Good vegetable seeds are clean, disease free and viable and produce plants typical of the cultivar. You just have to take care of few things about vegetable seeds.

Diseases:
Vegetable seed should be disease-free. Some diseases are carried on the seed coat, such as black rot of cabbage, and can be controlled by seed treatment. Other diseases, such as blacking, are carried within the seed of cabbage and cauliflower and can be fairly well controlled with a hot-water treatment.

Vitality:
Vegetable seed should have enough vitality to germinate, emerge from the soil, and produce the plant. A good stand is important, as a partial stand results in wasted space. Over seeding results in a costly thinning operation, or frequently, reduced yields due to overcrowding.

Water:
Vegetable seeds require water to germinate. They can be divided into five groups, depending on how much water their seeds need in order to germinate. It is important to recognize that this is the amount of water required to produce the crop. The rate of germination is faster at higher moisture levels than at the minimum. The amount of water in soils ranges from field capacity to the permanent wilting percentage. Field capacity is the maximum amount of water your particular soil will hold. Any additional water will drain out of the soil.

Planting Depth and Rate:
Vegetable seed should be planted at a depth equal to about four times the diameter of the seed. This rule or the specific depth must be used with care. In wet weather or heavy soils, seeds should generally be planted shallower. In dry weather or light and sandy soils, seeds should be planted deeper. Some small seeds like tomato, pepper, and eggplant germinate slowly and are often planted in the garden as transplants.

The different methods of processing most common vegetable seeds are grouped into two categories: wet seeds and dry seeds.

Wet Seeds: Squash, cucumbers, melons, and tomatoes. In most cases, these crops need to go through a fermentation process that helps them burn off any seed-borne diseases as well as prepare them for storage. This process is a common one for all of these crops, after a few preparatory steps have been taken. Both summer squash and cucumbers need to be left on the plant for longer than normal; once picked, they have many more mature seeds if left to sit inside for four to eight weeks before being fermented. Winter squash can be picked at the normal time and is best left inside for several months before being processed. Cucumbers should be left on the plant until skins begin to turn orange and wrinkle slightly. Tomatoes should be allowed to ripen as mush as possible – not to the point of rotting, but a little past the point where you would want to eat them. Once the squash, cucumbers and tomatoes have reached this point, the process of extracting the seeds is essentially the same.

Dry Seeds: Beans, peas, corn, lettuce, most flowers, radishes, and onions. These are simply left to dry on the plant for as long as possible. Some seasons are so wet that your seed will rot if not harvested before it is completely dry. The seed is getting its last bits of information from the mother plant at the end, so if it must be pulled, pull the entire plant with the seeds still attached so that they can mature as much as possible.

Saving Vegetable Seeds:

The best way to keep vegetable or flower seeds dry and organized are to store them in little bottles or plastic margarine containers that have a tight-fitting lid. Simply place the extra seeds into the clean, dry bottle or container, and add a few tablespoons of flour or corn meal to each container to keep the seeds dry. Put the containers in a cool, dark place until you are ready to plant again. You can tape a picture from the seed packet on the outside of the container so you will know what seeds are inside the container. If the jar is clear, just place the folded seed package inside so you can see that the jar contains.

If you have room, the best place to store seeds is in the refrigerator. The seeds will keep in the refrigerator, and most still germinate several years after the expiration date.