Answer: With the exceptions of a few such as rhubarb, asparagus and some herbs, most vegetables are annuals that need to be replanted each spring. If your plants did reseed themselves, you would probably find that the seedlings are inferior to the parent plants if you planted hybrids last year. (Most varieties are hybrids.)
To limit weeds in the garden, you might try using an organic mulch several inches thick in between the plants you set out, or in between your rows of seeds.
Here are "weed gallery" sites you may find useful.
Good luck with your vegetable garden this summer!
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