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Spooner, WI

In a 6x8 hoop house how much can it raise ground temp. in a weeks time ?any recamendation in how long and how deep to put them ? Any suggestions on type NW WISCONSIN thanks

3/2/2023 8:45:00 PM

Lodi, California

I'm not going to pretend to be an expert on heating cables, but I do know something about electricity and power, and most heating cables are like, 50 watts, which is a pathetic amount of heat to be putting into even a small area. It's probably more useful in your climate than mine, but I've decided it's not worth it. I get the soil nice and fluffy and full of air, and run a space heater in the greenhouse a week before planting. Gets the soil nice and warm.

I know some people use roof heating ice cables. Those are longer and put out more heat, in addition to being cheaper, but from what I've heard a lot of them have thermostats that only kick in when it freezes, which isn't ideal for this application

3/2/2023 9:38:41 PM

Elk County, PA

These ones have no thermostat. Which means you need to manually check the temperature. Old school meat thermometer stick it the ground leave it there. 300 watt, they will heat you up quickly.
As for depth, if you can get around the 10" depth great, Some places of my garden are more clay then others so I'll dig around 8" then just mound up on top. As for length, I go for 60' because of the cost increase to 80'. If you plan to dig the entire 6 X 8 for a cable You may want to consider larger option. Personally I do 4 x 6 and the 60' does just fine.
https://www.amazon.com/Frost-King-RC60-Watts-Electric/dp/B000PN7HCG/ref=sxts_rp_s_a_1_0?content-id=amzn1.sym.eff26b9b-e255-411b-a40d-eccb21f93fe4%3Aamzn1.sym.eff26b9b-e255-411b-a40d-eccb21f93fe4&crid=1PS2RASM0AFM&cv_ct_cx=frost+king+heat+cable&keywords=frost+king+heat+cable&pd_rd_i=B000PN7HCG&pd_rd_r=3def0b72-b3fe-413c-b83b-c3b1c2d42e61&pd_rd_w=pLVWH&pd_rd_wg=S9o0M&pf_rd_p=eff26b9b-e255-411b-a40d-eccb21f93fe4&pf_rd_r=W3PBMN80SFMZJCVFEKCE&qid=1677811889&sprefix=frost+king+%2Caps%2C95&sr=1-1-5985efba-8948-4f09-9122-d605505c9d1e

3/2/2023 9:59:31 PM

Elk County, PA

http://www.bigpumpkins.com/Diary/DiaryView.asp?season=2015&grower=63916&action=L

Scroll down to his April entries, its where I learned it from. It will give you an idea how quickly they will heat your ground.

3/2/2023 10:02:49 PM

Massachusetts

Wrap-On is one manufacturer of the larger-diameter cables that are used for roof ice and soil heating. They do not have a built-in thermostat. They run continuously or you need a thermostat of your choosing. I bought a couple of cables a few years ago (they still work BTW) and at that time Wrap-On included a chart with their recommendations to "maintain optimum warming temperatures" for soil heating. You have 48SF. Their chart says you need a 120 ft. length cable to cover 43SF. The cable should be covered (buried) with 3-4 inches of soil. I provide this as a reference. Personally, I find it difficult to squeeze 120 ft. of cable into that size structure.

3/3/2023 7:53:29 AM

Massachusetts

The Wrap-On cables draw 5 watts per foot so that is something to think about also. The lights in my entire neighborhood dim when I plug mine in.

3/3/2023 7:57:53 AM

Springfield, VT

The self regulating roof cables work really well. The advantage is they donot get to hot. They will warm soil from mid 40 degrees to about 72 degrees in 24 hours. I;m using 30' tapes in a 5x5 space evenly spaced in a spiral. A timer could be used to provide a crude control, I found I couldn't raise the soil temperature about 86 degrees so leaving them on is not an issue. Timer wise first 24 hours leave on to bring up to temp, Next couple weeks is 12 hours on 12 off. After wards it is about 8 hours on, finishing to about 4 hours on.

3/3/2023 8:27:48 AM

Ohio.. The Good Part

60' gutter heating cables without built in thermostats. The aftermarket thermostats aren't too expensive and work great. I cut a 5'x5' piece of cattle panel and zip tie the cable to it so it's easier to dig up and helps protect the wires.

3/3/2023 5:47:36 PM

Spooner, WI

Thanks for everyone's input

3/3/2023 7:08:37 PM

Deer Park WA

We use 40' gutter heating cables plugged into a cheap digital thermostat with a remote thermister (thermostay. Bury the cables around 10 inches deep. Simple and effective. May go to 60' cables in one planting area to heat a larger area and see if it makes a difference. PS we have used the same cables for 3 years now.

3/3/2023 11:04:00 PM

Spooner, WI

do you leave them in tell after harvest or when ground temps warm enough?

3/4/2023 6:40:32 PM

Ohio.. The Good Part

mine usually stay buried until it's time to turn the garden over the following spring, then checked out and reburied at the new spot this will be year 4.

3/4/2023 7:56:24 PM

Pittsburgh, PA

80’ Wrap-on gutter cables plugged into a heat mat thermometer are ideal. Burried about 10” deep, they can heat my soil into the 70’s in a couple days. I have had issues with them shorting out so I no longer bury the crimped end or the crimp towards the plug.

3/4/2023 10:25:24 PM

Upa Creek, Mo

This is a northern latitude problem as I have never used them, but I always admire the microclimates people create.

I have seen some great pics in old diaries where people are growing in hoops with snow on the outside. Here are a few, so it is doable.

http://bigpumpkins.com/Diary/DiaryViewOne.asp?eid=314060

http://bigpumpkins.com/Diary/DiaryViewOne.asp?eid=302894

http://bigpumpkins.com/Diary/DiaryViewOne.asp?eid=287644

3/5/2023 10:43:30 AM