Easy & Cheap Homemade Heatbox Seed Germinator

Easy & Cheap Homemade Heatbox Seed Germinator



  • Plastic cooler
  • 50 count strand  Christmas Indoor/Outdoor Christmas Lights or Rope Lights
  • 15×10  pan (I used a jelly roll)
  • Extension cord


  1.  Put the Christmas lights in the bottom of the cooler. Make sure the electrical connection is outside the cooler. I do this because there is A LOT of condensation that forms in the cooler and I didn’t want water on the connection of the extension cord and the light strand connection.  My thinking is the lights themselves can take the condensation since they are indoor/outdoor lights and they are used outside in my SNOW & RAIN weather. I used only 50 light strand and that produced enough heat to stimulate germination.  100 strand lights or larger would be TOO HOT.
  2. Put the pan on top of the lights.  This will prevent water sitting on the lights that has maybe drained from your seedling containers.
  3. Put your cell packs or any other seedling containers on the 15×10 pan.
  4. Close the cover of your cooler.

Most of my seedlings sprouted in a few days.  Of course, some seedlings take longer… like peppers.  I left the lights on DAY & NIGHT.  I did check them daily to see if the condensation was affecting the lights in any way. Everything was fine.  Not only is this a CHEAP & EASY method of germination, my success in starting from seed was the best I have ever done. I found this method of HEAT GERMINATION better than the heat mat because the seeds seemed to stay at a more even moisture.  I know this box doesn’t hold A LOT of seeds , but I don’t need a large amount all at once. After I see that the seeds have germinated, I take them out and put them under grow lights. Then you can put another set of seeds in the HEAT BOX SEED GERMINATOR.

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4 thoughts on “Easy & Cheap Homemade Heatbox Seed Germinator

  1. I happened on your site by chance searching for twig trellis, I am soo glad I did- this is an awesome idea- I have been looking for a germination option -besides expensive grow lights- and love this! Do you have to keep the coolers inside a building or can you leave them outside?

  2. I have not tried the HEATBOX outside, mine is in the basement. Some seeds need light to germinate, so you will still need grow lights or a sunny window. The HEATBOX SEED GERMINATOR is for seeds that need heat and no light to germinate. Today, I took out my Hyacinth Bean Vine from the HEATBOX. Ten out of twelve seeds germinated in a week. Now they are out in the ROLLING SHELF GREENHOUSE soaking up some sun. Thank you for visiting my website. Smiles, Lark

  3. Hello.I am having trouble to leave my post.I have a question about making compost in plastic containers,I been watching your video and I like it.I live in an apartament and wonder where I can keep my warm farm in the winter ?Could you please give my some clue ?
    I am also interesting in gardening in the bush,I spend 5 months in the bush,close to the lake and I want to start growing my own food up there.I would like to have flowers garden up there too.Could you help ?
    What’s you name Mrs.Lark ?
    Wish you good day and I am waitng for your respond.

    Best Regards


  4. Hi Joanna, Welcome to my website. Click on the forum and start reading. After becoming a member you can post questions. All my members are very nice and helpful. They will need to know your location or zone. I keep my worm farm in the basement. I know that some people who live in apartments keep their worm farm in a closet or near the kitchen. There is absolutely no odor in my worm farm. Biggest mistake people make is OVER FEEDING the worms. WELCOME TO THE WORLD OF GARDENING…WHERE WE ARE ALWAYS LEARNING SOMETHING NEW. Smiles, Lark

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