Depends on the plant. Peppers for instance, you could both eat and harvest for seed from the same plant with no special attention, assuming you're eating the ripe peppers. Other plants, say peas you could do both at different times. Harvest most of the pods while they are edible but leave a few here and there to fully mature and harvest for seed.

Seeds are relatively cheap considering how much you get back out of them though.. I think I'm mostly just going to buy seed every year instead of risking that I didn't do something right or something got crossed. Any seed I do save will only be as a side project and not something I'm going to count on feeding my family. Maybe that will change when I've got a few years of gardening under my belt.. But I'm relatively new, too.

Last year I started a 12x3 foot plot, and this year I upgraded to 208 sqft of raised bed, plus herb plot and berry patches.

This post was edited by IAmSupernova on Sat, Mar 16, 13 at 14:23

I grow most of my stuff from seeds I save.

Seed saving is an art though, different from gardening. They both have steep, complex learning curves. If you are not doing this as a fulltime occupation, you might want to limit how much you try to learn in the first few years :).

Space is also an issue. If you leave plants in the ground after harvest, in order for them to have time to develop mature seeds, that is space you do not have available for the next crop. If you live somewhere with a long or year-round growing season, this is a major sacrifice.

And seeding plants can get big. A broccoli or kale plant is maybe 18-24 inches square when harvesting, but 5 feet tall and 3 or 4 feet wide when seeding. Chard gets to 8 feet and collards to 10. That's a lot of space you are giving up.

Nila raises some good points. You are trying to take on a great deal with little to no knowledge or experience so you might want to slow down a bit and maybe tackle only one issue at a time.

First, you cannot buy GMO seeds. Second, to garden organically you do not have to buy certified organic seeds unless you are planning to apply for organic certification for sales of produce. So save your money. All seeds are 'organic' unless they have been treated with a fungicide and those are labeled as such.

Third, your soil, your garden preparation is the most important aspect of successful gardening, not the seeds. Successful garden prep takes time - lots of it - so I'd suggest focusing on that this year.

Fourth, you need to understand the differences between hybrids and open-pollinated seeds. OP seeds (aka 'heirlooms') breed true from saved seed IF they don't get cross-pollinated. Hybrid seeds usually do not breed true and so saving them is strictly optional.

Fifth, seeds are viable for many years. Any you buy and do not use this year are still good for planting next year IF stored properly. So you need to learn about how to harvest, save, and store seeds.

Sixth, first year gardens are seldom highly successful and the more "comprehensive" they are the less successful they are simply because of lack of knowledge, experience, and soil preparation. So honestly, you likely don't have to worry about many of these other issues this year except to begin learning about them.

When one doesn't know how to swim but jumps into the deep end of the pool anyway they often find themselves overwhelmed, discouraged, and in distress. So start slow and small, focus on soil preparation and a few of the most common easy-to-grow crops. Master those, save seeds from them if they aren't hybrids, and then expand more next year.

Good luck and enjoy gardening. Don't let it overwhelm you.

Dave

But the most important advice is: keep your seeds in the freezer, they will last forever, even those that have a one year life outside the freezer (parsley, parsnip, celery). Then, once you are absolutely sure you want this particular vegetable in the garden forever, buy large packets which cost a fraction per seed. this advice, if followed, will save a lot of money. Many of us use 10 and 15-years old seeds, but only if they were in the freezer.

Good point about hybrid seed, Dave!

And glib, I will go move my parsnip seed stash to the freezer right now. I don't have space there for all my seeds (they are in the fridge, except ones i have huge amounts of), but I can fit the parsnips in :).