The heat

[Green Acre Aquaponics]

So far our experience with the heat has not been a particularly pleasant one.  It seemed to have jump completely over spring here in Florida and gone right to summer.  Our friends in Colorado just had snow and we just had 90's. 

 

Through March, the heat wasn't too bad and although the lettuces looked a little wilty in the afternoon, it didn't seem to be too bad.  Then the first week after our commercial training we had 4 days of clouds and rain.  By the fifth day when the sun came out, so did the heat.  This was on a Friday and we not only were supposed to be at our local farmers market the next day but had a tour too that Saturday.   Not knowing if our crops would recover from the heat that afternoon, we canceled our market spot but proceeded with the tour.  That next morning, everything looked normal and full.  The tour began at 11am and I had no sooner started talking and telling eveyone about the wilting from the heat, that the plants seemed to wilt as we watched them.  Again most everything in the greenhouse but the tomato, watermelon and peas were limp and flat in the afternoon heat with the thermometer reading 111 in the plant area of the greenhouse with 0% humidity.  It was horribly hot and the greenhouse needed some much better ventilation.  The next morning, we planned to cut several large 2' x 5' vents/ holes in the top of the greenhouse film.  That Sunday we cut several holes and added in some small box fans.  It dropped the temp about 5 degrees, but coming down from 111, that wasn't near enough. 

We were now waiting on the large piece of 22.5% shade cloth we had ordered.  This one would go inside the greenhouse on cables so we could slide it open or closed as needed.  It took about a day to install and cost about $50 for the cables(clothesline) and hardware.  It dropped the temps another 8 degrees.  We also discovered that by misting the inside of the greenhouse with the water hose, we could lower the temp another 12 to 15 degrees.  Instead of 106 degrees, we were now getting 85 degrees with 52% humidity from the combination of the additional vents, shadecloth and manual hose misting.   Without introducing some moisture, the humidity was usually 0% at the hottest part of the day and was definately contributing to the wilting.  We will be installing a high pressure misting system for a fraction of the cost hopefully next week.

 

The other things we are doing to deal with the heat is to plant heat tolerant varieties of lettuce and other heat suited crops.  The next 500 feet of trough we are installing will also be cooled.  Here we will grow primarily lettuce and greens that we can not grow in the regular greenhouse.   

 

 

[David Hart]

I'm cheering for you ladies :-)  It will be a challange, in a few months, when our morning low will be 90 (sigh)

Looking forward to any tips you can share....my buddy and I are getting ready to move into a 70' x 160'  green house.

[Green Acre Aquaponics]

Hi Wes, we are hoping to maintain in the high 80's, low 90's.  I think we will be able to maintain that with current shading, fans and misters, except maybe in July and August.  We haven't constucted the misting system so have nothing to report there yet. 

[wes]

What temp range are you aiming for with the greenhouse??? Would love some info on your new misting system, My greenhouse is getting way to hot already also.

[David Waite]

Farm tek sells a greenhouse paint that is for heat control that might help. I use a 30 percent shade cloth on the outside over my greenhouse and it keeps my at 90 in the summer with fans a blasting. I am looking at  a misting system as well. Your system is great. Keep up the great work ladies............D

[David Owens]

Good luck with the Heat. Here in Michigan we had a 70 degree day where we received lots of rain, a small tornado warning and 1.5" hail??? The weather sure is changing!

[wes]

Dont know if it is any help at this point but going forward might be something to consider. I purchased this for my way smaller greenhouse 20' by 11' it is a white greenhouse film blocks 55% of the light thus reducing the heat issue and it diffuses the light all around so you dont get any dark areas in the greenhouse. You can read up on the details if interested at the below link. It is working great so far for us this year I still have to see how it performs in the winter months.

http://www.greenhousemegastore.com/product/white-greenhouse-film-6m...

[Green Acre Aquaponics]

The original covering is a woven greenhouse film from FarmTek, basically their upgraded product.  It has an 8% shade factor and is supposed to have a life of 12 years.  It was part of the greenhouse kit we purchased.

[wes]

Yes the heat here in Fla killer. I was just wondering what type of material you used for the orginal covering. What are the specs on its greenhouse use????Opacity??? Uv rating??? ect?

[David Hart]

  We've been running 8 to 10 degrees over our 'norm' for this time of the year.

It's 6 am and we are at 68 with 100% himidity....when it's 'really summer', it'll be around 90 in the morning, plus the humidity