree form.
Annabelle hydrangeas have white blooms that can reach up to ten inches in diameter. They also bloom on new growth so trim them just as you would PeeGee.
Oak Leaf hydrangeas like sun but they do not like wet feet. They also bloom on old wood, and should be pruned after blooming but before they start to make new buds in August.
Judy Burke says
Mike my dappled willow looks dead. No new leafs, only new shoots at bottom.
Also the trunk bark in split and there is a black pasty stuff in a few places. What can I do if anything? Thanks, Judy in Rosemont Illinois.
I’d give it a couple more weeks then prune away the dead and hope for the best. That’s really about all you can do.
Mary & Keith Raynor says
Hi Mike, I have a question. We bought our house 3 years ago, there was a huge overgrown hydrangea in corner of front yard. So, I trimmed it hard. Didnt bloom following year but, this year got lots of blooms. Problem is there is alot of dead wood in the bush. Dont know what to do, can I cut them at the base? Can I cut them now while its blooming? Its about 5′ by 5′. Its early July, pretty sure its a Nikko Blue, Any advice would be appreciated. Thanks, Keith and Mary P.S. our cuttings are doing great, patience is what I needed, lol ! You were right,lol
Keith and Mary,
Glad to hear that the cuttings are doing great. You can cut that dead wood out of that Nikko Blue anytime you want, you won’t hurt the plant.
Carrie King says
I have my hydrangeas in part shade and part sun they gave only bloomed once. I know I need to move them I need to know where is the best place.
Carrie, partial shade should be fine as long as they get several hours of sun each day. I grow them in full sun and they love it.
I had mine in full shade and they still bloomed…..
They are the type that bloom on old wood though, so I don’t know if that made any difference.