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 favor 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 fertilizers 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 fertilizer, 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 neighbors 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 favor 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 favorites 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.
Do I need to protect my hydrangeas from spring frost?
According to Wilkerson Mill Gardens, hydrangeas, unlike some winter flowers, only need protection in regions where the temperature falls below 0 degrees Fahrenheit; nevertheless, late-spring cold spells can harm hydrangeas in practically any environment. Although the plants’ stems and roots can withstand cold temperatures, as their buds start to expand in anticipation of blooming, they are more susceptible to injury. When temperatures are projected to drop below freezing, covering hydrangeas for the winter is as simple as draping a blanket over bigger plants or arranging a box over smaller plants. In order to prevent the plants from overheating under their covering, remove it as soon as the daytime temperatures start to rise.
What degree of heat do hydrangeas require protection from?
One of the simplest shrubs to grow is the hydrangea. Hydrangeas are easy maintenance plants that provide your garden with months of huge, bright flower decoration. However, it’s crucial to understand how to protect hydrangeas from cold as summer ends and winter sneaks up on us. This entails hydrangea cold tolerance. Some types, such as the panicle or PG hydrangea and the smooth hydrangea (“Annabelle”), are extremely cold-hardy and bloom on new wood.
You don’t need to be concerned about hydrangea winter kill if these species are present in your yard. They don’t need to be protected unless it is below minus 30 degrees Fahrenheit (-34 C.). In most cases, protecting these plants also involves leaving the old growth during the winter, which can contribute to the winter’s visual appeal.
The preceding growth season is when all of the other hydrangea kinds, including the well-liked big leaf, produce their flowers. For you to see blooming the following summer, these tender buds must endure the winter. You should find out how to avoid winter kill on hydrangeas if you plan to plant big leaf or another variety that blooms on old wood.
Do hydrangeas get hurt by frost?
One of the most exquisite and many flowers you may have in your garden or landscape is a hydrangea. But they can be suddenly and unexpectedly damaged by cold and frost. Fortunately, there are a few things you can do to assist your hydrangeas regain their former beauty, if not this year then most definitely the following.
Your Hydrangea can nearly always bounce back from damage brought on by cold and frost, despite the fact that it can be a significant setback. Wait till the weather has warmed up before pruning back the harmed growth on damaged hydrangeas. Your hydrangea might still bloom this year and return to its typical growth patterns the following spring.
A hydrangea can be harmed by frost and cold, but happily, these plants are fairly resilient. Frost-damaged hydrangeas will probably recover with a little TLC if pruned properly, even though it might affect this year’s flowers.
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 center 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 fibers. 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.
What degree of temperature causes damage to hydrangea buds?
When nights are clear and cold, at least 32 degrees Fahrenheit, plants suffer from frost damage because they lose more heat through their leaves than they gain, making the plant colder than the surrounding air. Plant cells burst as a result of water inside the plant freezing. When exposed to chilling or slight cold damage, plants turn scarlet.
The leaves and newly budding buds become dark brown to black and wilted with more severe frost damage. Even after a frost or freeze, hydrangeas that haven’t sprung any new growth or formed flower buds are likely to be fine.
Bigleaf hydrangeas are the variety of hydrangea that sustain the most damage because they have a poor dormancy and have a propensity to put out leaves and bloom buds quickly in the first warm weather of the season. For cultivars like these, hydrangea and spring frosts are a danger. According to University of New Hampshire Cooperative Extension, hydrangea frost damage that persists throughout the summer can be quite harmful. According to the University of Massachusetts Amherst, covering hydrangea plants with burlap or mulching them with leaves or straw can help keep them safe over the winter.
How should a hydrangea be wrapped?
Winter damage, according to Clemson University Cooperative Extension, is the main reason why hydrangea blooms fail to open. Don’t stop watering hydrangeas until the ground freezes, advises Tonkadale Nurseries, in order to start hydrangea preparation for the winter. Set a dripping hose next to the plant for about an hour to water it occasionally throughout the winter if the ground doesn’t freeze. Place a few inches of compost (not fertilizer) around the plant in late fall or early winter or after the ground freezes to supply nutrients in the spring. Over the compost, spread 6 to 8 inches of mulch, straw, or fallen leaves.
Wrapping hydrangeas in burlap will shield them from the winter chill and wind chill factor. The National Garden Bureau advises beginning with a tomato cage or chicken wire-based wire structure. Burlap should be wrapped around the wire or cage, and it should be secured with twine. Fill the interior with pine needles, straw, hay, or other filler with care. Bubble wrap can be placed around the cage’s outside for increased insulation, and a cover made of burlap, plastic, or craft foam can be fastened to the top.