How to Make a Simple Incubator for Germination

About: Due to my lack of free time I may take my time to respond to posts/comment etc.

For many people getting seeds to germinate is one of the hardest things to do in the world of gardening.
This simple incubator not only makes germination easy, it provides a springboard into hydroponics as the plant will not have any soil-borne diseases.

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Step 1: Materials and Tools

Black plastic (I used Panda Film but this regular is fine)
Foam fruit box
Tape (I used masking tape but duct tape is better)
Small fish tank heater (this can picked up for around $20 AUD)
Seedling tray (any kind so long as it fits in the box)


Step 2: Line the Box

Line the inside of the box fill it about 3/4 of the way up. with water.
Then tape down the edges.

Step 3: Set Temperature & Insert Heater

The temperature for germination varies form plant to plant but you can find a good guide to seed germination temperatures here.
For tomatoes we set it to 26 degrees C (78.8 degrees Fahrenheit).
Then place the heater on the bottom of the box with the suction cups facing down.

Step 4: Second Skin

Place a second piece of plastic into the box so it is just touching the top of the water. Then tape the edges down.

Step 5: Put in the Tray

Place the seedling tray into the box then fill each compartment with the Perlite.
WARNING: Perlite is made of silica, DO NOT breath in the dust!

Step 6: Plant the Seeds

Plant one (1) seed into each of the tray's compartments and then turn on the heater. To keep the heat in place a small sheet of black plastic over the top. Once the seeds have sprouted this is not necessary. All that is left to do is wait until the plants are big enough to transfer into either a hydroponics setup or a regular soil garden patch.

That's all for now,

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    17 Discussions


    Reply 2 years ago

    Vermiculite, a mineral substrate that holds more moisture than perlite.


    3 years ago

    Does it really work with the the heater below the tray?


    3 years ago

    We don't have panda film where I come from. Is there any alternative to the panda film? Is panda films heat resistant?


    3 years ago


    It is interesting, I would like to make one.

    any idea how to get the instruction to make it?


    4 years ago on Introduction

    I like the way that this solves moisture, humidity, heat, and most difficult- temperature control, with the use of something as cheap as an aquarium heater. this is definitely the way I am going to go. I've seen something similar using a large, insulated enclosure with seed trays in it, and a pan of water at the bottom with a thermostatic heater in.


    9 years ago on Introduction

    Hey! Thanks a lot! I will be doing a desing practice on biology lab about germination soon and decided to use temperature as the variable but i was struggling on how to control de temperature.. GENIOUS! After planting the seeds you just water them on top.. right? Thanks (:

    1 reply

    Hey, good luck with that I hope it turns out well for you! Watering them after they have been planted is a good idea so the root system has a chance to establish. Keep me posted on how it went.


    10 years ago on Introduction

    Sorry bit lengthy - but to clear it up for all- have a great day What is perlite? Perlite is a naturally occurring siliceous volcanic rock. The distinguishing feature which sets perlite apart from other volcanic glasses is that when heated to a suitable point in its softening range it expands twenty times its original volume or more. This expansion is due to the presence of 2% to 6% combined water in the crude perlite rock. The water became entrapped into the amorphous material on instant cooling after an eruption. When quickly heated above 870ºC the crude rock pops in a manner similar to popcorn. As the combined water vaporises, it creates countless tiny bubbles in the heat softened glassy particles. It is these tiny glass-sealed bubbles which account for the amazing light weight and other exceptional physical properties of expanded perlite. The expansion process also creates one of perlite's most distinguishing characteristics - its white colour. While the crude rock may range from transparent light grey to glossy black, the colour of expanded perlite ranges from snowy white to greyish white. Typical Physical Characteristics Colour: White Refractive Index: 1.5 Maximum Free moisture: 0.5% Specific Gravity: 2.2 - 2.4 Softening point: 870 - 1093ºC Fusion point: 1260 - 1343ºC Specific Heat: 837 J/kg Typical Chemical Analysis Weight % Silicon oxide (SiO2): 76,2 Aluminium oxide (Al2O3): 12,1 Potassium oxide (K2O): 4,9 Sodium oxide (Na2O): 3,4 Iron oxide (Fe2O3): 0,7 Calcium oxide (CaO): 0,6 Magnesium oxide (MgO): 0,1 Manganese oxide (MnO): 0,1 Titanium oxide (TiO2): 0,1 Loss on ignition: 1,9

    1 reply

    Thanks for clearing that up. I've always wondered where they actually get the silica from. (seriously) BTW no matter where it comes from it WORKS! I had seeds sprouting within 4 days!! Take care, Moderator


    10 years ago on Introduction

    "WARNING: Perlite is made of silica, DO NOT breath in the dust!" Huh? I though perlite was made out of volcanic rock. Or it may be my mistake that volcanic rock is silica?

    2 replies
    super moderatorawang8

    Reply 10 years ago on Introduction

    Perlite is silica which is heated under pressure until it pops like popcorn. You may be thinking about scoria which is made form volcanic rock.