Bigger is better especially if you are going to leave them outside in winter. I know some people get away with leaving the northern highbush outdoors in pots in pretty cold weather. But it would make me very nervous well before it dropped to zero.

In the smaller pots I have to prune often or they get too big and need watering more than once a day in summer heat.

I'm in a much milder climate (we rarely see temps below 20), so I have no trouble overwintering potted northern highbush plants without protection in 7-10 gallon pots. Your climate, though, is another matter. Larger pots would definitely be a good idea (I'd go even larger than 15 gallons if I didn't have to move them), but I'd also be very selective about which varieties I chose. My guess is that you'd have the best chance of success with lowbush, dwarf, and half-high varieties, most of which are hardy to zone 3.

One other suggestion -- I added some more cold-sensitive rabbiteye and southern highbush varieties last year, so, just to be safe, I overwintered them under a frost blanket that I draped over a small greenhouse frame. Even if you don't want to move your pots, you could use PVC pipes/conduit to make a mini hoop house of sorts over each or over a group of pots.

This post was edited by shazaam on Fri, Apr 19, 13 at 11:02

Thanks to all. Here are a few of the details: I am planting all northern high bush varieties (rubel, patriot and ka-bluey), all good to zone 3 or 4. Even though we are typically zone 5, our dry winter winds can make for tough conditions for plants.

This "project" came about because some construction at out place has opened up a new area for potential parking. However our septic tank is right in the middle of that area. So I figured that some planters would keep car traffic off the tank, and allow me to grow blueberries up here (well maybe).

I would prefer that the planters not have to be moved in the winter. So picking an eventual size that is big enough so that they can winter in place outdoors is important. I had been thinking of some 15 gal tree pots, but maybe a 1/2 whiskey barrel would be more appropriate a size. To an extent, I don't need an answer for a bit, as I expect I will be growing the blueberries in some 2gal pots for the first year. But it would be nice to know what size container I eventually will need.

I live in Northern Ohio, zone 5. I am NOT an expert, but I'm trying to learn. I've been growing blueberries in pots for only 3 to 4 years. Given my lack of experience, I'm lucky they are still alive. But except that the plants are a little thinner than I expect, they seem to do reasonably well. Mine are in 14 gallon rubbermaid roughneck storage boxes with a few drain holes drilled in the bottom. (Gardners on another forum recommended them as affordable, but hold up to the elements better than similar storage boxes.). When filled with potting mix, it's too heavy for me to lift. But I can put a rope around it and drag it. For winter, I bury the pots in leaves to insulate the roots. I cover them as needed in the spring with plastic to protect from frost, but I'm not sure that really helps much without adding heat. I cover them with bird net as soon as the berries have a hint of blue or the birds would take them all. I built a simple frame to drape the plastic and the bird net over because the net snags badly and would rip the berries off.

Duke, Blue Crop, and Chandler seem to survive, at least in the short run.

Fruitnut is highly successful growing blueberries and other fruits in pots. He's in Texas and growing in a green house, so clearly he's in a different environment. But I've learned a lot from his posts. It might help to search though some of his old posts.

With proper potting soil (acidic)....growing blueberries in pots is fun and easy. If you start out too small (5 gal)...you will have to re-pot next year. Read Dave Wilson Nursery website for great info.

Lots of info on YouTube about growing blues in pots. I had reasonably good success for many years in containers including half whiskey barrels.

Good luck,

RM

Hey Steve,
I'm have been struggling to grow blueberries here in The Denver area for the last 4 years. The two big hurdles I have found so far are the drying winter winds and the hard water.
The wind was easy, I just wrap with burlap. The hard water I have not found a solution for yet. I don't want to acidulate the water using synthetic fertilizer, and couldn't easily if I wanted to with it coming from the lawn sprinklers.
I have been told that more than high ph blueberries really hate too much calcium and it is calcium that makes our water hard. So giving them the moisture they want is slowly killing them.
This year to try to improve things I'm adding a top dressing of greensand. It should both provide iron, which the Ca is depriving them of and add magnesium which helps reduce the Ca issue. If that is not enough, I will try Epsom salt to bring up the Mg.

I'll be interested to hear what works for you.

Andy

FWIW I did try potted blueberries a few years ago. I learned a few things that might be helpful. The large pots are definitely needed. I did not have large enough pots; I was going to plant them but never did. The leaves took on a reddish tint that I could not identify. They were potted in potting soil and B.O.S.S., sold by O'Toole. I was not able to maintain a consistent moisture level with the small pots and they did not flourish as they should have. I ended up trading them for seeds.

My oldest son is getting his doctorate at Mines in chemical engineering so I had him look over a recent post regarding acidifying water for blueberries. He recommended I take the advice by bamboo_rabbit and use battery acidified water to water them.

So on the advice of others here I purchased 2 Sunshine Blue Southern Highbush that are supposedly hardy to zone 5 but tolerate less acidic soil. They arrived just in time for the spring blizzards and are already looking shabby. I'm bringing them in and out and I can't wait to get them planted.

My goal was to amened the soil as much as possible and rely on the acidified water for them. I'm also going to try some lingonberries the same way. (The things one dreams up in the dead of winter!)

Hopefully I can make it work this time. My BYO is on sabbatical this year as the spring freezes have pretty much done in everything. I should have enough time to get my system down for my blueberries.

Keep us posted on your progress.

Here is a link that might be useful: Blueberry watering - mix vinegar or lemon peel to acidify water

Thanks.

Here's the link to the CSU article on container blueberries:

They seem to prefer a soil which is 40% peat moss, 40% ground coir, 20% perlite. I am giving it a try and we'll see how it works.

It's clear that the 2g containers I am putting the bare root plants in are only a temporary measure. However I will probably hold off on the final container size. Seems like I will need at least a 15g pot, maybe bigger.

I have some litmus test strips, and found that when mixing the soil originally it tested between pH 5 to 5.5. I also tested my water (which is moderately hard) and it needs 1/2t of vinegar per quart to bring it to a pH of 5.0. Since I have plenty of vinegar around I will use that for now. We will see how it goes.

Curious if folks who have been growing northern high bush blueberries can say when they typically leaf out, and how frost/freeze tolerant their leaves are.

Here is a link that might be useful: CSU Container Blueberries

Northern Highbush start to grow leaves when the temperatures have been in the 50's(Fahrenheit) for awhile.Where I live,once things start warming up,it usually doesn't go back to freezing,40's yes and the leaves then can get reddish until the heat comes again. Brady

Acidified water not always necessary, peat moss and ammonium sulfate will often be all that is necessary to control PH. I never acidify my well water and yet my soil ph is on the low side.

RM

Steve,

I'm in zone 6a and my northern highbush plants are leafed out now and have been for maybe three weeks. The leaves are not full size yet and are still developing but the plants do have a good number of leaves.

RM

My blueberries have not leafed out yet, though the buds are swelling. They don't seen to have taken much damage during last month (unlike just about everything else) as temps have seesawed between 60s and single digits. I'll know better in a month.

Andy