Owning your own seed stock is money in the bank. If you buy quality seed to start your stock, you will want to maintain that quality and purity for years to come (possibly the rest of your life).

Several rules apply when saving seed - do not allow cross pollination on certain plants - curbits are one. IF you are going to save seed from cucumbers- do not grow other curbit plants anywhere near them. I refrain from growing any curbits on the year I choose to grow seed of a particular curbit. The seeds you get from one year can be enough for 10 - 20 years if you handle the seed properly so you only need to grow "for seed" to re-fill your stock.

Many plants easily give up their seed and it can then be dried, enveloped, labeled and stored. Tomatoes, green peppers, onions, beets, cabbage, cauliflour, brussel sprouts, zucchini and many others are generally not a problem to collect seed from as they do not cross pollinate easily and many can only be deliberately cross pollinated.

Potatoes seed saving needs extra care since a single potato blight can wipe out a whole crop. Some say saving potatos for planting every year is a bad idea but I haven't had any problems saving potatoes yearly for 12 years. The trick is to store them in a clean dry environment and after cutting them to seed size - let them dry before planting (some say wipe them with a cloth with some bleach on it and let it dry). And, if you have good microbial populations in your soil - your crop won't go rotten in the ground on you so keep your soil healthy. I often save any green spuds to be the seed for the next season since they are not edible anyway.

Sweet potatoes need to be planted indoors over winter and the vines from that plant are cut with a single leaf to start the crop next spring.

Save the seeds of what you eat - yeap - I buy extra of certain and veggies just to have some seed for "trying" something new in the garden. Doing this gives us the best way to grow foods we like to eat. Foods like this are avacado, pineapple, kiwi, plums, nuts and berries. I once got a mango to root but it didn't survive the first winter.

To save your "forbidden fruit" seed - after eating the edible parts, clean and dry the seed before storing it. Some tropical seeds like oranges, tangerines and grapefruits will not want to be chilled (stratified) but most northern types of plants' seed need to be chilled before planting. I have noticed the citrus seeds do need to be dried well before they get planted so they like to go through a "dry spell" to stratify. Note that apples, pears, peaches, plums, cherries and most fruit do not grow true to the parent but if they produce any fruit (bad or good) you have added to the diversity of your wildlife diet. Citrus plants generally do grow true and will do ok in a warm window over winters. So will many tropical plants including tea trees, coffee trees and some tropical vines.

To get most seeds going - plant in a flat to the depth twice as deep as the seed size. Most plants prefer loamy soil but some like a dry sand. This is a trial-n-error stage you must go through if internet information on the seed you are starting is not available.