We have had a few nights where the temps have dropped into the high 30s, a sobering reminder that it’s time for preparing hydrangeas for winter. Specifically, time to wrap some of my bigleaf (macrophyllas) and mountain (serratas) hydrangeas. Those that aren’t planted in protected locations as I described in my other blog posts, HERE and HERE need a little help if I want to give them their best chance of having their buds make it through the coming winter to see flowers in 2020.
Exactly what does this mean right now? SHRUB COVERS: something to safely protect the plants from ice and snow, maybe even give them a few degrees of insulation.
PREPARING HYDRANGEAS FOR WINTER WITH SHRUB COVERS
The objective of shrub covers is to make your plant think it lives in a warmer zone. You do by insulating it from fluctuating temps that can blast the flower buds. Of course, you need to wait until your plants have dropped all their leaves on their own before you can cover them. That leaf drop signals the plant is fully dormant. Take the time after leaf drop to clean up the base of the plant to prevent fungal spores from overwintering. That small chore will stop the spores from reinfecting your plants next season. This is also a great time to add some mulch to keep moisture in and prevent the plant from heaving during warm spells you might have.
Taking the need for dormancy into account, it may be too early in your part of the country to install these covers. But it’s not too early to get those shrub covers lined up. By the time you need them, you might not have enough time to get it all done.
WHAT DOES A SHRUB COVER LOOK LIKE?
A simple A-Frame made from discarded wood pallets is a popular DIY solution to prepare hydrangeas for winter. Lots of stores pile them up at their back door which you can salvage. Many gardeners like to build one on their own. DIY plans and ideas are all over the internet. I found one at https://www.gnhlumber.com/diy/shrub-cover/.
You can 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 or insulating cover. If you do that, make sure you secure the tarp or cover against the weather with string or a bungee cord.
UNFRAMED DRAPE VERSION
Many gardeners prepare their hydrangeas for winter with an unframed drape. It’s held by the stems of the plant. It’s usually tethered at the base. Here’s one available at several online shopping sites:
DIY CAGE VERSION
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.
DIY shrub cover made from stakes and chicken wire
INSULATING THE CAGE
Depending on where you live and where your plant is sited, you may want to insulate the outside of the cage with bubble wrap or some other material. Also note that your packing materials will settle during the winter. So many gardeners secure a cover over the top of structure. Cut a piece of Styrofoam (from craft stores) slightly larger than the top of the cage. Fit it above the cage 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. Barring that, you can keep an extra supply of bagged leaves at the ready to top off your masterpiece from time to time.
WAITING TO PREPARE HYDRANGEAS FOR WINTER
Let the plants harden off over the next few weeks while you get things ready. Don’t wait for the last minute when time is short to get these items lined up for installation. There’s no way of telling when the on-line suppliers will run out and how much time you have to get yourself 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.
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!
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