HYDRANGEA WINTER PROTECTION

I woke up to a very dark 44 degrees F this morning, a stark reminder that I need to get organized to do some hydrangea winter protection. Those that aren’t planted in protected locations as I described in an earlier blog post need a little help if I want to give them their best chance of having their flower buds make it through the coming winter. Scroll down to that older post to the “conclusions” section.

Shrub covers for hydrangea winter protection

How exactly do you protect your hydrangeas for winter? One option is to use shrub covers. When properly installed, they safely shield your plants from ice and snow.

The second use of shrub covers is to make your plant think it lives in a warmer zone. You can do this by insulating it from fluctuating temps that can blast the flower buds. That way, even if your plant gets blasted by a freeze, that extra layer might just get it through. Of course, you need to wait until your plants have dropped all their leaves on their own before you can cover them. 

Take the time after leaf drop (the signal that your plant is now completely dormant) to clean up the base of the plant. You want to prevent the fungal spores that cause leaf spots from overwintering. That small chore will stop the spores from reinfecting your plants next season when conditions are ripe. This is also a great time to add some mulch to keep moisture in and prevent the plant from heaving during any warm spells.

It may be too early in your part of the country as it is for me to do any hydrangea winter protection. But it’s not too early to get those shrub covers lined up ’cause by the time you need them, you might not have enough time to get it all done.

Make an A-frame from discarded pallets for hydrangea winter protection

What does a shrub cover look like? It can be an “A-Frame” made from discarded wood pallets you can salvage from local stores, or one you build on your own. DIY plans and ideas are all over the internet.

DIY A-Frame made from pallets

You can simply leave the A-Frame bare to shunt off snow and ice. However, for colder areas the A-frame makes a great base to drape a tarp, insulating cover, bubble wrap, etc. If you do that, make sure you secure the covering against the weather with string or a bungee cord.

Drape your hydrangeas for winter protection

Another kind of winter protection can be an unframed drape held by the stems of the plant. Here’s one available at several on-line shopping sites:

Shrub cover held by plant stems

Make a DIY cage for hydrangea winter protection

The winter preparation for hydrangeas I see most often is a DIY version made with chicken wire and a few stakes. You build a cage larger than your plant and then stuff the opening with leaves, straw, pine needles, etc. making sure you get the insulating materials down and around the bare stems. This takes a bit of care as you want to avoid damaging the tips where the sleeping buds lie.

 Hydrangea in DIY Leaf Cage

Insulate

Depending on where you live and where your plant is sited, you may want to insulate your cage by wrapping with bubble wrap or some other material. Also note that your internal packing materials (leaves, etc.) will settle during the winter. So many gardeners secure a cover over the top of the structure.

Make a Cover

Cut a piece of Styrofoam (from craft stores) slightly larger than the top of the cage. Fit it above the cage with a slight overlap and secure it to the chicken wire with twisties or bungee cords. Otherwise, heavy snow and rain will weigh it down and it will crush your plant. You can also use plywood or scrap lumber for this top. Make sure it’s not too heavy for the chicken wire to hold it up. If that’s too much for you, you can keep an extra supply of bagged leaves at the ready to top off your masterpiece from time to time.

Get the prep done NOW

Let the plants harden off over the next few weeks while you get things ready. But don’t wait for the last minute when time is short to get these items lined up. There’s no way of telling when the on-line suppliers will run out and how much time you have to get organized for this task. You can be ready to spring into action more quickly when you have your covers all planned out and ready to go. Plus it is more pleasant to work outside now before the temps really plunge.

The Need To Protect Other Hydrangeas

Gardeners frequently ask me about protecting other old wood flowering hydrangeas, e.g. oak leaf and climbing hydrangeas. First of all, these plants are usually much harder to wrap. I have no clue how to wrap a climbing hydrangea – unless it was a new, small plant. And oak leaf hydrangeas can be quite large.

Here’s the good news: you don’t have to worry about them unless you grow them in a zone colder than their hardiness rating. In my 30 years at my zone 5B home, those two varieties always flower despite some significantly frigid winters. They have always come through.

This next photo gives you a better idea of how it happens. A sudden 2020 freeze blasted the big leaf and mountain hydrangeas. You can clearly see what happened to the big leaf hydrangea in the back . The foliage of the oak leaf hydrangea in front was completely untouched by that freeze and ensuing cold nights.

I cover the subject of winter protection in my best selling book, Success With Hydrangeas, A Gardener’s Guide. You can order a signed copy here. It makes a great holiday gift for the gardener in your life.

Hydrangea happiness can’t start soon enough!

OTHER ITEMS TO NOTE

I am booking virtual and in person presentations for 2022 and beyond. Covid taught us that geography can be irrelevant. Now I can easily discuss your favorite gardening topics from my home base to anywhere you are. Just click HERE to start the ball rolling to have me present to your group. And if any of the upcoming dates I have are public (very few are), I will post it on the calendar page of this site.

Thanks for reading!