Here is professional guidance on how to put hydrangeas to bed for the winter season from guest bloggers Megan Nichols and Jessie Jacobson of Tonkadale Greenhouse in Minnetonka, Minnesota. (They may have more hydrangea trees and shrubs in their zip code than almost anywhere else in the United States, so they are aware!)
The temperature has dropped, and autumnal symbols can be seen everywhere. The garden needs to be put to bed soon. Hydrangeas reward us with large, stunning, and prodigious blooms all season long. You may say that they are givers. It’s time to return the favour now. It’s time to tuck the hydrangeas in with kisses and wishes for sweaty dreams.
Here in Minnesota, our moods can fluctuate as drastically as the unpredictably harsh winter weather extremes, snowfall, and freeze/thaw cycles. Despite the fact that many hydrangeas are regarded as hardy, all of this can confuse them. To survive the winter and come back bigger and better the next year, they require some care. Although hydrangeas cultivated in warmer areas don’t need as much post-season primping as those grown in our zone, there isn’t a single thing that wouldn’t appreciate a little tender loving care right now.
Utilize these suggestions to get the most out of your hydrangeas so that you can be the one to present at this time next season!
(Is pruning in order? No and yes. Here is our recommendation for which hydrangeas should be pruned right away and which should wait until spring.)
Don’t Stop Watering
Make a commitment! I shall water my hydrangeas till the earth freezes solid, you declare while raising your right hand. really good Hydrangeas are thirsty plants by nature, so it’s essential to give them regular, deep watering. We don’t need to get all linguistically nerdy right now, but their name literally means “hydration.” Winter’s cool, dry winds completely drain the moisture from the vegetation, and hydrangeas don’t use lip balm. It need not be heated in order to be dry!
If a freeze is not a concern where you live, water deeply but sparingly during the winter depending on how much rain you get.
This is how: Making a small hole in the side of a 5-gallon bucket, filling it with water, and placing it at the base of the plant while it slowly drips out of the bucket is one method. Another option is to lay your hose at the base of the plant for about an hour with the water turned on to a gentle drip.
Give Them One Last Hearty Meal
Composting your hydrangea beds in the fall will give them a boost for the upcoming growing season. Everyone feels better after a full night’s sleep and a filling breakfast. This also applies to hydrangeas. After a lengthy winter’s hibernation, they will be ravenous for some nice compost. Compost can decompose during the winter if it is used now, making nutrients easily accessible in spring. A few inches of compost is advisable even in regions without a deep cold. Only compost is being discussed here! Don’t give your hydrangeas fertilisers that are high in nitrogen because this can encourage them to produce new foliage growth.
This is how: Before laying down mulch in colder climates, top dress the area with compost, well-aged manure, or other organic material after the ground has frozen. This organic fertiliser, which is rich in nutrients, will decompose over the winter, making nutrients available to the plant in the spring. Apply compost in the late fall or early winter in zones that are warmer.
Mulch Matters
Mulching helps keep moisture in and weeds out in warmer climates while shielding the crown and roots of your hydrangeas from harsh winter temperatures in colder climates. Snow serves as a natural insulator if everything goes as it should. Plants suffer during strange winters with little snowfall and extreme temperature changes. Apply a thick layer of mulch around the plant’s base to offer hydrangeas the best chance of flourishing. While decorative mulch is useful, straw, marsh hay, or dead leaves are suggested instead.
This is how: Apply a 6–8 layer of mulch once the ground has frozen (or late fall or early winter in zones with milder winters). This shields plants from the heave-ho of springtime freeze/thaw cycles, which can yank them out of the ground. Inviting mice to make this their snug winter home, causing rotting and illness, or tricking the plant into believing it’s time to bud, are all consequences of mulching too early. Be patient; you don’t have to do things early simply because your neighbours are.
Keep Them Cozy
The amount of winter cold determines whether or not hydrangeas require protection. Winter protection is not required in zone 7 if the air temperature stays above zero degrees. Wrap or totally cover barely hardy hydrangeas in chilly areas. This is crucial for plants that bloom on old wood, such hydrangeas with mop heads and large leaves (Hydrangea macrophylla). The most recent types of mop head/big leaf hydrangeas, however, bloom on both fresh and old wood, so it’s important to keep that in mind. In their favour and ours! Hardier hydrangea varieties like the paniculata and arborescens don’t often require additional winter care, although really low temperatures might cause its limbs to die back. Consider covering if a colder than usual winter is forecast.
This is how: Wrap plants loosely in a few layers of burlap, making sure to tie it off with strong twine. Making a mulch mountain and covering the majority of the plant is an additional choice. Smaller, newly planted specimens respond well to this technique.
There’s Still Time To Plant!
The first three varieties of hydrangeas can be grown here in Zone 4; oak leaf hydrangeas can also be grown in warmer climates (zones 5 to 9). The optimal time to plant shrubs is in the fall. Just make sure to do all of the aforementioned things, including watering and mulching.
Here are some of our favourites that you can plant now for stunning blooms the following spring.
Panicle Hydrangeas
These late blooming hydrangeas, sometimes known as PeeGee hydrangeas (summer into early fall). They are covered in elongated, conical flower heads that emerge white or green and blush into pinks and peaches as the season goes on.
How hot should I keep my hydrangeas covered?
When to Take Off the Cover. The following day, when it is at least 50 degrees Fahrenheit, remove the cover.
Can hydrangeas harm frozen ground?
A frost caused harm to my hydrangea. On the stalks, whatever leaves that were present were impacted and perished. I reduced all woody stems to the ground. At the plant’s base, green leaves are forming. I’m hoping the bush makes a comeback. Does it have any potential for growth and will it blossom this year? Garfield Heights’ Linda E.
I hope your hydrangea is now lush and bursting with blooms. Yes, a lot of hydrangeas started to leaf out early this year before being severely impacted by frost, which destroyed their leaves and stems. Fortunately, these plants can withstand being trimmed back to the ground in many cases. My damaged ones were overflowing with lovely flowers despite not having been trimmed down.
It’s a reasonable question to ask whether or not your hydrangea will blossom, and the answer mostly depends on the species.
White-bloomed, 3-foot-tall Hydrangea arborescens, an Ohio native, frequently has stronger stems and more blooms after being severely pruned back to the ground in late winter. “Annabelle,” “Incrediball,” and “Invincibelle Spirit” are some of its cultivars.
Hybrids of H. paniculata, commonly known as “panicle” or “Pee Gee” hydrangeas, can also be hard-cut in the late winter and will bloom on new growth. Given that Pee Gee hydrangeas typically grow to be 8 to 12 feet tall and broad at maturity, I highly doubt you’ve trimmed one of these plants all the way to the ground. They are beautiful and hardy shrubs that can benefit from a late winter pruning to promote blossoms and aid in the development of a full, strong habit. Or just leave them alone.
Pruning is rarely necessary for oakleaf hydrangeas (Hydrangea quercifolia). This plant won’t bloom this year if it is severely pruned, but it will probably live and look lovely the next year.
It is most likely Hydrangea macrophylla if yours has pink or blue flowers. These lacecap or mophead hydrangeas typically only bloom on aged wood. There won’t be any blossoms if the plant is trimmed back too severely or to the ground in late winter. Or if, as is sometimes the case in Northeast Ohio, the cold during a harsh winter killed off the stems and flower buds, there will be few or no blossoms. This is why magnificent displays of pink or blue hydrangeas may only appear in Ohio every three years.
For protection over the winter, wrap them in burlap or cover them with 1 1/2 inches of mulch. If you choose to prune them in the early spring, make sure to leave at least three sets of buds.
Fortunately, some new Hydrangea macrophylla varieties are being developed that bloom on fresh wood as well, which is great news for cold-climate gardeners! These continue to bloom throughout the most of the summer even after being cut (or frozen) to the ground. To promote new growth and flowers, prune them sparingly early in the growing season.
Reblooming cultivars like “Endless Summer,” “Penny Mac,” or the “Let’s Dance” series should be on your radar. Although any hydrangea can have its blooms removed in the fall, pruning them at this time of year is not advised.
During this time of year, the main garden chores are watering, weeding, and cleaning up. Many perennials can be revived by being pruned almost to the ground if they are genuinely looking terrible. When it’s hot and dry outside, water your plants thoroughly a few times per week.
Peonies, poppies, and bearded iris should all be planted between now and mid-September.
Transplant or divide perennials with spring and summer blooms when the days begin to cool. To provide time for plants to grow before winter, try to finish this by early September. Late in the summer, when I divide plants, I usually chop down the foliage by half and water thoroughly. Select days that are expected to be cloudy, rainy, or cool.
Houseplants in pots should be pruned, divided, and replanted right away to give them time to regenerate before being brought back inside.
For drying, gather flowers and herbs. Cut back tomato plants. Harvest and compost any spent produce that cannot be used in the kitchen. Prepare bare regions for transplanting or reseeding.
For fall colour, plant garden chrysanthemums, sternbergia, colchicum bulbs, and autumn crocus. The time to order spring bulbs is now.
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What does frost damage to hydrangeas look like?
Frost-damaged foliage will turn purple or scarlet. It might wilt or crumble. Stems, buds, and leaves may turn black and appear dry after a freeze. It should be clear that this is the issue if you’ve had a frost or unexpected late freeze after your hydrangea have sprouted fresh new growth.
Are hydrangeas often hardy?
Are hydrangeas a perennial plant? If not, how would you know which ones are or are not?
All hydrangeas are perennials that are either woody or herbaceous. Not all hydrangeas are winter resistant, and those that are cannot withstand the cold winters of Zone 5 that can reach -20 degrees, which is an issue for northern locations like Michigan. Those bigleaf hydrangeas (Hydrangea macrophylla) with gorgeous pink and blue, big lacecaps seem to be what we crave. Except in particularly well-sited locations, they struggle in Zone 5. The plants become more widespread and productive as you move further south, into Zone 6 and beyond. These hydrangeas ought to be viewed as container plants in Zone 5 and brought indoors for the winter.
There is a climbing hydrangea (H. petiolaris) that can be utilised to conceal a huge structure or act as a shrub because it is winter-hardy in this area. It develops a white, fragrant blooming in late June that blooms for at least two weeks. The panicle hydrangea (H. paniculata) and oakleaf hydrangea are two more hydrangeas with a big shrub or spreading tree habit (H. quercifolia). Both are effective in a bigger landscape and are winter-resistant. In order to ensure that plant qualities meet your expectations, it is crucial to choose a designated variety from a respected nursery in both situations.
How can plants be protected against frost?
Planting too early might result in a crisis if a cold snap is impending, whether it was because you were seduced by some striking hue at the garden centre or simply wanted to start the gardening season early. It’s not difficult to help your seedlings survive the great frost, but it does take some planning.
When temperatures drop, you can usually rely on improvised protection for plants. The necessary tools must be prepared in advance to protect plants from frigid mornings for larger plantings, such as a food garden.
Knowing when prized vegetation starts to turn frost-burned brown will help you know what to do when freeze warnings are in effect. As a general rule, plants typically freeze when the temperature stays at 28°F for five hours.
There are, of course, exceptions to this rule. When temps drop to 32–33F, seedlings often die because of their delicate new leaves. There are many low-temperature thresholds for tropical plants. Some collapse at temperatures below 40°F, while others break down at 35°F. Other plants are naturally resistant and can endure temperatures as low as 18 to 20 degrees Fahrenheit. Do a search in gardening books and internet resources to discover the threshold for your plants.
Take it up
Moving plants away from potential danger is the simplest cold-protection strategy. Potted plants and seedlings in flats both benefit from this. Moving plants onto a porch with a roof, into a garage or shed, or under a deck frequently provides sufficient shelter.
Rely on Water
Just before sunset, water the soil to raise the temperature of the surrounding air overnight as the water evaporates. Water-filled buckets or gallon jugs should be left in the sun all day. Move them close to threatened plants at night. Air temperatures will be moderated by the water, and if it freezes, heat will be released. To boost midday heating, paint a few water-holding containers black for best results.
the air flowing
The biggest harm is done to plants by cold, motionless air. To prevent frost from accumulating on plants, you can use an electric fan all night to create a breeze. Never forget to keep electrical connections dry.
Plants Should Be CoveredPlants should be covered with sheets, towels, blankets, cardboard, or a tarp to protect them from everything but the harshest freezing (28F for five hours). Inverting baskets, coolers, or any other container with a firm bottom over plants is also an option. Before it gets dark, cover plants to keep warm air in. Coverings shouldn’t ideally contact the foliage. If windy conditions are anticipated, anchor cloth coverings.
When the temperature rises and the frost has melted in the morning, remove coverings. Under dense covers, heat from the sun can accumulate and cause plant death.
Blankets that collapse
Row covers, or gardening blankets, should always be accessible. These covers are created in various thicknesses from plastic or synthetic fibres. Lay row covers directly on the plants, or suspend them over a bed with pegs to form a tunnel.
Activate lights
An incandescent light bulb produces enough heat to raise the temperature of the air around it just enough to keep a plant from freezing. For this method to operate, bulbs must be close to plants (within a distance of 2-3 feet). (Fluorescent bulbs can’t produce enough heat to complete this task.)
Defend specific plants
Set up hot caps
At planting time, stiff plastic containers with venting holes are placed over the individual seedlings. Hot caps function similarly to cloches (small greenhouses), but the daily task of applying and removing the covering is eliminated by venting holes. Use plastic two-liter bottles or gallon jugs with the bottoms cut off and the lids removed to simulate a hot cap (but saved). In the evenings when the weather turns chilly, replace the lids.
A Wall O’Water tepee, which encircles individual plants with a sleeve of water-filled tubes, is a variation on the hot cap concept. During the day, the water absorbs the heat of the sun. The water gently freezes at night, releasing the sun’s stored radiant heat and preventing the air within the tepee from becoming frosty.