Reptilian heating pad for germination

[Logolight]

O.K.  After getting everyone's ideas on using bottom heat for germination I came up with a possible solution.  I found a heating pad for reptiles that you can get at Pet Smart.  But here's the question.  I'm using 20 qt. airtight Sterilite containers with about 5 inches of 50/50 Pete/Perlite and the heating pad generates heat at a constant 43C.  Is this temp going to be too warm for the seeds or will it even generate enough heat to warm the 5 inches of medium?  What do you think?

Thanks.

Dave

[Kamipalms]

Dave,

With 5 inches of medium your heat mat will go into overload trying to heat that depth.

Heat mats/cables are designed to be thermostatically controlled , in other words, the heat mat/cables cycle on and off to keep a constant temp. if you run it without a thermostat it won't last too long and the top inch or so of your 5 inches of medium would be lucky to see 20C and if the seeds do germinate in this temp their roots will be cooked by the time they reach the bottom few inches of the medium.

I would strongly suggest you invest in a thermostat.

Something like this: THERMOSTAT

I use a depth of 2 to 2.5 inches to germinate in and heat to 28 to 30C.

I'll get a few pics for you.

Jason.

[Logolight]

Thanks Jason.  I'd like to see those pics you have.  The reason why I used that much medium was to allow for long term growth of the seedlings before I transplant them.  The problem is just getting the seeds warm enough to germinate and I seem to be on the losing end of this issue.  I can see your point about the pad.  The question is does the pad warm up to 43C only or does it warm up hot to maintain 43C of an area.  I'll head to the store and find out and keep you posted.

Thanks again.

Dave.

[Matt in SD]

Wow, now this is weird.  I actually just logged on with the intention of posting about the use of reptile heating pads for seed germination.  I set one up two days ago and put a ~1quart tupperware full of water (about 3 1/2" deep water) on it for 24 hours and it stabilized at 88F (~30C), which seems about perfect.  I'm sure there are different brands and the one I was using was only about 6" by 10".  So maybe the larger ones get hotter (or maybe it's because ours is several years old).

How big is your reptile heat pad?  How much are they at Petco, I figured they'd be cheaper than the propagation mats.

Matt

[Mike4284m]

(Kamipalms @ Sep. 27 2006,09:01)

QUOTE

Dave,

With 5 inches of medium your heat mat will go into overload trying to heat that depth.

Heat mats/cables are designed to be thermostatically controlled , in other words, the heat mat/cables cycle on and off to keep a constant temp. if you run it without a thermostat it won't last too long and the top inch or so of your 5 inches of medium would be lucky to see 20C and if the seeds do germinate in this temp their roots will be cooked by the time they reach the bottom few inches of the medium.

I would strongly suggest you invest in a thermostat.

Something like this: THERMOSTAT

I use a depth of 2 to 2.5 inches to germinate in and heat to 28 to 30C.

I'll get a few pics for you.

Jason.

Actually most of the cheaper heat pads for reptiles do not cycle on or off.  They are usually just a coil covered with a flexible heat resistant plastic.  I believe the temperature they are rated for on the packaging is supposed to be the ambient temperature of the area just above the mat.  I would be hesistant to go by this temperature however and would definately suggest recording some temps before you use it for seeds.

I have never attempted to grow any palms from seed but I do know a bit about the mats themselves.  Good luck.

[Logolight]

Matt, I was looking at different sizes with prices ranging from $16.00 to $45.00.  The name of the heating pads are called Heat Wave and they don't have thermostats.  The directions on the back of the package specify to only use on glass surfaces but my Sterilite containets are plastic so I'm back to square one trying to figure out how to warm those containers.  Here's a pic of the heating pads from Petsmart.com.

[Neofolis]

David, like you, I potted my seeds in a deep medium to allow maximum growth before transplanting, but unfortunately you can't very easily do this with bottom heat, because the heat will not disperse through the medium well.  It will radiate better through some media than others and higher moisture levels help the heat spread more evenly, but it is still not spread evenly enough.  20°C would be enough for some cooler climate seeds to germinate, but most species would want 25-30°C.  You either have the choice of using shallow containers with bottom heat or, if you want to use deeper containers, you will have to create ambient heat.  I prefer the ambient heat approach, because it is a closer synthesis of a natural environment.

[Kamipalms]

(Mike4284m @ Sep. 28 2006,02:15)

QUOTE

(Kamipalms @ Sep. 27 2006,09:01)

QUOTE

Dave,

With 5 inches of medium your heat mat will go into overload trying to heat that depth.

Heat mats/cables are designed to be thermostatically controlled , in other words, the heat mat/cables cycle on and off to keep a constant temp. if you run it without a thermostat it won't last too long and the top inch or so of your 5 inches of medium would be lucky to see 20C and if the seeds do germinate in this temp their roots will be cooked by the time they reach the bottom few inches of the medium.

I would strongly suggest you invest in a thermostat.

Something like this: THERMOSTAT

I use a depth of 2 to 2.5 inches to germinate in and heat to 28 to 30C.

I'll get a few pics for you.

Jason.

Actually most of the cheaper heat pads for reptiles do not cycle on or off.  They are usually just a coil covered with a flexible heat resistant plastic.  I believe the temperature they are rated for on the packaging is supposed to be the ambient temperature of the area just above the mat.  I would be hesistant to go by this temperature however and would definately suggest recording some temps before you use it for seeds.

I have never attempted to grow any palms from seed but I do know a bit about the mats themselves.  Good luck.

Obviously there are many different types of heating mats on the market... more than I knew about but then again, I grow palms not reptiles ???

Heres my setup;

Heat mat is 1m square and controlld by a plug in thermostat. You can just make out the thermostat probe going into the bottle of water , laying flat with the red lid to the left hand side. I've found water holds a more stable temp. The thermostat is set at 25C which in turn heats the medium in the large containers to pretty well spot on 30C. The 2  containers with the blue and creamish lids are 25 litre with 2-2.5 inches of medium in the bottom and thats it.

[MattyB]

Do like Corey suggested.  Put the whole set up in some sort of large box.  That way you can heat the bottom of the medium and the air around it for equal temperature all around the seeds.  I've used tool boxes and two drawers stacked on top of each other.  This works for quite a few containers.  Jason obviously has more than can fit in a box so he has to leave them on a shelf with a thermostat heating the bottoms.

[Neofolis]

That may work although heat mats tend to heat things through contact and I'm not sure the air would heat up that much.  Obviously the heat would eventually disperse to some extent into the confines of the box, but if the temperature outside the box is much lower, the heat would be lost as quickly as it is gained.  You would still have the problem that the very bottom of the soil would be much warmer than anywhere else, so if the seeds did germinate the pot/container would have to be removed from the heat before the roots went too deep.

[MattyB]

Obviously the heat would eventually disperse to some extent into the confines of the box, but if the temperature outside the box is much lower, the heat would be lost as quickly as it is gained.

Your right about this, but it can be combatted by using a thicker walled, or insulated box.  This is why I switched from a thin, plastic walled toolbox, to a thicker particle board walled box.  This winter I'll wrap the whole thing in some insulating material.  This way you can use a lower heat and it's more constant and effective.  Also, if the box is placed indoors, or an area that isn't exposed to the cold then you won't have to worry about the temp loss.  Mine is in my detached garage w/ no heat, so insulation is necessary for me.

[Logolight]

How about a small greenhouse to help lock in the heat.  Here's one I found from a greenhouse website.

[Neofolis]

Those greenhouses will get hot on a sunny day, but won't really retain a great deal of heat at night.  It would probably only be 1-2° warmer inside than out.

An insulated box will help greatly assuming none of the seeds require light to germinate.

[palmazon]

Logo - look on craigslist for anyone getting rid of a waterbed &/or waterbed heater; pm me for details once you've accomplished that

[Matt in SD]

Well, shortly after these posts, I actually set up a germination/seedling overwintering "tank" using a reptile heating pad and a thermostat that is also made for reptile cages.  I took an old fish tank (~40 gallon short tank) and stuck the largest model reptile heater to the bottom of it (they come with adhesive so you can attach them to glass).  I then put masonry sand on the bottom of the tank about 1/2" (1cm) deep, and then put some coco-peat on top of that.  Wetted everything down with good distilled water (the coco-peat helps insulate and also humidify the whole tank), the wet sand distributes the heat from the heat pad.  I put seeds in tupperwares (with coco-peat inside) directly on the sand and then surrounded them with the coco-peat (I figured the coco-peat surrounding the containers would help insulate and normalize temperatures).  And finally put the thermostat probe in a container (the lid can still seal over the cord) and plugged the heating pad into the thermostat, set to ~90F (30C).  The tank is currently covered with a couple sheets of plastic wrap, but I'm going to get a glass or plexiglass sheet and a fluorescent light fixture at some point.

What I'm hoping this will achieve is both a good place to germinate seeds (in the sealed containers) as well as a nice warm, humid environment to get the seedlings through their first couple leaves, particularly in winter time.  Once germinated, I can put the seeds in small pots (i.e. not sealed) on top of the coco-peat so the bottom heat is not so intense, and they can get some light.

So far, so good.  I already have germinated some Ravenea albicans, and Dypsis thiryana seeds in there, as well as a bunch of mystery dicot tree seeds my father-in-law sent me from Zambia.

I'll update if there are any major successes or if something awful happens.

Matt

[Logolight]

Matt, good job there.  Post some pics if you will.  I'm guessing you put the thermostat in one of the containers with the seeds in it and not in a container on it's own.  Also what is the heating pad sitting on below the tank?

[Matt in SD]

I'll try to get a pic posted one of these days.  But until I've had it a bit longer I wouldn't want everyone to go out an copy my "design".  It's definitely not proven.  I'm really curious how the seedlings do in there over the winter (with almost no ventilation)...I'm hoping they'll at least do better than in my unheated greenhouse.

To answer your questions, the thermostat probe is in a container with seeds, sitting on top of the media.  The heating pad is stuck to the glass of the tank.  I propped the tank up on some old CD cases to give a little more space above the tabletop (they can mark up a surface over time).

Matt

[MattyB]

Matt and Others: how do you keep seeds that sit in a sealed container for a long time on bottom heat from rotting?  I'm trying to be super sterile and apply Daconil and I still rot stuff.  I'm thinking that the sealed container is very condusive to rotting stuff.  Still learning.....

[Matt in SD]

Matt,

I haven't been using bottom heat for too long, but I have used sealed containers quite a bit.  I've had some stuff rot, but it's not a major problem.  Definitely had seeds for 6 months or more that don't rot.  For me the biggest thing is to clean and bleach the seeds before putting them in.  I also have found that coco-peat gives me the least fungus problems.  If I see mold on the seeds I'll either spray Daconil or soak the seeds in Daconil or both.  Some seeds (like Geonoma) seem way more prone to rotting than others.

Matt

[MattyB]

I've started using pure perlite to combat the rotting.  It seems like you can get it quite wet and it's still super airy.  I was sterilizing a peat/perlite mix and rotting was still happening.  Where do you get cocopeat?

[Matt in SD]

I get my cocopeat from Hansen/A1soils.  It's $6 for a 3 cu ft bag.  I've grown palm seedlings in the straight cocopeat and they do OK (not an ideal mix but it works), so they seem to do a pretty good job of "desalting" it.

Matt

[Logolight]

Actually I've found that the Perlite is what's been causing the fungus in my containers.  Someone mentioned using distilled water to help inhibit fungus growth so I think I'll try that next time.  I think the best thing to do is transplant the seedlings within a few weeks after they germinate.  I have 4 Wodyetias in about 6 inches of medium.  The roots have hit the bottom of the container and are moving sideways now but the seedlings themselves are still only about two inches high.  I'll most likely be transplanting them in a few weeks before the roots tangle or start to rot.

But like Matt says, always give your seeds a bleach bath before sowing them.  I use a 10/90 bleach/water ratio for one minute then rinse the seeds.

Good luck.