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HEATING MAT how long to keep it ON?

Irving, TX(Zone 8a)

I have started my tomatoes seeds yesterday. I have a heating mat underneath.
It is working great.

How long to I keep the heating mat on?

All day untill the seeds will sprout?
only during the day?

I just don't want to cook my seeds.

Calgary, Canada

I would use it all day and night until they sprout. Then remove it.

Phoenix, AZ(Zone 9b)

I leave mine on all the time, 24/7. It's a very low heat temp. Also, it's good to place to towel or something under the mat if it's placed on a glass or concrete surface which sucks all the heat down.

I started my broccoli and chinese cabbage sprouts a few weeks ago and they have been on the heat mat the entire time. They are lookin' good! Just moved them outside today. Gotta find time to pot them up.

Coos Bay, OR(Zone 9a)

I used to keep mine in the basement---on 24/7 until sprouted. That worked great. Now my Love has taken over my spot down there with his stuff, so I moved to the GH. Now I have almost 0 success. I thought it was maybe too light, but maybe it just doesn't get enough heat because I have not placed anything under the mat. Don't you just hate when you have to start all over with a system?

Phoenix, AZ(Zone 9b)

beebonnet, That could be the trick alright. What is the shelf made of that the mat sits on? I found that a piece of carpet or a thick towel actually holds too much heat. A thin placemat has turned out to be 'just right'. My seed starting setup is a desk that is topped with a thick piece of glass. It was the glass that sucked all the heat down.

Irving, TX(Zone 8a)

My mat is seating in a piece of wood.
I had to go buy a thermostat because the temperature of the mat was going too high ... i still hope I didn't bake my seeds !!
I am keeping the mat temperature at 80 F degrees.

Phoenix, AZ(Zone 9b)

hmmm, I don't have a thermometer for it, just use my hand. I found that the wood did not suck the heat like the glass or, when they were on the floor, the cement. We topped the desk with a large piece of thick glass so clean up would be easier and water spills etc would not matter.

Coos Bay, OR(Zone 9a)

Wow! All your posts are so informative. My greenhouse has slated wood 2x2's nailed to cross wood pieces so that there is a space between each 2x2. We are talking about an unheated greenhouse. I am now convinced that I need to put something under the rubbery heat mat (mine is very old) to hold in more heat. I think we have a piece of glass about the right size somewhere. After the holidays I am going to check around this place and see what I can come up with....

Phoenix, AZ(Zone 9b)

Did any of you see this post by JoParrott? She is using a string of lights/rope lights as a heating mat. Love the idea!

http://davesgarden.com/community/forums/t/1143980/

Irving, TX(Zone 8a)

I agree, IT IS VERY CLEVER.
Maybe next time ...

Richland, WA(Zone 7b)

Well, thanks for the praise- my rope light is doing a fine job. In the past the heating mats would get too warm, but the rope is a very gentle warmth. I have the 6f t, but it comes in 20 ft at Lowe's in the lighting dep't. (If the garden shops discover it they will market it at twice the price). The 6 ft was only $6.

SE Houston (Hobby), TX(Zone 9a)

Watch all those rope lights disappear at the end of the Christmas season...

Phoenix, AZ(Zone 9b)

ummm, actually no. They are available all year. Those lights are especially useful in lighting outdoor porch steps. We have them strung inside a big, dark 'china cabinet' so we can see what's inside. They're not just for Christmas.

Leesburg, FL(Zone 9b)

I have a neighbor that uses them on top of their cabinets for additional subtle lightening.

SE Houston (Hobby), TX(Zone 9a)

KEWL!

Richland, WA(Zone 7b)

Yes, they are "Kewl"- and cool, too! I am using clear, but the colors would put out heat too, and be decorative- hopefully there will be some on good sales after the holidays-

Calgary, Canada

Are you using the new LED type?

Phoenix, AZ(Zone 9b)

DH just came from that room where he gave the cat food dish a fresh scoop. In addition to being the seed starting room, the cat has claimed it as hers. I removed the starts from the mat and planted them in the garden last week but left the heat mat on. Sure enough, Lily found her way to it. Nice warm spot for an aging feline!

SE Houston (Hobby), TX(Zone 9a)

Thanks, MaryMcP!

Irving, TX(Zone 8a)

MaryMcP it is really a coincidence you wrote about your cat ... just this morning I spot my kitty guarding my seedlings.
In this picture he is checking for germination.

Thumbnail by drthor
Irving, TX(Zone 8a)

But he normally does that ...

Thumbnail by drthor
Phoenix, AZ(Zone 9b)

That's funny drthor.....DH says: "Somebody pour in the lavendar bath salts." Very funny pic. Sometimes, when life is giving me too much stress, I just wanna be one of my pets. :~|

Irving, TX(Zone 8a)

Ahhhhhh
I just found my kitty on TOP of my new seedlings !!! FULL BODY WEIGHT !!!
He must really like the heating mat.
I may need to restart a few pots ... and MUST keep the laundry room door close !!!

Central, TX(Zone 8b)

My advice is to buy a single heat mat for the CAT! I put one in the bottom on a plastic laundry basket covered by a towel for TC (my cat) - he just loves the warmth and his own apartment! Now he leaves seedling shelves alone!!!

If you have a strictly outside cat, enclose same in a larger heavy cardboard box (cut out opening) covered with clear plastic to keep out the moisture and place in a protected spot. Kitty comes and goes but will happily nest in a warm spot overnight. Just be sure to use extension cord rated for outside use.

Jackson, MO(Zone 6b)

I purchased a heat mat last year and had "0" luck. I was really disappointed.
Does anyone have a source to read on how to use a heat mat. It did not come with a "thermostat" and I have no idea what kind of thermostat to use. Where does one purchase a thermostat for a heat mat? I believe my heat mat was too hot. Or, maybe I did not keep the soil moist enough.
How do you keep your soil moist? Do you put something underneath the pots? What kind of pots do you use? Are they the "fiber" ones that can be planted in the soil?

Richland, WA(Zone 7b)

Thermostats for heat mats are pretty expensive. I plan to use rope lights-(just got an 18' long one at BigLots Christmas half price- $3.75.) I now have a 6' one attached to the underside of a wire shelf, and it gives very gentle heat-just right for germination.

Richland, WA(Zone 7b)

This thread shows my light in use. http://davesgarden.com/community/forums/t/1143980/

Central, TX(Zone 8b)

Quote from birder17 :
I purchased a heat mat last year and had "0" luck. I was really disappointed.
Does anyone have a source to read on how to use a heat mat. It did not come with a "thermostat" and I have no idea what kind of thermostat to use. Where does one purchase a thermostat for a heat mat? I believe my heat mat was too hot. Or, maybe I did not keep the soil moist enough.
How do you keep your soil moist? Do you put something underneath the pots? What kind of pots do you use? Are they the "fiber" ones that can be planted in the soil?


See this string: http://davesgarden.com/guides/articles/view/556/

I have good results using a flat sized tray with inserts (various sizes) or as one large seeding tray. Use a quality germinating mix, moistened (like a wrung out sponge), fresh seeds (pre-soaked in warm water with a teaspoon of seaweed), then seeded in the cells or whole flat, covered with plastic wrap or a clear plastic flat cover and placed on the heat mat (yes, I use a thermostat) under grow lights (leave on for 14 hours) until they sprout. Then the cover comes off and I monitor soil moisture, bottom watering as necessary (set flat in a pan of water until the flat surface shows signs of moisture), then draining before placing back on shelf. Once seedlings are up I lower the temperature a little - too much heat isn't good and dry soil means the seeds dry out after they initially take up water (the first step in germination) so they die.

I don't recommend peat pots or peat pellets for anything - they dry out or stay way too wet. I start seeds in community pots, pick out and grow on in paper pots I make myself from newspaper (Google "paper pot maker") using a wooden form or one could use tomato sauce/paste cans as a form.



Jackson, MO(Zone 6b)

Thanks for the good instructions and the article. That helped.
What is a community pot?

Everett, WA(Zone 8a)

I think that drywall ("gypsum") would be a better insulator than wood. Home Depot recently had some small sheets for around $3.50 (3'x3'? Around 3/4" thick).

The biggest heat stealer is air circulation and evaporation. If a mat is on top of slats with gaps, you're heating the whole room as much as the soil. If the soil isn't covered, evaporation cools the soil.

I think that covering the soil with anything (even thin plastic film) will hold much more heat in.

Of courwse, as soon as seeds start sprouting, you want to move the seedlings out from under plastic, and give them air and bright light.

Corey

SE Houston (Hobby), TX(Zone 9a)

Birder17,
A "community pot" is a single container that you've sown all your seeds in versus growing in individual cells of a tray or eggcarton type vessel with separate compartments for each plant...

Phoenix, AZ(Zone 9b)

The piece of drywall as insulator between the heat mat and, say, a glass top, is a good idea. Thanks for mentioning it.

Coos Bay, OR(Zone 9a)

Yes---Drywall. I, too, like that idea. Now, to get some.

Everett, WA(Zone 8a)

For me, the liklihood of trying it went way up when I saw a small sheet of drywall (3'x3'?) at Home Depot. Buying a 4'x8' panel didn't appeal.

On the other hand, when I bought some cedar planks for raised beds, I was told they would cut those for free. Maybe they would cut down a 4x8 panel into 16 1'x2' sheets (if anyone needed that many!).

YMMV.

Corey

Coos Bay, OR(Zone 9a)

Wow!! The cost of things these days is staggering. DH tells me has has saved the cut out for my sink with Formica on top from years ago. He stored it in the pole barn and I didn't even know it. I am going to try that under the heat mat.

Winnipeg, MB(Zone 4a)

[quote="drthor"I spot my kitty guarding my seedlings.
In this picture he is checking for germination.[/quote]

drthor, I luv this picture! I'm enjoying reading everyone's stories!

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