What Temperature Should I Cover My Hydrangeas?

by | Last updated on January 24, 2024

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Hydrangeas, unlike some winter flowers, require protection only in areas where temperatures drop below zero degrees Fahrenheit , says Wilkerson Mill Gardens, but late-spring cold snaps can damage hydrangeas in almost any climate.

What temperature is too cold for hydrangeas?

Effectively, a hydrangea should be able to sustain a temperature of minus-10 degrees . But in the real world, temperatures as low as 12 degrees — and late fall or early spring freezes — may reduce the flowering capability of this hydrangea.

At what temperature do hydrangeas need to be covered?

If these are the species in your garden, you don’t have to worry about winter kill on hydrangea. They don’t need protection unless the temperature dips below negative 30 degrees Fahrenheit (-34 C.) .

Do hydrangeas need to be covered for frost?

Whether or not hydrangeas need protection depends on how cold the winter temperatures drop. If the air temperature doesn’t go below 0 degrees (zone 7) there is no need for winter protection . In colder climates, wrap or completely cover marginally hardy hydrangeas.

How cold tolerant are hydrangeas?

Tolerance to cold and frost varies among hydrangeas. Some hydrangea varieties are cold hardy down to negative 20 degrees Fahrenheit (-30 °C) , others like the popular Bigleaf variety are especially vulnerable to frost damage.

Can hydrangeas survive a hard freeze?

A few nights at or slightly below 32 degrees Fahrenheit are unlikely to kill a hydrangea or do serious long-term damage. Hydrangeas that bloom on old wood are root hardy down to USDA zones 5 and 6, or minus 20 F to minus 15 F. New-wood bloomers are more cold tolerant, down to zones 3 or minus 40 F.

Should hydrangeas be cut back for winter?

Hydrangeas bloom either on old wood or new wood, depending on the hydrangea type. New-wood blooming hydrangeas should be cut back in late winter before new growth begins , while old-wood bloomers require pruning right after flowers fade in late summer.

Do hydrangeas like sun or shade?

The most important factors when choosing where to plant hydrangeas are light and moisture. In the South, plant them where they will receive morning sunlight and afternoon shade . With these conditions, you can grow the extremely popular French (also called bigleaf) hydrangea or panicle hydrangea.

What happens if you don’t prune your hydrangeas?

Hydrangeas that bloom on old wood do not need pruning and are better off for it. If you leave them alone, they’ll bloom more profusely the next season. ... Just remember new growth may come, but that new growth will be without blooms next season.

Do I need to cover my hydrangeas tonight?

Mulching for Cold-Weather Hydrangea Care

Although bare soil absorbs heat faster, it also allows heat to escape faster. For best results, leave the soil bare during the day to absorb heat from the sun and cover the ground in the evening .

Will hydrangeas come back after a freeze?

Even though it can be a big setback, your Hydrangea can almost always recover from damage caused by cold and frost . To treat damaged Hydrangeas, wait until the temperature has warmed up and prune back the affected growth. Your Hydrangea may still bloom this year and should be back to usual growing habits next spring.

Should I cover newly planted hydrangeas?

The best hydrangea winter protection for potted plants is to bring them inside prior to the first frost. If they are too cumbersome to move, they can remain outside and be protected by covering the entire pot and plant. One method is to use foam insulation to protect your potted plants.

How do you prepare a hydrangea for winter?

  1. Prune away the dead branches. ...
  2. Build a frame around your hydrangea plant with stakes of wood. ...
  3. Wrap chicken wire around the frame that you built. ...
  4. Fill the cage with mulch, pine needles or leaves.

Should you prune hydrangeas?

The best advice for hydrangeas is to consider their mature size. Locate them in an area they won’t outgrow and require heavy pruning to keep them in bounds. Hydrangeas do not require strict reqular pruning ; simply keep them healthy by removing dead wood and they will grow and flower well.

Is it too cold to plant hydrangeas?

So, when is the best time to plant hydrangeas? Aim for late spring , well after any danger of frost has passed, or early fall, when night temperatures usher in cooler air. If you garden in a region where the ground freezes, get plants into the ground at least six weeks prior to fall’s first killing frost.

Do hydrangeas grow back after cutting?

Pruning New-Wood Bloomers

You can take a more relaxed attitude about pruning if you have hydrangeas that set flower buds on current season wood, like panicle and smooth hydrangeas. ... Even if you cut canes back to ground level during dormancy, the shrubs will grow back and produce blooms in spring .

David Martineau
Author
David Martineau
David is an interior designer and home improvement expert. With a degree in architecture, David has worked on various renovation projects and has written for several home and garden publications. David's expertise in decorating, renovation, and repair will help you create your dream home.