Hi,
With an unusually cold winter our greenhouse isn't good for much except for lettuce...without adding a heater. Until I can figure out an expensive way to warm it at night we needed another solution.
Since our garage has been averaging a 52°F temperature with outside temperatures in the 20's, I decided to place something there. We sat up a table (4'x8') to hold seed starting trays. However, germination requires soil temperatures of 65°F to 75°F. I priced the growing mats and they are very expensive. We would need about $200 worth of them.
I read online that someone had some success using a heated blanket. So we bought one. Before I could get it installed my 16 year-old daughter claimed it as her own...so we bought a second one. We have 6 MIL plastic below and above the blanket...and taped along the edges to keep it dry. We used old fencing material to build a support cage to cover this large area and to hold the plastic sheeting.
Here's a video showing what we have done. These are left over seeds from last year. We hope to starting planting new heirloom seeds this weekend.
http://www.youtube.com/watch?v=8DC2OxYNrEQ
We'll know in about 4 weeks if the heated blank will work.
Regards,
Chuck
Garage winter nursery for seedlings...
- chuck_n_grace
- Barbara Good

- Posts: 182
- Joined: Sat Jan 08, 2011 7:30 am
- Location: South Carolina
Re: Garage winter nursery for seedlings...
Chuck,you've clearly got a talent for improvising,one thing though,what about the light?If youwant to propagate in the garage you may find you need a grow light or two to avoid the seedlings becoming leggy.The green house avoids this prob. but as you say is more expensive to heat.This side of the pond we can buy electric warming cable that runs in a bed of sand(sort of similar in effect to your electric blanket),I've had a set up like this inside the greenhouse, otherwise unheated, and it avoids the need for supplementary light.
- chuck_n_grace
- Barbara Good

- Posts: 182
- Joined: Sat Jan 08, 2011 7:30 am
- Location: South Carolina
Re: Garage winter nursery for seedlings...
Hi,
I wonder if the sand would work with this electric heated blanket? It would ensure that the heat was absorbed by the sand. Presently, any surface of the blanket not covered by a seed tray is exposed to the air...probably a big waste of heat energy.
I've obtained some literature on lighting. I am using fluorescent lighting only...along with sunlight during the day. I need to spend some time researching grow lights...and get one or two as a supplement.
Regards,
Chuck
I wonder if the sand would work with this electric heated blanket? It would ensure that the heat was absorbed by the sand. Presently, any surface of the blanket not covered by a seed tray is exposed to the air...probably a big waste of heat energy.
I've obtained some literature on lighting. I am using fluorescent lighting only...along with sunlight during the day. I need to spend some time researching grow lights...and get one or two as a supplement.
Regards,
Chuck
Re: Garage winter nursery for seedlings...
Chuck,your going to have to do it by trial and error,Will the blanket work if covered in sand? I think your chief prob is going to be the light thing.
Just a thought,on another thread you say you've got access to free pallets.What d'you do with the wooden cubes? Small wood-burners are cheap to buy/not hard to construct,and could be placed in a greenhouse.............
Just a thought,on another thread you say you've got access to free pallets.What d'you do with the wooden cubes? Small wood-burners are cheap to buy/not hard to construct,and could be placed in a greenhouse.............
- chuck_n_grace
- Barbara Good

- Posts: 182
- Joined: Sat Jan 08, 2011 7:30 am
- Location: South Carolina
Re: Garage winter nursery for seedlings...
Hi,
We placed the electric blanket on a large sheet of supported plywood and covered in thick plastic. We placed the cage over the blanket with a sheet of plastic on temp. Added a digital thermometer. I installed a 48" plant light matched with an ordinary flourescent bulb.
Saturday we planted most of our seeds we need for planting around March 15th. The average temp inside the nursery has been 64 degrees F. We were very impressed with how quickly some of these seeds have germinated. Historically we wait about a week.
Here's a way to save money. We cut some plastic milk jugs into 2 1/2" long by 3/4" wide strips...with an arrow tip. We write the plant names on these with a fine tipped marker and place them in the cell packs. Last year we bought those plastic things (about 24 for six dollars). It's not much...but every bit counts.
Regards,
Chuck
We placed the electric blanket on a large sheet of supported plywood and covered in thick plastic. We placed the cage over the blanket with a sheet of plastic on temp. Added a digital thermometer. I installed a 48" plant light matched with an ordinary flourescent bulb.
Saturday we planted most of our seeds we need for planting around March 15th. The average temp inside the nursery has been 64 degrees F. We were very impressed with how quickly some of these seeds have germinated. Historically we wait about a week.
Here's a way to save money. We cut some plastic milk jugs into 2 1/2" long by 3/4" wide strips...with an arrow tip. We write the plant names on these with a fine tipped marker and place them in the cell packs. Last year we bought those plastic things (about 24 for six dollars). It's not much...but every bit counts.
Regards,
Chuck
- chuck_n_grace
- Barbara Good

- Posts: 182
- Joined: Sat Jan 08, 2011 7:30 am
- Location: South Carolina
Re: Garage winter nursery for seedlings...
*Update*
Our home made propagator worked very well. We have nearly 400 seedlings that have germinated quickly. In fact they are a bit 'leggy'. So, we moved them today to our small 8'x8' plastic greenhouse. That should give them a lot more light...hopefully they'll thicken up.
We did buy a second grow light...for some other seeds. I'll probably need to lower the light fixture closer to the plants.
I've placed a small heater in the greenhouse. We'll use it if the temperature is forecasted to go down too low near or below freezing. It would be nice to not use any electricity.
Regards,
Chuck
Our home made propagator worked very well. We have nearly 400 seedlings that have germinated quickly. In fact they are a bit 'leggy'. So, we moved them today to our small 8'x8' plastic greenhouse. That should give them a lot more light...hopefully they'll thicken up.
We did buy a second grow light...for some other seeds. I'll probably need to lower the light fixture closer to the plants.
I've placed a small heater in the greenhouse. We'll use it if the temperature is forecasted to go down too low near or below freezing. It would be nice to not use any electricity.
Regards,
Chuck
