Hydrangeas are beautiful flowering plants with dramatic blooms that provide color and drama in the summer garden, but they can be fussy if they don’t get the proper care and attention. Proper hydrangea care for late winter is key. Improper pruning and other common mistakes, compounded with difficult weather, can lead to disappointment. Luckily, my podcast guest this week, Lorraine Ballato, is a hydrangea expert who will help you overcome the biggest hydrangea challenges.
Lorraine is a garden writer, speaker, photographer and all-around authority on hydrangeas. In fact, she wrote the book on hydrangea care: “Success with Hydrangeas: A Gardener’s Guide.” She says hydrangeas are one of those plants that are a bit of a diva and are persnickety about the approach gardeners take when it comes to caring for them. She reminds gardeners to keep in mind that what works in one region won’t be the best approach in another. The best thing to do for a hydrangea in Washington in winter could be the absolute wrong thing to do for one in North Carolina. And, she adds, different hydrangea varieties have different needs.
Hydrangea Care in Deer Country
Lorraine lives in zone 5b, where, in March, it’s quite cold. There are between 2 and 3 feet of snow on the ground, and in that snow she can spot tracks, which means deer are out browsing.
“If you live anywhere in deer country, as soon as it gets above freezing, and as soon as it’s dry, get out there and spray, because this is the time of year, they start to really ravage everything,” Lorraine advises. The deer are hungry, the does are pregnant, and the time to train them that your garden is not their salad bar is before all the snow is gone and before they give birth. The does will train the fawns where to eat, so don’t wait.
Make sure you are upwind when applying sprays. “You do not want to be downwind of any deer spray that you use,” Lorraine says — and she means it. As soon as you’re done spraying, whatever clothing you’re wearing should go right in the wash.
In addition to spray repellents for deer, there are systemic repellents. The systemics are applied when plants are actively growing. The plants take up compounds such as denatonium benzoate through their roots, infusing the leaves with a bitter flavor that will deter deer. These are not meant for food crops, but can be applied to ornamental plants.
I’m in zone 7b, where dormant shrubs will be leafing out soon, and that’s just candy for deer. I have a family of 13 deer that enjoy my property, where I don’t have deer fences. For fence-free solutions to keep deer from eating your vegetable garden and ornamental plants, you can listen to my conversation with landscape design expert Karen Chapman on how she keeps deer away from the plants on her rural property in the Pacific Northwest.
Prepare Before Pruning
Before setting out to prune shrubs, make sure to have the right tools for the job and that they are all sharp and disinfected. Tools that touched diseased plant material the prior year may still be carrying those pathogens and can transfer them while cutting.
Lorraine also recommends disinfecting tools between pruning each plant to prevent the transfer of pathogens. She uses disinfectant wipes or rubbing alcohol in a spray bottle. What she doesn’t recommend is bleach, which is corrosive to metal surfaces.
There are two kinds of pruners, and each is for a different task. A bypass pruner has a scissor-like action, where the blades pass by each other. An anvil pruner has a sharp blade that squeezes down onto a blunt side, in a crushing action.
Use a bypass pruner to cut anything that’s live. It will give a nice clean cut, Lorraine says, noting to cut at a 45° angle. Meanwhile, an anvil pruner is appropriate for deadwood. If one is used on live wood, it will bruise the plant, she warns.
Remember that dormant branches are alive, even though they may not look like it. Some gardeners make the mistake of thinking their hydrangea’s top growth is all dead, so they cut it down to the ground. Lorraine says that’s how they end up with a green bush with no flowers — they’ve cut off all of the flower buds that were going to bloom that year.
To test whether a part of a plant is dead or alive, Lorraine uses the scratch test: Scratch the stem, and if it comes up green, it’s alive. If it comes up brown, it’s dead.
Every cut a gardener makes will stimulate new growth, Lorraine says. Pruning before the weather has warmed in spring can cause a plant to wake up too early. That will take energy away from that plant that it needs when it truly breaks dormancy, plus that new growth will be vulnerable to the cold. If it dies back, the damage will open the plant up for pests and disease.
In a warmer zone, go ahead and take care of that dead, diseased or damaged wood, Lorraine says. Otherwise, she advises, if you feel the urge to prune now — go on a fishing trip instead!
Lorraine points out that ice, snow and cutting tools don’t mix, even on a 50° day. It’s not worth the risk, and the wait will be the best thing for the plants too.
New-Wood Hydrangeas and Old-Wood Hydrangeas
Not every hydrangea has the same growth habits. Some bloom on that year’s new growth, while old-wood types bloom on the previous year’s growth.
Prune a new-wood hydrangea in spring, and it will grow new buds and then flower. But pruning an old-wood hydrangea in spring will remove the existing buds, and it won’t flower that year. If pruning old-wood types at all, do so right after its buds begin to flower in summer. Look for the “broccoli,” Lorraine says. That’s what buds look like as they get closer to flowering. Leave the broccoli be, and only cut off wood that is clearly dead or diseased.
Clues to Identify Hydrangeas
Woodland or smooth hydrangeas (Hydrangea arborescens), like Annabelle, Incrediball and Invincibelle, and panicle hydrangeas (Hydrangea paniculata), like Limelight, are a few examples of new-wood hydrangeas. But if you didn’t pick out hydrangeas yourself, you may not know the name of what you have. Perhaps you moved into a new house and inherited plants. In that case, Lorraine says to not do anything the first year: “‘Do nothing’ is a good strategy until you get your head squared around what you’ve got in the garden.”
There are some clues to look for to determine whether a hydrangea is a new-wood bloomer or an old-wood bloomer. For example, a hydrangea with conical-shaped blooms may be a panicle hydrangea, which a new-wood variety — but it’s also necessary to look at the foliage. The oakleaf hydrangea (Hydrangea quercifolia) is an old-wood bloomer that may also have conical blooms.
A hydrangea that is blue — or that turns blue with a soil acidifier — is always going to be a bigleaf hydrangea (Hydrangea macrophylla). Most bigleaf hydrangeas bloom on old wood only, but the Endless Summer varieties bloom on both old wood and new growth.
A hydrangea with pink pompom blooms, known as mopheads, may be a bigleaf hydrangea, but it could also be a mountain hydrangea (Hydrangea serrata). Mountain hydrangeas bloom on old wood.
Hydrangeas with lacecap (flat) blooms could be either a mountain or a bigleaf variety, so lacecaps are not enough evidence to act on. Lorraine says to look at the foliage to get a better idea, or spend the season observing the plant, taking note of when it blooms and how it progresses. Does it change color? Does it rebloom?
Mountain hydrangeas come from the mountains of Japan and have greater hardiness. They can bloom in years that were too cold for other varieties.
How to Care for a Reblooming Hydrangea
Treat rebloomers as if they are old-wood-only hydrangeas — meaning, don’t prune them at the start of spring. But because they have the capacity to put out flower buds for that season on new growth too, there is a trick to encourage more blooms. After the terminal flower — the flower at the tip of the stem — dies, clipping off the dead tips will encourage growth hormones to move up the plant. The stem will then produce flowers up its sides.
Lorraine says that in very cold climates, like in Minnesota, flower buds on old wood just won’t survive the winter. In those circumstances, the right thing to do is to cut the rebloomers to the ground in April or early May, and encourage new growth, which will bloom later, in mid-July or August.
Cold-climate gardeners may never see flowers if growing hydrangeas that only put on new buds once per year. That’s why reblooming or continuous-blooming hydrangeas are the correct choice for colder climates, according to Lorraine. (Her favorite prolific rebloomer is Blue Enchantress.)
Sun, Shade and Hydrangeas
Historically, hydrangeas were not tolerant of full sun. Some newer cultivars will tolerate full sun — but there are limits.
Bigleaf, mountain, oakleaf and climbing hydrangeas cannot be planted in full sun in the South, Lorraine says. They will fry. The only hydrangea type that can take full sun regardless of geography is the panicle hydrangea, which loves the sun.
Bigleaf and mountain hydrangeas do best with a half-day of sun, preferably morning sun.
Wind and Hydrangeas
Lorraine said it took her about 10 years to learn the importance of protecting hydrangeas from wind in a cold climate. A fence, a shed or a plant with winter-persistent foliage, like a rhododendron or azalea, will block cold desiccating winds that kill flower buds.
Watering Hydrangeas Without Drowning Them
In the afternoon sun, hydrangea foliage can become droopy, which gardeners often respond to by flooding the area with water. Lorraine says to instead take a break, then return in a few hours. After the sun has been off the plants for a while, the foliage will rehydrate and perk back up — assuming that the soil composition is correct, with lots of compost and a good layer of mulch.
Collapsing foliage temporarily is a way a plant protects itself from the beating sun. However, if the foliage has not perked back up hours later, there’s an issue. The soil is not retaining moisture, or some other plant may be sucking up the water faster than the hydrangea can.
Propagate Hydrangeas Through Layering
A stem that touches the ground is an opportunity to easily propagate a hydrangea. It may be that the stem grew too heavy or something obstructed its growth. No matter the reason, it is primed to be separated into a new plant.
In spring, give the underside of the stem a cut, and then lay a rock on top to weigh the stem down, maintaining its contact with the ground. By July, give it a tug, revealing all the roots that have grown from the cut. Now you have a rooted cutting, ready to be transplanted elsewhere.
Controlling the Color of Hydrangeas with pH
Not all hydrangeas can change color, but those that do are influenced by the pH of the soil. Soil with a higher pH is more alkaline, and soil with a lower pH is more acidic. Soil with a pH of 6.0-6.2 will produce pink blooms, while soil with a pH of 5.2-5.5 will produce blue blooms.
It’s not the acid itself that turns flowers blue. Rather, acidic soil enables hydrangeas to more readily take up aluminum in the soil.
Foundations and sidewalks both leach lime into the soil, turning the soil more alkaline, which is why hydrangeas in foundation plantings that were blue when they came home from the nursery will soon turn pink.
Lorraine recommends getting a soil test to determine both the pH and any nutrient deficiencies before blindly adding solid amendments or fertilizer to raise or lower pH. Holly-tone, for instance, may make the soil more acidic and the blooms more blue, but it also contains many nutrients that the hydrangeas don’t need.
Only mophead and lacecap hydrangeas change colors. White hydrangeas and hydrangeas in any other shape will not change bloom color, no matter the pH. One new color-changing variety of note is Mathilda Gutges, a mophead bigleaf hydrangea that is deep purple rather than blue in acidic soil.
Hydrangeas as Gift Plants
Small potted hydrangeas have become popular plants to pick up at the store for an easy gift. However, if they are placed outside, they may quickly die in the cold. These are intended for enjoyment indoors, where the blooms can last for months.
If planted outside in warmer weather, these gift plants may survive but never bloom. That’s because they have been bred specifically as indoor plants and cared for under very controlled circumstances to make enticing blooms that encourage shoppers to take them home. Outdoors, they will simply be a green bush, Lorraine says.
Shopping for Hydrangea Care Supplies
Last year, garden centers sold out of many items as so many people took up gardening for the first time. Lorraine’s advice is to get out early this spring to shop for supplies while they last, and get enough for the whole year.
Either shrub fertilizer or rose food is good to keep on hand for all hydrangeas, but especially rebloomers. To be prepared to treat leaf spot diseases and powdery mildew when they came around in July, buy organic treatments now.
And pick up a sharpener for your pruners, because a dull pruner will do more harm than good. Lorraine says to check out YouTube to learn how to sharpen tools — and it’s easier than you think.
Yellow sticky traps will help identify the bugs that have been eating plants, and, last but not least, get plenty of deer repellent.
The Importance of Organic Care Methods for Hydrangeas
Hydrangeas attract pollinators. Lacecap varieties in particular are bee and butterfly magnets. That makes it incredibly important to refrain from spraying hydrangeas with chemical pesticides. Organic, targeted pest treatments are always a better choice than broad-spectrum treatments that will kill off beneficial insects.
Big box stores often don’t carry the organic products that independent garden centers do. That’s one of the reasons why it’s so important to support these small businesses that support us.
If you haven’t already listened to my conversation with Lorraine Ballato on hydrangea care, you can do so now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title.
What is your favorite variety of hydrangea? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
joegardener Online Gardening Academy™: Three popular courses on gardening fundamentals; managing pests, diseases & weeds; and seed starting.
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
“Success with Hydrangeas: A Gardener’s Guide” by Lorraine Ballato
Disclosure: Some product links in this guide are affiliate links, which means we would get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us. None of the items included in this list have any bearing on any compensation being an influencing factor on their inclusion here. The selection of all items featured in this post and podcast were based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Rain Bird, Corona Tools, Milorganite, Soil3, Exmark, Greenhouse Megastore, High Mowing Organic Seeds, and Wild Alaskan Seafood Box. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.