Getting Your Hydrangeas Ready for Winter
If your hydrangeas live in a cold climate, late fall weather is the perfect time for them to harden off, you can use this same time to prepare them to make it through the coming winter.
Exactly what you do depends on what kind of hydrangea you have and where it lives. But the good news is the only ones you really have to worry about are your hydrangeas that flower on old wood. Their flowers have been forming on the plants since August and those are the buds that you need to protect.
For the most part, climbing and oakleaf hydrangea flower buds are more winter hardy than those of bigleaf plants. In my zone 5 gardens, when my bigleaf hydrangeas have suffered winterkill, my oakleaf and climbing have flowered profusely with no protection.
What this all comes down to is the one kind of plant that needs your intervention: bigleaf hydrangea (macrophylla). I call it the troublemaker.
Make an A-Frame for Protection
Snow can be a protective blanket in some cases or it can break and distort the stems when it is heavy and wet. In view of that, one thing to consider is an A-frame to shunt off the snow. It still allows the snow to build up at the base of the plant which can be a good insulator. You can build an A-Frame from a discarded pallet as shown in the photo or buy one. There are lots of DIY plans online.
You can protect your plant by erecting some kind of temporary windbreak. Hydrangea macrophylla buds are killed by icy winter winds which desiccate tender flower buds.
Wrap Hydrangeas for Insulation
Many people wrap their plants to insulate them. The idea is to make your plants think they live in a warmer growing zone. You can use a tomato cage or build a cage with chicken wire/garden fleece/burlap and fill it loosely with leaves. You can even bubble wrap the exterior of this cage, adding even more insulation. I have seen some structures with a Styrofoam cover (purchased from craft stores and cut/fitted to the structure), secured to the top with wire/twisties. It depends on how much protection you think you need.
Some lovers use a large plastic leaf bag filled loosely with leaves with a closed top and no internal structure. However, be aware that moisture build-up is a potential pitfall with any plastic and heavy snow can crush the closed bag – and your plant.
When you wrap your plant, it’s imperative that the removal of your protection in spring is well executed. Do it on a cloudy day when all chances of late season frosts have passed. Remember that the plant might have broken dormancy beneath the leaves so be careful of the tender buds. You might have to provide artificial shade for a few days as the plant adjusts to bright daylight.
True confession time: I don’t do any of this anymore. All of this old-wood blooming angst was too much for me. I wanted to simplify my life so I donated all of my old wood hydrangea macrophyllas. In came newer reblooming cultivars and hydrangea serratas which are much more bud hardy. Voila! Now when old man winter deals me a bad hand, I still get flowers, albeit a little bit later than June. Plus I think the newer introductions are stunning and are better plants on all counts. As always, the choice is yours.
A few of the newer Hydrangeas from NGB members include Hydrangea Diamond Rouge™ and Hydrangea Miss Saori
Here’s to a benign winter and hydrangea happiness!
Should I bring my big leaf red hydrangea in for winter or can I plant it outside. We live in zone 5, I have two other hydrangeas that are slow coming back after winter. Any help or suggestions. We just moved to this area and in another zone 5 my hydrangea was great. Soil? Or where I am planting them? Thank you
You should plant your hydrangea outside for the winter. Do it as soon as possible. Once frost hits hydrangeas start to go dormant, transferring energy into their roots for the following year. Giving your freshly planted hydrangeas a period to get established in their new home will increase overwintering success. You can learn more from this NGB author at https://www.lorraineballato.com or at https://endlesssummerblooms.com/resource/hydrangea-planting-and-care
I live in Missouri and purchased a pink hydrangea in a put I bought a large planter and planted it in that until the warm weather was more consistent. While inside the flowers began to turn brown and dry up. I watered it often but seemed like it was just unhappy inside. Now some flowers are missing, some are green, and one small bunch is pink. I planted it in my backyard and am hoping it’ll make a full recovery. Any tips to get beautiful flowering blooms again?
We asked author Lorraine Ballato your question and here is her response…
“It sounds like this was a “gift” plant that maybe was around for Mother’s Day, Easter, etc. If so, the browning is highly unusual as these plants are meant to be enjoyed indoors for a couple of months. Leaves brown out when a plant is either hit by a herbicide or has some serious soil issues. The herbicide possibility could have been something that was applied before you bought the plant. It takes a few days or so for it to show up. The soil issue is highly unlikely unless someone poured something into the pot, unbeknown to Samantha. That could have happened long before purchase.
Now for the cure. If this is a gift plant, don’t expect much as these plants are produced for their one-time show.
But for the determined gardener:
First inspect the roots to be sure there are some that are alive;
Then have the soil tested where the hydrangea is now planted. Amend as necessary based on the results and recommendation from that test;
DO NOT FERTILIZE as you don’t want to push new growth. The objective in the short term is recovery;
Add compost which is always a good idea as the microbes can do wonders for soil and plant health.
Be sure to mulch the plant well so it doesn’t dry out. But be careful of overwatering. When you stick your finger in the soil, it should be damp at your second knuckle. If not, then water;
Try to water deeply and intermittently to encourage the roots to go deep to seek the water.
If the plant pushes new flowers this season, be very grateful. But if this is a gift plant, it most likely flowers on old wood: it needs to set its buds later this season and then retain those buds through the winter until spring 2022. Most gift plants are produced for their one-time show which takes enormous energy to the point that the plant needs a full season to recover. So if all things go right, getting flowers in 2022 will be a bonus.
My hydrangea has started looking like it is dying with the colder weather. Do I need to pull it up and plant a new one after winter?
Thank you for your question. We asked Lorraine Ballato, the author of this blog and she said:
“I can understand why you might think your plant is in trouble. Many gardeners have the same concern this time of year. But you can rest easy. What’s happening is the plant is in a dormant stage as it rests up for next season. If you want to test this, scratch any stem with your fingernail. The ones that come up green are alive. If you find no green beneath the outer layer, then it is dead. So the best thing to do is nothing and let it sleep: isn’t that great?
I strongly advise you to wait until spring arrives in your area of the country before you do anything. At that time, your plant’s live stems will begin to show green at the point where the leaves emerge (node). Only then will you be able to accurately determine if your plant died and needs to be replaced. In many cases, even with significant winter kill, a hydrangea that is well cared for will bounce back and produce new stems. If your plant is a rebloomer, those new stems can be the source of magnificent later season flowers.
I discuss much of this throughout my popular hydrangea blog https://www.lorraineballato.com/blog/ which is available free of charge to anyone who signs up. I also address similar issues in my best selling book, Success With Hydrangeas, A Gardener’s Guide.”
A few years back I literally killed a gorgeous blue hydrangea by cutting it all back as there were dead flowers and leaves. Then 2 years ago I re-planted and they made it through their first winter. Beautiful flowers in summer/fall. They have big leaves. Deer would come by at night and eat the plant. I am left with old wood but plant is alive, though its big leaves are brown and so are the remaining dead flowers. We are in the Smokie Mountains. Temps will drop to mid-20’s at night and up to mid 40’s during the day. What should I do to save them?
We asked Lorraine Ballato, the author of this blog post and book on Hydrangeas your questions, and here is her response:
“Variations in elevation, rainfall, temperature, and geology in these ancient mountains provide ideal habitat for over 1,600 species of flowering plants, including hydrangeas. Your plant should survive, i.e., live under most conditions. The best way to figure that out is to go to the USDA hardiness map at https://planthardiness.ars.usda.gov/PHZMWeb/ and plug in your zip code. That will give you a GUIDELINE re a plant’s ability to survive.
Assuming you’re in at least zone 5, your hydrangea macrophylla will live through a few cold nights so you don’t need to take extra steps to protect it. A recent blog post on how to protect your plant can be found here: https://www.lorraineballato.com/time-to-prepare-hydrangeas-for-winter/
However, for a better chance at flowers, you might want to consider donating that plant and replacing it with one of the newer varieties that rebloom. That means that if the plant loses its first pass at flower buds to weather or deer, you have a second chance for flowers in the current season from mid-summer on. Those rebloomers — unlike the hydrangeas of old — have the ability to grow new wood in the current season which don’t need a cold set period for those flowers. Unless of course, your deer decide to snack on them. Then all bets are off.
I would strongly urge you to use one of the many deer repellent sprays on the market. They all work, some better than others. None are harmful to the plant, the environment, pets, etc. But you do have to hold your nose and be sure to be upwind of the spray. The key piece here is to start retraining your deer to go elsewhere for their meals.
The other recommendation is that you go to a dedicated hydrangea blog for other info on how to protect plants, how to prune them., etc. That can be found at https://www.lorraineballato.com/blog/. There’s a convenient search bar that will let you go directly to your area of interest to get answers, recommendations, etc.
I believe hydrangeas are magnificent plants and are worth whatever we need to do to get the benefit of their presence in the garden. It doesn’t take much and the breeders are continually giving us new and better options. So keep at it and you will be rewarded handsomely!”
If you live in Louisiana, where it sometimes gets to 32 degrees. We have 2 hydrangea plants in 2 pots. Do we still have to cover them?
We asked Lorraine Ballato, author and Hydrangea expert your question and here is her response, hope it helps:
That answer will depend on several factors:
First is the growing zone. The USDA map says LA is zones 8a-10a. Generally speaking, all hydrangeas should be fine within that range and all will survive 32 degrees F. The ones in zone 8 might burp every now and then, but for the other zones, heat is the enemy.
Second is what kind of hyd is it?
If it is an oak leaf or mountain hyd, those buds should be able to survive one or two freezing events with no protection as the buds are more hardy.
A gardener is completely safe from winter temps if their plant is a panicle or woodland/smooth hyd since they flower on new wood only. There are no buds on the plant for ol’ man winter to attack.
If it is a big leaf hyd (macrophylla) it might need some help, not to live but to flower. Let me explain: that particular species flowers on old wood (stems that were formed in the previous growing season) so those buds must make it through the winter unscathed. If that plant is exposed to icy, prevailing winter winds, the buds could get frozen off. When they are most susceptible is when the dormant buds open early (from a winter thaw, for example), and THEN freezing temps arrive.
One of the best things a gardener can do is make sure their big leaf hyd are repeat bloomers. In that case when buds get frozen off, the plant has the ability to form new buds and flowers before the end of the current season. So you can still get flowers, albeit later in the season with those plants.
If you go to my blog, I cover several ways to protect them in my Nov 6 blogpost, “Time to Prepare Hydrangeas for Winter,” https://www.lorraineballato.com/time-to-prepare-hydrangeas-for-winter/
When do you stop watering to allow plant to go dormant?
Since Hydrangeas need to stay hydrated for winter, it is recommended to continue to water until the ground is frozen