How to Overwinter Hydrangeas in Pots: A Complete Guide

THE GROWING ZONE/CONTAINER FORMULA

The growing zone/container formula is first up, assuming your container is frost and/or freeze proof. Your containerized plant doesn’t have the insulating benefit of soil so you need to compensate for that. If the hardiness rating for your plant matches your growing zone, you need to either bring it in or seriously insulate it. Generally speaking, the difference between growing zones and plants needs to be at least 2 zones. For example, if you garden in zone 5, your containerized plant needs to be rated hardy to at least zone 3. Keep in mind that when it comes to H. macrophyllas, stem hardiness (where the flower buds reside) is not always the same as root hardiness (what is stated for plant survival).

Many gardeners grow their Confetti™ panicle hydrangea in a container. This fabulous dwarf hydrangea is hardy to zone 4 so if you garden in zone 6 or warmer, you could get away with keeping it outside (assuming your container can handle the winter temps). But if you have a Hydrangea macrophylla Akadama®, be aware that it is only hardy to zone 6. You better be gardening in zone 8 or warmer to be able to leave it outside for the winter.

LET’S BRING YOUR CONTAINERIZED HYDRANGEAS IN

So, let’s talk about “bringing it in.” An attached unheated garage or basement can work fine. Not so for unheated sheds or other outbuildings. But wait, you can’t bring it in quite yet.

HOW TO OVERWINTER HYDRANGEAS IN CONTAINERS | GARDENADDICTZ

FAQ

What should I do with my potted hydrangea in the winter?

Bring potted hydrangeas inside. Potted hydrangeas overwinter best in a garage or basement where the temperature stays cool but doesn’t freeze.Oct 15, 2024

Can hydrangeas grow in pots permanently?

• Container Size:

  Choose a pot that is at least 16-24 inches wide and deep to accommodate a good-sized hydrangea for a few years. 

• Drainage:

  Ensure the pot has good drainage holes to prevent waterlogging, which can harm the roots. 

• Soil:

  Use a well-draining potting mix, not garden soil, as it can compact and hold too much water. 

• Watering:

  Hydrangeas in pots need regular watering, especially during hot weather, as they can dry out quickly. 

• Sunlight:

  Provide adequate sunlight, as hydrangeas need at least partial shade, depending on the variety. 

• Overwintering:

  If you live in a colder climate, you may need to move the pot indoors or provide extra protection during the winter months. 

• Signs of needing a larger pot:

  If the plant starts to slow down noticeably, flower less, or put on less height and width than normal, it’s time to transplant. 

• Species to consider:

  Some hydrangeas, like Hydrangea macrophylla and Hydrangea paniculata, are particularly well-suited for container growing. 

Should I cut down my hydrangea for winter?

• Why not prune in fall/winter?

  Pruning hydrangeas that bloom on old wood in the fall or winter can remove the flower buds for next year’s blooms. 

• What to do instead?

  • Leave the flower heads: The old flower heads can add winter interest to your garden and also act as a protective layer for the buds. 

  • Prune after flowering: If you need to prune, do so after the flowers have faded in late summer or early spring, depending on the hydrangea variety. 

  • Focus on deadheading: You can remove spent flower heads (deadheading) to tidy up the plant, but avoid cutting back the stems. 

• Hydrangeas that bloom on new wood:

  If you have hydrangeas that bloom on new wood (like panicle hydrangeas), you can prune them in late winter or early spring. 

• General tips:

  • Clean up fall garden: Clear out excess organic matter from your garden in late fall. 

  • Water before frost: Water your hydrangeas before the first frost. 

  • Mulch: Add a thick layer of mulch around the base of the plants for winter protection. 

  • Protect in colder climates: In colder climates, consider wrapping the plants with winter protection. 

How cold can potted hydrangeas tolerate?

• Cold Tolerance:

  Hydrangeas are generally hardy plants, but their cold tolerance varies depending on the species and variety. 

• Short-Term Cold:

  Potted hydrangeas can withstand short periods of cold, even down to around 20°F (-6.6°C). 

• Long-Term Cold:

  However, prolonged exposure to temperatures below 20°F can cause damage, especially to the buds and stems of hydrangeas that bloom on old wood. 

• Protection:

  If you live in an area with cold winters, you may need to protect your potted hydrangeas by moving them to a cooler, unheated location like a garage or basement, or by wrapping the pots in burlap or other insulating materials. 

• Watering:

  Even during dormancy, hydrangeas still need some water, so check the soil moisture and water as needed, about once a month. 

• Blooming:

  If the stems or buds die over the winter, the roots will send up new stems in spring, but the plant won’t flower. 

• Endless Summer Hydrangeas:

  Hydrangeas like Endless Summer bloom on both new and old growth, so even if the growth in the early spring looks dead, they’ll bud out again and will bloom. 

• Smooth and Panicle Hydrangeas:

  Smooth and panicle hydrangeas are hardy all the way down to Zone 3, so they fare well in cold winter temperatures. 

• Other Tips:

  • Choose a protected spot for your container-grown hydrangea, such as a north- or east-facing site where winter temperatures remain somewhat constant. 

  • Hydrangeas do not like heat, so if you live in a warmer region, potted hydrangeas could benefit from some shade in the afternoon to keep the soil wet. 

  • Make sure your container will withstand the rigors of winter. 

How do you overwinter a potted Hydrangea?

‘You should cut away the old wood at the plant’s base and remove any dead or weak branches. Ideally, cut them at the base,’ says gardening and plant expert, Petar Ivanov from Fantastic Gardeners. After that, there are a number of ways to overwinter your potted hydrangea. 1. Move the plant to a basement or a garage

Should I care for my potted Hydrangea over winter?

Properly caring for your potted hydrangea over winter will determine how successful the blooms are in the following summer, and how many you get. The key to this is to protect your plants against the first frost of winter.

Can hydrangeas grow in pots in winter?

Water any pots that feel dry so roots don’t desiccate over winter. Getting pots ready before cold weather allows plants to harden off and enter dormancy stress-free. Hydrangeas in pots thrive over winter in an unheated, protected location with: Temperatures between 32-55°F. Low light. High humidity. Minimal watering.

Can You overwinter hydrangeas indoors?

Overwintering these types of hydrangeas indoors is difficult and usually not successful. Here are a few ways to overwinter your plants. Sink the pot in the ground, if it is an all weather non-decorative container, to protect the roots from the cold. Or move them into an unheated garage once the plants are dormant.

Can hydrangeas survive winter?

Continue watering until the ground freezes. Make sure your container will withstand the rigors of winter. If not you may want to move the plants to a nursery pot that can be placed inside the decorative pot during the growing season. Overwintering these types of hydrangeas indoors is difficult and usually not successful.

How does Hydrangea Winter care work?

Here’s how it works. Proper hydrangea winter care will determine the success and quantity of next summer’s blooms. The key to hydrangea winter protection is to protect your plant, whether in a pot or in the ground, prior to the first frost of winter through the last frost the following spring.