Heat mat

[redser]

Hi, Just wondering if anyones uses a heat mat to grow seedlings? I've found a second hand reptile mat online which looks a good deal. The chap has thermostats and other bits and bobs so I'm hoping to get chatting to someone who uses heat mats and can give me some advise. He thinks it is 12" x 48" but needs to check. Sounds like a nice size to me and could be very handy in the greenhouse in early spring.

Thanks!

[george356]

I was thinking of something similar for our soon to be erected greenhouse. My plan is to construct a box with 5" deep sides, use soil heating cable and a thermostat from Ebay sellers. I will bury the cable in horticultural sand, 2" below the cable and 2" above. I only have to decide on the size

[redser]

Thanks George. I thought about cable too but I just want something more portable instead of having a sand box. A heat mat could be easily rolled up when I'm done with it.

[george356]

A heat mat could be easily rolled up when I'm done with it.

That's true, I hadn't thought of that

[rustylady]

Of course you will need electricity in the greenhouse - have you thought of that?

[redser]

I have indeed. I havn't looked into it in detail yet but the neighbour ran it out to their garden shed last year and said it was straight forward so I have a name of a guy I could use.

[kathyd]

I used a cable this year, buried in sand, like George. It was fantastic to get an early start with tomatoes and peppers and things - mine were twice the size of every else's around here, and started to crop much earlier. However - George - you'll probably find you'll need to cover your seedlings, even in a greenhouse, for a long time after they start to grow, so you may want to think about the height of your box before you start to build it. I was still bubble-wrapping mine at night when they were a good 12-18 inches tall because of the late spring...

[redser]

Thanks Kathy. So it that a permenant setup or do you empty the sand and take the whole thing out of the greenhouse once the season warms up? I would go for a cable as I think it's cheaper, but I had it in my head that it would be a pain to put up/take down. I want to grow in the GH borders so I dont want permenant staging etc.

[kathyd]

It's permanent...It's in the porch, and it's designed to become a big planter trough thing in the summer, and I've sat pots of tomato plants on top of the sand. They were very happy, but I have no idea what state the cable will be in when I move the pots of course . I'm assuming it's designed to cope with damp, and it should be OK. I don't know what happens if you want to top it up with several inches of soil though, plus you'd then have to remove all the soil ready to use the cable again in the spring, which would be even sillier than removing the cable before the summer! I suppose it depends on what you want to plant in your borders - anything in pots or growbags would be OK I'm sure. Could you bury it in the top layer of soil in your beds instead of a separate box maybe? Assuming you wouldn't still be using the cable when you were ready to plant out of course.

[redser]

Thanks kathy, that's an interesting set up I guess I plan to use for part of February, all of march and some of April if its particularly cold. But I would hope to have the plants off eat at this stage. Thanks for the description.

[snakeshack]

I use reptile heatmats under trays when my electric propagator is full,first DON'T roll it up as it damages the mat and is a potential electrical hazard. 12" x 48" is a big mat by reptile standards and under trays without propagator lids will tend to make your compost dry out from the bottom,using a thermostat is optional,OK for a permanent installation but as a temporary propagator to give extra space for seeds in the spring is probably not cost effective,I would also suggest you do not have wet sand/compost in direct contact with the mat esp if second hand,I just stand gravel trays on top of mine then there's no risk of water & electrics getting too friendly with each other,Of course you could just buy a secondhand vivarium (or in my case use a spare) and upgrade the lighting to produce a large thermostatically controlled propagator.

[redser]

Thanks a lot snakeshack, good points there. He has thermostats for a tenner so I think it could be worth it so i can turn up the juice a bit on very cold nights and down then to harden off the plants as spring moves to summer. You say you stand gravel trays on yours. So the heat is strong enough to penetrate the plastic bottom and into the compost, great!
He has a number of thermostats and I dont know which would be best for the heat mat. Here's the link to his advert in case you have the time to take a look
Appreciate it!

Reptile Equipment For Sale in Inchicore, Dublin from yipsntrips

[lottie dolly]

Grow Your Own Magazine - GYO Growing & How To Grow Vegetables tomatoes & fruit from your garden - Tips on Growing

look at this see if it helps out,don't know if the link will work,but you can search it,

[redser]

Brilliant, thanks alot lottie dolly. Searched and found it here ...
http://www.growfruitandveg.co.uk/gra...tor_70817.html

[snakeshack]

the whole point of the thermostat is to maintain the temperature at which you set it."turning up the juice"will increase the temperature at which the stat switches off the mat.below the set temperature the mat is "on".Turning up the stat wont make it get warmer quicker.For veg,the cheapest stat will be adequate as the compost layer will have a buffering effect between on & off cycles.Pulse proportional or dimmer stats will reduce the constant on & off cycling but are assuredly much more expensive.