Are your blueberries northern highbush varieties? Make sure you aren't getting a southern bush. I don't water my blueberries in the winter at all. I'm no expert, hopefully someone else will chime in, but I don't see why your bushes wouldn't be able to survive a winter.

I buy them at a plant nursery, so I'm assuming they're not selling me blueberry varieties that won't survive during the winter season. I'll check tomorrow.

One thing I forgot to mention is that the container is made of thin plastic, so maybe the roots freeze and die? But how come the raspberry plants survive without any problem.

The standard rule is you lose 2 zones when you put something in a pot.

There are plenty of things a good nursery will sell you that will survive in the ground, but not in a pot.

Maybe try burying the pot in the ground for the Winter.The snow should provide decent insulation.Leaves or other material could also be built up around them.
There is a guy in SE Washington,where it does get cold,kept his plants in containers and they froze solid and came back fine the next Spring.
I think it's the lack of moisture that's killing them. Brady

My blueberries are in raised beds as are my raspberries. No doubt the roots froze. They came back fine, i expect a huge crop actually. I agree with Brady, they need some water. You are freeze drying the roots. Raspberries are near impossible to kill, so not a fair comparison. They are extremely invasive too!
If at times you cannot get out to water them, then try putting snow in the pot.
The new fabric pots do not bust and breath well. You may be able to keep them outside in these containers.

Plants generally have roots that are much more tender to cold than their tops and pots are well known to be a problem in this regard. You need to either put the pots in soil or insulate your pots in some other way. This is a subject that has been well researched in commercial horticulture so you won't have any trouble getting the info if you search for it.

I did put snow only once this past winter, but I couldn't do it every month due to the amount of snow on the ground.

My only concern with regards to burying the pots in the ground is that water might accumulate and freeze the roots. The temperatures here can get as low as -22ðF (with wind chills of -40ðF). It can go from 68ðF to -4ðF, rain to freeze, within 48 hours. Would that not kill the roots? Or should I try to make some space between the container and the soil underneath the container. Would that be a good idea?

The shed was unheated and the cold temps killed them in the pots, the ground is a lot warmer. You want the ground soil as close as possible to the container if buried.

When you grow plants in pots many of the roots will grow right along the edge of the container. When it gets cold, it doesn't take much to damage these roots. In that kind of cold, you will need to protect your plants and even so I would expect some winter damage to the tips of the branches each year. We got to zero here this past winter and I had a little damage on most of my plants which are now in the ground. If you must grow them in pots, you need to bury them in sawdust, soil, leaves, etc., to protect them. You can definitely do it though. Also some varieties are known to be more winter tolerant, I believe north country, and north blue are both winter tolerant but they are also half high varieties which I don't like very well because the berries are small. I never lost a plant here during winter in pots but we get to zero, not twenty below. Try searching google and YouTube for ideas on how to protect potted plants in winter.

RM

I was going to replace my two blueberry plants today, but I noticed that one of my plants had green buds that are about to open up. There are 17 of them near ground level on green canes. I would say 10% of the plant is alive. Should I cut of all the dead branches and let the plant grow? Or is it not worth it? As long as it is able to grow into a healthy blueberry plant, I'd like to keep it.

Thanks everyone for the help!

I would try to save it, you can still buy more :)

I am trying some blueberries in pots this year and researched. Found a good video on YouTube and says to bury pots in the winter to insulate. You should put gravel in the bottom of the holes so the pots can drain. With all the effort and expense I have put into my blueberry pots I sure don't want them to freeze. Good Luck.

Ghadames,

I live in northern Ohio, zone 5. We had -20F this winter. My potted blueberries are my only fruit that appear likely to yield a normal crop this year.

Possible ideas.
1) Varieties rated hardy to your zone or colder. (Sorry, I don't know your zone.) I grow Duke, Bluecrop, Chandler, and Aurora. They show trivial winter damage.
2) I bury my pots in leaves for the winter. Because the pile of leaves will compress substantially over the winter, I pile the leaves a couple of inches higher than the pots.
3) Pot size. Fruitnut, who is an expert on growing fruits in pots, uses fairly small pots. Clearly, it works well for fruitnut. But fruitnut lives in Texas so his plants don't need to survive a brutal winter. I use 14 gallon rubbermaid rough neck totes with holes drilled in the bottom. I'm not sure, but I'm guessing that the greater soil mass may be helpful for winter survival.

Because they are less hardy, I drag my potted blackberries into an unheated workshop for the winter. The entire pot freezes solid, But the the garden dirt outdoors freezes too. I've read that even dormant plants need water (less than summer), so I never let the soil dry out.

A well draining low ph soil mix is also important. There are lots of good mixes suggested in other threads. But I'm guessing that is not related to your problem.

Another contributor suggested gravel at the bottom. It must work well for them. But if you have a good soil mix, gravel is not needed. Gravel makes the pot heavy and cuts down on the usable soil volume in the pot.

Good luck.

lsoh,

To be clear, you bury your blueberry pots in the ground and then cover them with leaves?

I'm thinking about burying the pots in the ground and covering the plants with burlap or styrofoam cones. Which one would be better? We get many -20F and windy days in winter.

If I use styrofoam cones, I'm assuming that I would have to be careful not to cover entire pot in order not to dry the soil inside the pot and allow some snow to cover the soil?

I am in Zone 5a. I grow a few blueberry cultivars in pots and the pots are two-third to three-quarter burried in the soil and they stay there during the winter and summer. They survive and thrive this way. They performed dismaly in the ground before moving them to the pots. The Bluecrop and Reka varieties perform relatively better than others.

The frost zone is zone 5 is 24 inches for the most part. I would dig holes in the ground a bit deeper and put the pots in and cover with leaves and mulch. I have had more success with this method for potted plants than putting them in the basement for the winter. I actually did this with water lilies and when I dug them out they were just fine.

Ghadames,

-20F is rare for us. But we hit that several times this winter.

Sorry about the confusion. I don't put my pots in the ground. (That would probably be more effective, but I can't do that.) For winter, I drag all my potted plants into a cluster and just bury the cluster in leaves.

I'm guessing that if you bury your pots in the ground, that would be sufficient without covering them. However, maybe a little mulch of pine bark or leaves would be helpful.

Regarding the cones. There are people on this forum that report success over wintering plants in ways that seem to exclude water. So it might work even if the cones excluded all the water. But probably it would be better if the cones allowed some small amount of water. (The plants won't need much water during winter.)

Wish you success.

Must they be in pots? I really think they are best grown in the ground, not to mention only marginally hardy for you as is.

I would rather grow them in raised beds myself. i have them in pots and in raised beds. Both ways seem to work. The ground is easier, but due to various reasons I have both.

Can't I just bring my potted blueberry into my house for the winter?

"Can't I just bring my potted blueberry into my house for the winter?"

Only if you don't heat your house :-) Plants that grow naturally in temperate climates - like blueberries - need a period of winter dormancy that is governed by cold temperatures and short day lengths. These are conditions that are difficult, if not impossible, to replicate indoors, You need some sort of protected area that stays no warmer than around 40F in winter but never gets much below freezing either. And since the plants are dormant, light is not a requirement. An unheated but attached garage, crawl space, root cellar can all work. Or you can just heel the pots into the ground in late fall and they will share the same cold protection as blueberries planted directly into the ground.

At last we agree! Yes, excellent advice. I would add to take them out ASAP in the spring. Temps still need to be cold else premature growth occurs. Also don't let them dry out. usually watering once a month or so is plenty. Not wet, not dry, slightly moist is the ideal. Too wet and the roots cannot breath, too dry, and the roots will die. Much like our mucosal membranes, roots need to stay moist.

Why do you say they look dead? The buds look plump, the branches don't look shriveled or diseased. It looks like there may be some recent growth on them. Are those small leaves browning and dessicating now?

I assume you mean thread. I can't bury 30 gallon pots, I would have to dig down three feet, and three feet in width. Way too much work.

I live in Chicago and we get cold winters. In the city we do a lot of container gardening on balconies. When I want to overwinter a plant I line the inside of the pot first so the root ball is protected. Home Depot or similar stores carry thin pink fiberglass board that’s used for home insulation. It’s cheap and comes in big sheets. Cut down pieces to fit the inside of the pot (if it’s round you’ll have to use strips). Place around the inside wall of the pot. Some people also put stones in there or bubble wrap, and I’ve heard of people lining with bubble wrap or styrofoam instead of insulation board. Whatever you choose, line the pot well and then fill with dirt and plant. When winter hits, move to a protected area. You can also wrap the exterior again with bubble wrap for extra protection.
Follow everyone else’s advice on watering. But lining the pot should go a long way toward protecting your plant in winter months.

So when you first pot your plants, you line them and leave this in year round I'm assuming?

For those difficult freezing situations wrap the pots in high R-value insulation and seal it with cellophane or plastic wrap. It protects your homes and your pipes it should save your roots.

I had potted strawberries, raspberries, and blueberries. I am in zone 7. In late fall I brought them into an unheated but enclosed porch, which seems to remain somewhere between 5-10 degrees above the outside temperatures. I wrapped all pots in bubble wrap and kept them against the house, and watered them lightly once a week on days when temps were above freezing to avoid the roots drying out. Everything looked OK until late winter when we had a deep cold snap and I covered the entire bunch with an old blackout curtain I had available, which served the additional benefit of keeping one of my cats from digging the soil, and kept it that way for probably a month or so until moving them back against the window side of the porch. When I was sure the last night of freezing temps had passed and I put them outside. Everything did well except the blueberry bush, which I'm pretty sure is dead. Looking for some resources, I did see that blueberries need some light, which surprised me since most outside bushes are advised to cover in mulch. I'm not sure but my conclusion is that blueberries do not do well in pots and if I want to try again, need to give them a chance in the ground. Or else i just focus on raspberries and strawberries.