Any tips for watermelon seed germination?

Hello everyone,

Im not sure why but my watermelon seeds always seem to poorly germinate. Ive tried both the paper towel bag method as well as in a humidity dome in seed starter mix, both methods tried with a heating mat. Any other tips or tricks im just missing?


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I’m assuming by paper towels method you mean water in a jar with a paper towel rolled up in the jar wicking up water on a sunny window ledge? That’s how I do it with all seeds that need extra TLC.

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Start with good quality hopefully fresh seed. Seed older than a couple of years are not likely to germinate very well.

Heat, water, and oxygen are needed for most seed to germinate. Putting watermelon seed in a plastic bag can delay germination if there is not enough air in the bag. Too much moisture or too little moisture can cause problems.

I start watermelons in soil blocks. These are made with 30% peat moss and 70% clay based soil. If you have sandy soil, you will have to change the mix to get it to adhere. Look up “how to make soil blocks to start seed” to find articles. Watermelon should never be kept indoors more than 2 weeks after germination.

Last caution, triploid or tetraploid watermelon seed have a very thick seed coat which can interfere with germination. If you are trying to grow these, look up ways to score the seed coat so it won’t cause problems.


I never did anything but make a nice hill/bed and plant them in the dirt. 3 seeds a couple inches apart… easily thin as needed.

A week or two after you plant your tomatoes works for me.

I direct sow just about everything… but tomatoes.


I can germinate cantaloupe in 3 days and watermelon in 4 days outside in March by using a heat dome by day and heavy insulation at night. Plant the seeds about one inch deep, cover with black weed barrier, water, and during the day cover that with clear plastic. At night cover with 3-4 inches of insulation. It even works for triploid watermelons.

It does require sunny days. And you better check regularly or you’ll have seeds up and damaged by lack of light.

This is just for fun and requires a lot of effort. But I’ve done it several yrs with good success.


4hrs of 2% hydrogen peroxide in the dark. I scarify all seeds from raspberries and blackberries to vegetables this way…

I used to use bleach but the peroxide works just as well and much easier to use with same or better results.

Plenty of research studies to read on this online. Just type in H202 scarification and whatever thing you want to germinate…theres probably a study done on it. Also lots of youtube videos.

If you dont want to do this you can physically knick the seed coat on the rounded end of the seed with nail clippers or a file or sandpaper to allow oxygen and water to enter the seed.

There are also the warm water for 24 hour guys…

Peroxide works for me and is really easy. I do mine in the cheap little bathroom cups from the dollar store


Wow thank you all for all the great information! I really appreciate it!