How to protect potted elderberry plants for winter - Ask Extension
I have two elderberry bushes and a blueberry bush that I have had potted since the spring. As we prepare for the colder months how can I protect my sh...
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How to protect potted elderberry plants for winter #920491
Asked October 23, 2025, 11:13 AM EDT
I have two elderberry bushes and a blueberry bush that I have had potted since the spring. As we prepare for the colder months how can I protect my shrubs for next spring? They’re two years old and have been moved to bigger pots on my patio about 2 months ago.
Prince George's County Maryland
Expert Response
If you're not able to plant them in the ground, which will insulate the roots, the next-best approach is to heel them in. Heeling-in is simply planting a potted plant in the ground without taking the pot off, so it's able to be pulled back up and put where you want it for the next growing season. Use a planting depth that puts the entire soil-filled portion of the pot in the ground; that is, you can have the rim sticking up above the soil so it's easier to find and pull back up in spring, but otherwise try to have the surface of the soil in the pot be level with the surface of the surrounding ground. This type of "planting" will help to insulate the root ball, which is very important for helping it survive the winter out of the ground.
Another option is to use bulky material to help insulate the pot from drastic temperature swings. Anything that increases the mass of the root ball can help, such as bags of mulch or soil/compost, or straw bales piled against the sides of the pot. Thinner material like bubble wrap will not provide much insulation.
If neither of those methods is an option, you can pull the pots close to the house wall on the side of the building sheltered from winter winds, which usually come from the northwest.
Regardless of whichever method you try, check on the pots periodically for watering needs, because potting mix dries out faster than in-ground soil. You can also consider using "pot feet," which are short props (ceramic, plastic, brick, etc.) that support the pot about an inch or two off the ground, so water draining from the bottom drain hole(s) doesn't dam-up as ice if the temperature drops, which could then prevent the container from draining fully, potentially suffocating roots. When checking them for water, it's the same technique as used in summer: feel the soil about two or so inches down and water only once the soil has become somewhat dry to the touch at that depth. Elderberry and blueberry shrubs are a bit more tolerant of staying damp than they are drying out, so you have more leeway with accidental over-watering than with under-watering in terms of root stress or dieback. When the pot is frozen, moisture will be unavailable to roots, so try to make sure the containers are checked for watering needs before a predicted freeze.
Miri
Another option is to use bulky material to help insulate the pot from drastic temperature swings. Anything that increases the mass of the root ball can help, such as bags of mulch or soil/compost, or straw bales piled against the sides of the pot. Thinner material like bubble wrap will not provide much insulation.
If neither of those methods is an option, you can pull the pots close to the house wall on the side of the building sheltered from winter winds, which usually come from the northwest.
Regardless of whichever method you try, check on the pots periodically for watering needs, because potting mix dries out faster than in-ground soil. You can also consider using "pot feet," which are short props (ceramic, plastic, brick, etc.) that support the pot about an inch or two off the ground, so water draining from the bottom drain hole(s) doesn't dam-up as ice if the temperature drops, which could then prevent the container from draining fully, potentially suffocating roots. When checking them for water, it's the same technique as used in summer: feel the soil about two or so inches down and water only once the soil has become somewhat dry to the touch at that depth. Elderberry and blueberry shrubs are a bit more tolerant of staying damp than they are drying out, so you have more leeway with accidental over-watering than with under-watering in terms of root stress or dieback. When the pot is frozen, moisture will be unavailable to roots, so try to make sure the containers are checked for watering needs before a predicted freeze.
Miri
Thank you! This is helpful. I am able to plant in ground so I will do so in the upcoming week or so. Is there anything I need to know in particular when transferring to the ground? Also, do I need to water over winter or only until it begins to freeze?
You're welcome.
Nothing different from planting during the spring or summer: loosen any tangled roots well (you probably won't many many or any, due to the recent repotting) and try to keep the plant at the same depth in the ground that is was growing in the pot. (The top of the root ball from the pot should be level with the surrounding soil when it goes into the ground.) Mulch them well without piling mulch against the base of the main stems...a 3-inch thick layer should suffice over the root zone.
Some gardeners check on watering needs all winter (during thaws that allow for probing the soil to check moisture) while others do not. Being newly-installed plants, though, it would help to be check on them occasionally during winter if we have stretches of mild weather and little precipitation. The same method is used as would be done during the growing season: feeling the soil as we described for checking on potted plants, but at a 4- or 6-inch depth rather than just a couple inches.
Miri
Nothing different from planting during the spring or summer: loosen any tangled roots well (you probably won't many many or any, due to the recent repotting) and try to keep the plant at the same depth in the ground that is was growing in the pot. (The top of the root ball from the pot should be level with the surrounding soil when it goes into the ground.) Mulch them well without piling mulch against the base of the main stems...a 3-inch thick layer should suffice over the root zone.
Some gardeners check on watering needs all winter (during thaws that allow for probing the soil to check moisture) while others do not. Being newly-installed plants, though, it would help to be check on them occasionally during winter if we have stretches of mild weather and little precipitation. The same method is used as would be done during the growing season: feeling the soil as we described for checking on potted plants, but at a 4- or 6-inch depth rather than just a couple inches.
Miri
