We have had a very warm winter here in Colorado. I have some container trees (plums and plumcots) in a shed that are starting to have flower buds swelling. I’m afraid they have already hit their chill hour requirement. Searching this site and using Chat, I am not finding any hopeful info. For reference, we usually see plums flowering in April. Any ideas for how to delay bloom, or nurse them to a very early crop? The shed isn’t dark, but they only get a little indirect light. I have kept them on the dry side, water-wise.
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I think it is hard to stop it when it starts and I don’t know of any sprays or such, but maybe others do.
If you happen to have a window in the shed and have power you could try using a coolbot. This is a controller that turns a basic window unit AC into cooling unit for a DIY walk-in cooler.
If you don’t have one around, used window unit ACs can be had pretty cheap or even free. If you have it around there either freecycle or a Buy-Nothing facebook group is worth a shot. Or maybe a wanted ad in a neighborhood or other local email list.
The coolbot is not cheap, so you’d have to decide if it is worth it in the long run. If I had a lot of trees I was trying to keep from waking up too early it might be worth it instead of sweating it out hoping not to lose the whole crop. You’d only have to run it when it was going to be warm, so I don’t think the cost for electricity would be too bad. I doubt the shed is insulated so it won’t be as efficient, but outside temps aren’t too high. Probably worth some spray foam to seal any larger air gaps.
Available from the manufactorer, Johnny’s and other places:
These are popular with market gardeners who want to store their harvest but wouldn’t want to spend the money for a big walk-in cooler.
I haven’t tried it, but just a thought if you were looking for a longer term solution to keep the babies safe.
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Thanks for the ideas @zendog. It’s kinda funny, when I decided to try to stretch my zone (5b) with some warmer leaning stone fruit, my concern was avoiding our usual cold snaps (-10F+). Having them stay too warm never crossed my mind!
I don’t think I will make any big investments to change my setup. This winter is way outside the norm here- National Weather Service says 2d warmest December since 1882 (the warmest was 1933) and the average mean temperature of 42 degrees is 11 degrees higher than normal (whatever that means anymore). Last winter the shed worked fine. I had to turn on a heater a few times, but generally temps stayed in the 30s inside with teens to 40s outside.
Guess I won’t be changing my GrowingFruit handle to ColoradoPluots anytime soon.
Absolutely understand not making the investment, especially if you think this year is an anomoly.
My youngest is finishing up a last year at Boulder and we have heard no complaints about super cold mornings this year, but she doesn’t grow any fruit.
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If she’s a skier, you might hear some complaints. It’s very nice most days, though it’s been very windy at times. The main concerns now are wildfires and drought. Anomaly is a good word for this year.
I was in Durango for several years. Hearing about your problem in Loveland boggles my mind!
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I don’t know of any method to delay budding other than keeping them cold. I doubt you can keep your garage cold enough to do it. My theory is that really cutting back on the water could help, just a theory though.
My tactic would be to try and keep the frost off them. Being container trees you can move them in and out of the garage as needed. It’s a lot of work but I do similar with my potted figs every sprint.
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I have had buds swell and the weather to turn back cold. The issue was even though the weather went cold again and never hit a dangerous freeze. The buds exhausted all there sugars by the time normal bloom came they where not viable .
Buds store the sugars for flowering and the roots catch up pumping energy later.
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Two years ago, in an attempt to dwarf mulberry trees, I tied knots in their trunks. Last year, the trees with knots broke dormancy a full month later than the tree I took the cuttings from. On the knotted trees, buds below the knot put on more than a foot of growth before the buds above the knot even began to grow.
This year, to see if I could repeat the delayed bud break, I tied knots in a few trifoliate orange seedlings. I also have other trifoliate orange seedlings that were started at the same time and are apomictic clones, which I am using for comparison. I’m trying the same technique with apple seedlings as well, but I don’t have a true control group to compare against. Here’s a photo of one of the apple seedlings, for anyone wondering what I’m talking about. At the very least, in a couple of decades I’ll have some very interestingly grained apple wood to turn on my lathe.
I realize this probably doesn’t apply to your situation. I’m mentioning it mainly because I found the effect fascinating, and it could potentially be useful in certain situations if it works more broadly.
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You might do as they do for citrus in Florida, but be careful about ice loading as it could break limbs not well braced
Overview
Florida farmers do spray citrus trees with water to prevent freeze damage
, a technique that uses the “latent heat of fusion” to protect crops. By constantly spraying water, a lay
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I have my pawpaw seedlings in an unheated basement, but it’s still in the upper 40s down there right now. I’ve been filling them with snow every other day to keep them moist and the soil temp down.
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