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Macrophylla freeze reminder for April 1-7!!

8 years ago
last modified: 8 years ago

Hi all! Checking back in... Just as I'd previously mentioned, due to El Nino this past winter, it appears like a TON of our hydrangeas' stems have indeed *not* bitten the dust and are loaded with green (and some reddish/dark) buds ready to put out a ton of flowers this season. And it also looks like some select areas that have been experiencing many temps in the 60s-70s will get a few nights below freezing in the next week (28 degrees or just below). With temps below 30 degrees for even a few hours, you *must* take proper care to insulate Hydrangea Macrophylla that have already broken dormancy during these warm temps. If you do not do this, you risk death to some or all of the new leaf growth and some buds.

You can accomplish this in three easy steps.

1) Using a rake or your hands, heavily mulch the bases/crowns (I used loose dirt and last year's brown mulch) til you can't see any green shoots that have sprung up.

2) Take loose leaves or other dead plant matter from last year and pile up to a height of about 12-18" (pick it up in bundles and just drop overtop).

3) The day before the night the freeze hits, find as many old sheets, blankets, plastic sheeting, etc and cover the plants. Use rocks or bricks to keep them from blowing off. The warmth of the daytime heat and decomposing matter should be sufficient to keep enough cold air outside the covering.

I was able to clean up some beds, prune roses, and cover 50 or so plants in about 3 hours' labor.

[You can take the blankets off during warmer spells, but do NOT remove the plant matter until the last danger of frost has passed]

Here are some of my "tents". In the left rear you can see I used some dead H Paniculata flower heads from last season - they are very rigid, don't blow away, and make great insulation!

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