Question
I have started re-using seeds from my bell peppers and heirloom tomatoes.  I would like to expand this to my other vegetables. (carrots, onions, zucchini, cucumbers, muskmelon)  

First off, what is the best way to re-use seeds for carrots and onions?  Can it be done?

Second, how long do the other 3 vegetables need to be left on the vine before I can remove seeds to replant?

Finally, (sorry so many questions)...are there any vegetables that you can have luck with replanting Hybrid seeds, or should you strictly use heirloom seeds?  Would my hybrid sweet corn grow as well next year?

I live in Minnesota.  Thank you so much!

Answer
Hi Kim,
Thanx for your questions.

Carrots and onions are biennials.  This means that the plants spend the first year growing and the next year they blooms, make seed and die.  Carrots will cross with wild Queen Anne's Lace which is a wild relative of the carrot and the seeds from this cross will be inferior.  If you live in an area where the ground freezes, the carrots and onions probably won't survive the winter so you must dig them up and store the onion bulbs like you store other bulbs for planting next spring.  The carrost can be stored in damp sand and keep both the carrots and onions in a cool, dark place where it does not freeze.  Replant in the spring after the last frost and allow them to go to seed.  Carrot seeds will last a couple of years but onion seeds are only viable for about a year. For the cucurbits (squash, cucumbers, melons) you must leave the fruit on the vine and allow it to ripen and become completely ripe.  Open up the fruits and scoop out the seeds.  Allow the seeds to dry and they can be planted immediately.

You can try using hybrid seeds but the resulting fruit will not resemble the fruit from which you got the seeds because of the hybridization.  Many of the results will be very inferior in quality.  Hybrid corn will grow but again, the results will be questionable.  You can use true hybrid seeds that have been bred for hybrids but I wouldn't save seeds from the resulting plants.  I love heirlooms and pretty much prefer them for best flavor.  But, one of the drawbacks of heirlooms is that they may not be as disease or bug resistant as some hybrids.  Also, they may not be as productive and sometimes the fruit isn't as uniform or "pretty" as hybrids.  I hope this helps.
Tom