SLC
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Location: Central Connecticut

Only 1 seedling germinated - when do you remove the heat mat

Hello, I started a 16-cell tray of seeds on a heat mat. Only one seedling germinated...it's been a couple of days but no more yet. Everything I find says to remove right away from the heat mat once the seeds have germinated, but I've only got one.

How long should I leave the tray on the heat mat? I still need 15 seeds to germinate....

Any help would be greatly appreciated! Thanks!

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

What kind of seeds? Tomatoes might be Ok to remove but peppers might be really iffy.

Option is to cut them apart in manageable groups.

imafan26
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Location: Hawaii, zone 12a 587 ft elev.

I know many people like to start seeds individually in plugs, but it wastes space for me. I never get all the plugs to germinate and I have a harder time watering since they are easily overwatered and yet can dry out really fast.

Always make sure your seeds are fresh and have been properly stored away from light, heat, and moisture. If you are using older seeds it may still be o.k. (dill and bean soeeds were good for 10 years). Do a germination test if seeds are questionable.

Most of the time when I do use community pots to germinate seeds since they take up much less space and I transplant them to individual pots later. Even in community pots, temperature and light has to be just right or seeds will not germinate. Seeds don't like it too cold or too hot and most seeds will dampen off if the soil is too wet.

Try Applestar's paper towel germination method, it works fairly well, if you have the patience and skill to transplant tiny seedlings.

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applestar
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Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Thanks @imafan :D ...it really does work for me — sometimes too well in that I start too many seeds, then run out of energy and time to transplant them all within the best time frame. :roll:

Just one little detail -- I use sand-sized DE (diatomaceous earth ultrasorb) or vermiculite. I can’t get the roots out of the paper towels and end up breaking them, even when I try to cut apart the paper towel, I tried other kinds of papers — paper napkin, toilet paper, copy paper — but I like these two best. They are easiest to maintain while waiting for seeds to germinate, and roots will slide out of these materials even when overgrown as long as they are soaking wet.

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rainbowgardener
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A couple days is not very long. It won't hurt your one that is germinated to stay on the heat mat a little longer, in fact they grow faster that way. Just be sure it stays watered. On a heat mat, the little bit of soil in those cells dries out out rapidly. I do bottom watering - the cells sit in a tray and I just put a little water in the bottom of the tray, just enough to touch the bottom of the cells. But on a heat mat I may have to do that twice a day. If the soil dries out totally, the little seedling dies.



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