Germination heat suggestions!

October 29, 2014

I germinate my plants in my shop where the average winter temp is around sixty five degrees F. My tomatoes always germinate and grow well under my fluorescent grow lights, but my pepper plants have always struggled to germinate and grow in the same conditions. This year, I plan to add some additional heat to help the peppers germinate and grow.

I've thought of many different methods. Since I germinate on a raised tray about two inches below the lights and then lower the tray as the plants grow, I've considered using a heat lamp to heat the enclosed space below the tray removing the lamp after germination is complete. I can incorporate a thermostat into the setup to moderate the temp at around eighty degrees. I've also considered simply using heat mats below each germination tray. I haven't really decided what I want to do.

Suggestions will be appreciated along with recommended equipment and vendors who sell it online.

Ted

Lindalana · October 29, 2014

I have radiant heat floors in the bathroom and germinate seeds in plastic baggies on paper towels... I do pre soak them and usually get very uniform germination- soonest about 24 hrs and few days at most... then transplant into cell trays... I do not have much space under lights so when I put trays under lights I want every cell germinated.
Tomatoes need moisture and heat to germinate well so do peppers, I mean sweet ones, bell and non bell.

KarenO · October 29, 2014

Ted,

I think you will have the most reliable results for germination from bottom heat supplied by purpose made seedling heat mats. Covering the seedling trays until germination begins will keep the warmth and moisture in the trays nicely. No need for lights until the first ones germinate, at which time remove any covering and place close to your light source.
KarenO

JamesL · October 29, 2014

What Karen said.
Heat mats for the win. Faster germination times. Better germination rate and consistent early growth. A thermostat is a must though. 10x20 trays with humidity domes are also helpful. I am partial to the Hydrofarm Brand. Consistent product and they make various sizes to accommodate single or multiple trays. They sell them pretty much everywhere online as well as locally at the garden centers, Home Depot and hydro shops.

Worth1 · October 29, 2014

From 75 to 80 degrees.

My house is too cold in the winter to get good results from pepper seeds it gos to 50 at night to 65 in the day even if I have to turn the AC on.

Worth

AlittleSalt · October 29, 2014

Ted, a really good question. I was also wondering if we need to use heat mats here in North Central Texas? I just learned how to start tomatoes from seed this summer, so I've never tried in late February - early April.

greenthumbomaha · October 29, 2014

Ted, I've added a few procedures to get better pepper germination, and had great results last year. I use the same Hydrofarm mats and thermometers as the others, but mine vary in heat output. I have a foam board under the heat mats to direct the heat up into the tray rather than heating the table underneath. If I still need a boost, I cover the each plastic dome with a bath towel. Keeps everything nice and toasty inside and the pepper seeds seem to be much happier than using a heat mat without the goodies. No need to get a bunch of mats as the trays don't stay on that long and you can rotate. That way you won't be rushed to pot up when a million sprout at the same time.

- Lisa

peppero · October 30, 2014

Ted I saw some plans somewhere for a germinating box using a string of christmas tree lights(Not LED) placed in sand which provided an even heat source.. Sand was 1-2 inches deep and I believe aluminum foil was placed on the bottom to reflect heat up. The box was built to dimensions to accomodate the transparent cover which I think was just the clear plastic type used in the type ofgerminating kits sold by walmart and other stores. Of course, you can make the sides of the box tall enough so that could just use clear plastic.

Or, you could just buy a heating mat and miss all of the fun and feeling of personal accomplishment as well as possible frustration.

As I have no personal experience regarding this design(caveat emptor) I can not say how well it works but, I plan to try this idea for the coming germinating season.

Jon

AlittleSalt · November 2, 2014

I read a reply on a different thread about basically the same thing. I'm not going to use a heat mat. I am going to put my seed trays on top of my refrigerator. My fridge is around 6' tall and there is plenty of heat at 6'. My wife stands 5'-0" and often turns the heat up in winter and early spring. I'm 6'-1" and it's hot at 6' when I stand up. I like the idea of using the heat I'm already paying for to keep us warm. Why not use it to start seeds?

About 5-10 years ago, it was popular to be /do things "Green". I guess popularity is something? Using things in a logical way makes sense to me.

November 3, 2014

I bought a couple of the Hydrofarm mats last week. UPS tracking says they will be delivered tomorrow. I am more concerned about burning my seedlings to a crisp with too much heat with the mats than not enough heat. I have some test seeds planted in dry medium to test the mats when they arrive. All I need to do is add a little water, turn the mats on; and sit back and observe. Since I don't need to germinate seed for my garden until mid December, I have plenty of time to experiment and get it right.

Ted

JamesL · November 4, 2014

Ted,
Burning them up is the very reason I would advocate acquiring a thermostat.

Cole_Robbie · November 4, 2014

I use an electric space heater in either a closet or a wooden box I built in the greenhouse. I'm sure I get my seeds hotter than what is recommended, but it's fast and it works. In my experience, drying out is what kills plants or sprouts, which of course is accelerated by high heat, but as long as I keep things moist, everything's fine. I often starts seeds in vermiculite, which is very good at retaining water.

ChristinaJo · November 6, 2014

Last year, I used my spare bedroom. I turned on the electric blanket on low and placed my tomato,pepper, and Eggplant seeds on top(in trays). Seemed to work fine. This year the spare bedroom isn't a spare anymore! So, I'm thinking of using my cheap Big Lots greenhouse and set it up in my garage and the grow lights will be enough heat to sprout. At least, that's the plan I'm toying with.

October 29, 2014	#1
tedln Guest Posts: n/a	Germination heat suggestions! I germinate my plants in my shop where the average winter temp is around sixty five degrees F. My tomatoes always germinate and grow well under my fluorescent grow lights, but my pepper plants have always struggled to germinate and grow in the same conditions. This year, I plan to add some additional heat to help the peppers germinate and grow. I've thought of many different methods. Since I germinate on a raised tray about two inches below the lights and then lower the tray as the plants grow, I've considered using a heat lamp to heat the enclosed space below the tray removing the lamp after germination is complete. I can incorporate a thermostat into the setup to moderate the temp at around eighty degrees. I've also considered simply using heat mats below each germination tray. I haven't really decided what I want to do. Suggestions will be appreciated along with recommended equipment and vendors who sell it online. Ted

October 29, 2014	#6
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	Ted, a really good question. I was also wondering if we need to use heat mats here in North Central Texas? I just learned how to start tomatoes from seed this summer, so I've never tried in late February - early April. Last edited by AlittleSalt; October 29, 2014 at 09:13 PM. Reason: missing word

October 30, 2014	#8
peppero Tomatovillian™ Join Date: Jan 2009 Location: selmer, tn Posts: 2,944	Ted I saw some plans somewhere for a germinating box using a string of christmas tree lights(Not LED) placed in sand which provided an even heat source.. Sand was 1-2 inches deep and I believe aluminum foil was placed on the bottom to reflect heat up. The box was built to dimensions to accomodate the transparent cover which I think was just the clear plastic type used in the type ofgerminating kits sold by walmart and other stores. Of course, you can make the sides of the box tall enough so that could just use clear plastic. Or, you could just buy a heating mat and miss all of the fun and feeling of personal accomplishment as well as possible frustration. As I have no personal experience regarding this design(caveat emptor) I can not say how well it works but, I plan to try this idea for the coming germinating season. Jon Last edited by peppero; October 30, 2014 at 07:05 AM. Reason: added content

October 29, 2014	#2
Lindalana Tomatovillian™ Join Date: Oct 2013 Location: Chicago IL Posts: 857	I have radiant heat floors in the bathroom and germinate seeds in plastic baggies on paper towels... I do pre soak them and usually get very uniform germination- soonest about 24 hrs and few days at most... then transplant into cell trays... I do not have much space under lights so when I put trays under lights I want every cell germinated. Tomatoes need moisture and heat to germinate well so do peppers, I mean sweet ones, bell and non bell.

October 29, 2014	#3
KarenO Tomatovillian™ Join Date: Oct 2012 Location: Vancouver Island Posts: 5,931	Ted, I think you will have the most reliable results for germination from bottom heat supplied by purpose made seedling heat mats. Covering the seedling trays until germination begins will keep the warmth and moisture in the trays nicely. No need for lights until the first ones germinate, at which time remove any covering and place close to your light source. KarenO

October 29, 2014	#4
JamesL Tomatovillian™ Join Date: Nov 2011 Location: Long Island NY Posts: 1,992	What Karen said. Heat mats for the win. Faster germination times. Better germination rate and consistent early growth. A thermostat is a must though. 10x20 trays with humidity domes are also helpful. I am partial to the Hydrofarm Brand. Consistent product and they make various sizes to accommodate single or multiple trays. They sell them pretty much everywhere online as well as locally at the garden centers, Home Depot and hydro shops.

October 29, 2014	#5
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	From 75 to 80 degrees. My house is too cold in the winter to get good results from pepper seeds it gos to 50 at night to 65 in the day even if I have to turn the AC on. Worth

October 29, 2014	#7
greenthumbomaha Tomatovillian™ Join Date: Nov 2011 Location: Omaha Zone 5 Posts: 2,514	Ted, I've added a few procedures to get better pepper germination, and had great results last year. I use the same Hydrofarm mats and thermometers as the others, but mine vary in heat output. I have a foam board under the heat mats to direct the heat up into the tray rather than heating the table underneath. If I still need a boost, I cover the each plastic dome with a bath towel. Keeps everything nice and toasty inside and the pepper seeds seem to be much happier than using a heat mat without the goodies. No need to get a bunch of mats as the trays don't stay on that long and you can rotate. That way you won't be rushed to pot up when a million sprout at the same time. - Lisa

November 2, 2014	#9
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	I read a reply on a different thread about basically the same thing. I'm not going to use a heat mat. I am going to put my seed trays on top of my refrigerator. My fridge is around 6' tall and there is plenty of heat at 6'. My wife stands 5'-0" and often turns the heat up in winter and early spring. I'm 6'-1" and it's hot at 6' when I stand up. I like the idea of using the heat I'm already paying for to keep us warm. Why not use it to start seeds? About 5-10 years ago, it was popular to be /do things "Green". I guess popularity is something? Using things in a logical way makes sense to me.

November 3, 2014	#10
tedln Guest Posts: n/a	I bought a couple of the Hydrofarm mats last week. UPS tracking says they will be delivered tomorrow. I am more concerned about burning my seedlings to a crisp with too much heat with the mats than not enough heat. I have some test seeds planted in dry medium to test the mats when they arrive. All I need to do is add a little water, turn the mats on; and sit back and observe. Since I don't need to germinate seed for my garden until mid December, I have plenty of time to experiment and get it right. Ted

November 4, 2014	#11
JamesL Tomatovillian™ Join Date: Nov 2011 Location: Long Island NY Posts: 1,992	Ted, Burning them up is the very reason I would advocate acquiring a thermostat.

November 4, 2014	#12
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	I use an electric space heater in either a closet or a wooden box I built in the greenhouse. I'm sure I get my seeds hotter than what is recommended, but it's fast and it works. In my experience, drying out is what kills plants or sprouts, which of course is accelerated by high heat, but as long as I keep things moist, everything's fine. I often starts seeds in vermiculite, which is very good at retaining water.

November 6, 2014	#13
ChristinaJo Tomatovillian™ Join Date: Jul 2012 Location: NE Texas Posts: 425	Last year, I used my spare bedroom. I turned on the electric blanket on low and placed my tomato,pepper, and Eggplant seeds on top(in trays). Seemed to work fine. This year the spare bedroom isn't a spare anymore! So, I'm thinking of using my cheap Big Lots greenhouse and set it up in my garage and the grow lights will be enough heat to sprout. At least, that's the plan I'm toying with.