Typically when a watermelon is ripe for eating, the seeds are fully developed. Any watermelon that is in prime eating condition and has seeds ( no seedless varities) will have viable seed. Of course with hybrids you won't have seeds that are true to the variety. Unless you isolate or bag blossoms open pollinated varieties will cross pollinate and not be true to variety either. Of course if you growing only for seed, an over ripe melon will have seeds already seperated from the flesh and be much easier to collect.

This post was edited by farmerdill on Thu, Jul 3, 14 at 9:16

I agree with farmer dill, I have never had any problems with seed from watermelons I ate. I could imagine a higher percentage of viable seeds if left longer, but that is about it.

farmerd , I'm growing only Greystone this year.Since I presume it's a hybrid, are you saying the seeds won't be true?

That's exactly what farmerdill is saying. There is no way of knowing what the watermelon will look like nor taste like if you save seeds from a hybrid (which Greystone is) and re-plant them next year. If you want to save seeds you need to grow an open pollinated variety.

Rodney

This post was edited by theforgottenone1013 on Thu, Jul 3, 14 at 9:36

Your answers have been very helpful. thank you!

If the seeds are black (or dark brown; somewhat variety dependent) then they are fully mature.

Easiest to just buy seed of a variety or varieties that you like and that do well for you. But if you want to save seed year-to-year, then you need to find a good open-pollinated variety and grow it in isolation from other varieties of watermelon.

If you can't grow a hybrid for seed, then how does the seed company get its seed?.

"If you can't grow a hybrid for seed, then how does the seed company get its seed?"

The discussion linked below goes into great depth regarding how F1 hybrid seeds are produced. But long story short, hybrids are the result of controlled cross pollinating between different open pollinated parents.

Rodney

Here is a link that might be useful: Silly question about hybrid seeds

Thanks for the response and the link. I purposely planted only Greystone this year, because these were my last seeds, and I thought I'd be able to replenish my seed supply, so this news is definitely a bummer.
Greystone was hybridized by Holler Seeds and they sell the seeds through large distributors like Seedway.
Seedway has a minimum order of 1000 seeds, and I'm just a home gardener. So you see the predicament I'm in.

You can always try saving hybrid seed. It may not come true to the parent, but in some cases it may. After all that is how breeding new varieties is/was done. Cross breeding and then selecting for desired characteristics over several generations.

There also are some varieties which are labeled as hybrid but are not. I've always suspected that it was done to keep people from saving seed.

Anyway if you have the watermelons growing now, might as well save some seed and give them a try next year. It may or may not work out, but you have little to loose other than some wasted space in next years garden.

rayrose(8) re: Greystone 1000 seeds

I know this is several years late. But just a thought, perhaps you could buy as a group with friends in a fb garden club, your neighbors... And still have seed to replant