Chilling my greenhouse

I started chill cycle in the greenhouse Oct 25 and have accumulated ~200 Utah hrs so far. By Jan 1 that will be ~1100 hrs. That’s ~18 hrs per day for 50 more days. Here’s how that’s done in an area with 60s/30s outdoors.

The result is high chill, 300 day growing season, no frost (37-95F annual temp range), no weather damage, no animal pests, no wind, hail etc, low pests, and control over climatic parameters one doesn’t have outside.

The last picture is trees planted spring 2014. Fruit was harvested this yr from 90+% of trees although with variable quality due to limited root system and deficit water this past summer. Water application in 2014 was 12.5 inches. That worked great on a few older trees. Water application will probably increase to 16-18 inches going forward due to bigger trees.


Very nice set up Steve. Have you ever let any trees grow beyond the first top support beams?


Using the sheeting for ‘cloud cover?’ is amazing. You have created autumn in your high tunnel. Once again, just amazing! Amazing.

Those rafters, or whatever they’re called, are 8.5ft above soil line. I’ve let the trees reach 1-2ft above that in the past. But it gets hot up that high so won’t do it again. Cooling doesn’t extend much above the top of the evaporative cooling pads and that’s about 7-8ft.

The reflective material helps keep heat above the trees. I think that takes about 10F off high temps this time of yr. I guess it’s obvious that’s only up there during chilling.

Still learning, always learning fruitnut!

I presume everything will still defoliate without frost/freeze? I know my berries always hold their leaves very late in the season after multiple frosts.

Yes leaves will be off everything in about one month. There’s another current post about forced defoliation that touches on that subject in more detail. That discussion prompted my posting this.

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Impressive Fruitnut I’m wondering if you could chill the soil and roots only to meet the requirements. You know how some people use a heat mat to start seedlings or a soaker hose to water just roots? If you could use an alcohol cooling line or something like that to cool the dirt it might save some money. You know the old lp gas servel refrigerators actually would cool like that. You literally lit them. Aquaponics would be really cool with your setup also and then you would have fish to. Very very nice looking setup.

My understanding is the leaf and flower buds need chilling, not the roots. And I like fish but have other things I’m planning to expand into.


Hmmm maybe you could cool them inside a cloche. The victorian error gardeners use cloche’s to protect their lettuce from freezing during winter ( talk about extending the growing season). Here is what a modern lettuce cloche typically looks like
I was thinking a white trash bag wrapped around the fruit tree with an ac hose running in it. The way your doing it now looks great.

The high today in the greenhouse was 50F while outside the high was 62F with dew point of 20F. A dew point of 20F allows effective evaporative cooling. With a low last night of 37F and high 50 I’d give that about 20 Utah hrs.

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This is a really nice setup. Do I understand it correctly that the chill is due to cloth and fans only or is there anything else at work here?

Shade and evaporative cooling. The brown material at the far end of the greenhouse is called a wet wall. Water runs down a paper/cardboard like material and air is drawn through. If the incoming air is dry it’s cooled by about 10-20F thus cooling the greenhouse.

Fruitnut, I am always in awe of your greenhouse. If I ever get out to Texas near you, I would love to stop by and get a tour. Just amazing.

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I’m always up for a tour and talking about fruit.

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I second Hoosier’s statement. @fruitnut’s greenhouse is amazing. Steve better stop sharing all of his incredible success stories, or I’ll show up like a squatter and bum around his place begging for handouts. Steve, your reports always leave me salavating. You are in stonefruit/figs heaven. A paradise of your own design!

Fruitnut, I’ll never forget when you posted the pics of ‘Orange-Red’ apricots. The color and the juice and brix was excellent. I still have not purchased a tree, I’ll beg for scion wood this early spring. Was the apricot just as good this year? It really looks like a juicy type apricot should look and the color is incredible.

Orangered in greenhouse didn’t set this yr. I’m still working on that issue. Did have a good set outside. Some were average and ran around 18 brix. There were a few on one tree that ran as high as 26 brix. Those were as good as an apricot gets. The difference again from what I could tell was the water status of the tree. The highest brix were from a tree on K9 rootstock that’s always seems water stressed.

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Its the most beautiful apricot I have ever seen.