I'd cut back those bull canes and tip the longer new growth elsewhere. The bull canes are like the one on the upper photo growing off to the right. In my experience those don't branch out down low. All the branches will be up at the top at some point. So I'd cut those back at the point where you want branches.

But I'd not prune back the more mature growth. If you prune the later you might be cutting off most of next years fruit.

Edweather,

I grow a ton of fruit and my favorite is BB. Back in PA had a bunch of bushes now here in Florida have over 40 (Really need to count them one of these days) They range from 2 years up to 9 year old plants.

My take is a bit different from Fruitnuts....first you are in zone 5? You are asking for trouble if you prune those bushes now. You prune and the plant will take it as a sign to make a new flush which will take a couple weeks to initiate and the last thing you want is new tender growth.

Second....I would NOT touch those bull shoots. Fruitnut is correct that they tend not to limb down low but that is a good not a bad thing. Their are a few advantages of having limbs just up high.

1. Snow and ice protection. A load of snow and ice on a cane that has branches just at the top makes the cane arch down toward the ground and that limb is unlikely to snap. Canes with low branches tend to wedge against each other and can snap.

2. High branched canes tend to arch out when laden with fruit which moves them away from their neighbors and maximizes light that reaches the leaves which helps to carry and mature a heavier crop load.

3. High branched canes are easier to pick, less stooping.

4. High branched canes tend to make the plant have a healthier V shape by opening up the middle of the plant to air and sun and that promotes health.

This winter when they are dormant I would remove some of that twiggy lower growth and the branches that cross and touch. Try to move the limb growth outward away from the plants core. Don't remove much as it will hurt the amount of fruit you will get but limiting fruiting on a young plant makes it do more vegetative growth and that is a plus.

They look like nice plants..very well taken care of.

Those plants are in pots. It wouldn't be smart to leave them out in the snow this winter. If you let the bull canes grow until they quit on there own they are going to need support when they set fruit. Supporting them in a pot isn't that easy, I've tried and wished I'd pruned them down lower.

Also there won't be any difference in hardiness of the canes if they are tipped or pruned now. They are already growing. Tipping won't make any significant difference in winter hardiness. And plants in pots in Z5 need to be brought inside during the real cold of winter. Some place like a garage that stays near freezing.

Fruitnut,

While those canes may now be growing they will stop soon, he is in zone 5 after all. If you prune them now the plant will try to make new growth but that process you trigger when you prune will take a couple weeks to even start to swell the new branch buds. So you have at a minimum 2 weeks to initiation then at least a month before that growth will stop no matter what the weather does. Plants do not start or stop on a dime.

If you notice the plants are in pots with a nice railing right behind them, perfect support. They are growing very well and will have to be repotted eventually and that will completely alleviate the pot tipping problem anyway.

Please though tell me what the advantage of pruning them now is instead of waiting until the plant is dormant and pruning them in late winter if he decides they need pruned.

bamboo:

I agree the pruning could just as well be done next spring. In fact you are right it be better done next spring. Water and fertilizer are more important than pruning in determining winter hardiness. So I'd tell him to stop fertilizing and reduce water if hardiness is an issue.

By and large I think those varieties are hardy in Z5 and the plants are pretty good at shutting down as needed. But I've never grown bb in that zone.

The main thing is whether or not those bull shoots should be tipped. For mine in pots I'm going to tip and cause branching down low rather than try to prop up long shoots. I want the flexibility to move the pots at any time. If they weren't moved all summer then tall shoots could be tried off to anything solid.

Here's a picture from April 2011 of a Sweet Crisp in a 5 gallon pot that was tipped but not low enough. The plants were grown rapidly which leads to strong bull shoots. I propped up the shoots with difficulty. Now 5 months later the plant has been potted up to 12 gallons. It was pruned back some after harvest but is still too tall and will need support for spring 2012 crop.

{{gwi:14873}}

The plant in August 2011 after potting up. Kinda hard to see but it's too tall.

{{gwi:122316}}

fruitnut and bamboo rabbit, thanks for the discussion. I really appreciate it. I think I'll hold off on pruning for now, and I'll keep an eye on the height of the bull shoots. Pruning "a little" of the twiggy inner growth later sounds like a good idea.

Even though both plants are winter hardy to -20F to -30F, I am planning to put them in the garage where the winter temperature is between 25F and 40F. How long should I keep fertilizing? Right now I'm fertilizing once per week. I'm already cutting back a little on the watering from every other day to about twice per week. The sun angle is lower, cooler temps, more cloud cover, and more rain. Thanks again.

ed:

I'd stop fertilizing until next spring. There is no need to push more growth at this time. Your winter plans sound ideal.

Guess I'll have to offer another alternative opinion and that's all it is. But I see little or no need to thin the twiggy growth. The plants aren't too thick. The fruit will be on that small wood and any thinning will just reduce your crop. I can't see those plants being overloaded with fruit next year. That's assuming they leaf out nicely.

You have figured out how to make the plants grow, they are charged up with vitality right now, and that vitality will carry over until next spring. This, and some spring fertilizer, will assure plentiful leafing next spring. That's my take anyway.

Anyway good luck with your crop!!

I was going through my draw and found an article about pruning blueberries I'd stashed away from an Oct 2003 issue of Fruitgrower News. In the summary there was a paragraph that might be relevant.

"Remove the low growth that would touch the ground when loaded with fruit. Cut out short, soft, new wood that developed from the base of the plant late in the season."

Generally I would follow the advice of Fruitnut as he has the major experience of container growing. I don't like moving plants in the garage, however. You can also either insulate the pots and mulch the top or set the plants into soil for over wintering. The problem is that garages can get too warm and mess with dormancy and timing for taking plants out can be tricky as the environment can make them tender. If your garage consistently sustains a temp around freezing this may not be a problem. I don't know about blueberries but I've seen lots of trouble with figs kept in garages.

I don't believe that pruning stimulates late growth once terminal buds are set and I also don't believe that if you manage to stimulate such growth it endangers plants- from my observation of fruit trees this is one of those horticultural myths. Late growth itself is tender but the rest of plants seem to harden off normally. This is based on anecdotal observation only but I've yet to see any actual research on the subject so I'll run with that because it's my own. Anyway thought someone might find it interesting. I certainly recommend pruning most plants that you're still trying to get bigger when they're dormant.

Edweather,
Hi. I agree with H-man in regards to overwintering the bb pots in the garage. You'll also have to deal with dessication. I overwintered 350 bluecrops and elliott last spring in Z5b with nice snow cover and up against a wall on the north. I also parked my trailer and my old van on the other sides to slow down the wind. Just make sure they dont dry out in the pots into dormancy and freezing. And, they shouldn't be waterlogged/saturated. Any new growth initiated now wont have time to harden off. Sounds like you're right on track.
Good luck!
Noogy

Ed,

What is your water like there? I am not a fan of daily watering of BB unless you are blessed with a naturally low PH.

Fruitnut,

As a side note.....are those sweet crisps to die for or what? I removed some older gulfcoast and south moon BB just to put in 20 of them I liked the fruit so much. They do have a tendency to grow tall. Last September I went to a local commercial BB farm and bought 20 small bareroot plants. When I put them in the ground I pruned them to balance roots and tops then this spring before bud break pruned them again down to 12". They have grown like weeds with some bull shoots over 5 feet tall already.

Harvestman,

Pruning of BB absolutely stimulates growth if the plant is not dormant no matter what buds are present. I never said it would endanger the plant but what is the sense in promoting growth that will simply be lost due to cold...it is a waste of the plants energy. Here in Florida we prune BB right after harvest as it gains us another extra flush of growth. I do agree on what you said about a garage.... but the temps he states his garage stays at should work no problem.

bamboo:

I've been singing the praises of Sweetcrisp so much on this site that most people think I've slipped over the edge. I think they are the greatest blueberry I've ever tried by far. Sounds like you agree.

Have you ever tried Bluecrisp? It's supposed to be similar to Sweetcrisp. But it's been released for some time and isn't popular. So I'm wondering what's wrong with it.

OK.........so now I'm completely confused. I love it. For now I'm not going to do anything. I probably could find a spot for them and overwinter them outdoors. If I do put them in the garage, I wouldn't be until the garage really cooled off.

b r....My tap water has a pH of about 8. I did several pH experiments with vinegar and 4 different Ph drop test kits, and litmus papers. The tests were a bit subjective, but the results I came up with told me to add an ounce (2 tablespoons) of 5% vinegar per gallon of water. Which, if I remember correctly, brought the pH of the water down to about 4.5. I never watered every day. I watered every other day in the heat of summer because the containers dried out quickly. Now I'm down to twice a week.

Fruitnut,

I do not grow Bluecrisp but have tasted it on a farm up in Gainesville. It was good but not as sweet as sweetcrisp, the flavor had a bit of a acid after taste to me. The texture of the two is about identical. Not sure if you grow Sunshineblue but bluecrisp is a bit like it in that the berries are not sweet until some days after they turn dark blue though not as slow to sweeten as the sunshineblue. Bluecrisp is also more spreading than upright, more so than sweetcrisp and I prefer the more upright growers but that is just aesthetic. Bluecrisp for me would be touch and go on chill hours. Though I do grow 3 rabbiteye BB but they only get a good fruit load some years, others the load is lite due to lack of chill.

Ed,

What you are doing water wise is working as the plants look great. My comments were geared more towards people that grow them in the ground and have more plants where doctoring water would be more of a pain. When do you think you will repot?