Growing plants from seed is one of the most exciting, as well as economical, gardening practices. When you plant a named variety of a rose, an Iris or a day lily you know in advance exactly what the flower will look like, but if a packet of mixed zinnias or asters are sown you'll be in for a lot of pleasant surprises. Very likely you will see colors that you never knew existed; shades, In fact, that very likely don't even appear in the seed catalogs. So, just for the fun of it, try growing a garden from seed.

You can raise both annuals and perennials from seed, the latter class take longer to mature (that is why they are frequently started in the fall) but they live for two or more seasons. Many perennials that can be propagated from a tiny seed will become permanent assets in your garden. On the other hand, annuals are plants that complete their entire life cycle in one growing season. They germinate rapidly and bush right along to the flowering period. They are rushed for time and consequently will bloom in a hurry.

No matter whether annuals or perennials are planted make sure seeds are fresh. The best way to insure the viability of the seed is to purchase only from a reputable dealer. Flower seeds, like all other seeds, lose their viability over a period of years. Curiously enough, the germination percentage may rise in a given year but over a period of years it gradually decreases entirely. If you wish to keep seed from one year to the next make sure it is stored in an atmosphere of low humidity and temperature.

One of the best mediums for starting seed indoors is a regulation nursery flat. This is the kind of container in which established transplants are usually sold in garden supply stores. The seed flat 'measures roughly about 18x18 inches and is perhaps two inches high. You can always borrow one from your neighborhood nurseryman.

When you get ready to plant be sure you have the right soil mixture. Just what is right for years has been a controversial subject among nurserymen, and probably always will be. Generally speaking, a mixture of one part No. 2 sand and one part peat moss should suffice. This type of starting soil minimizes the possibility of weed seed or soil-borne diseases. It is loose, porous, clean and easy to use.

After placing the soil in the seed flat it should be tamped down and made smooth. The top of the surface should be at least one-fourth of an inch below the top edges of the seed flat: This insures the proper level for watering and should keep any moisture from running over the top of the flat. Drills can then be made on the soil surface, using a ruler or a comparable straight edge.

The planting depth is determined by the size of the seed. Correct instructions are always given on the seed packet but a rough average would be about three times the diameter of the seed. Tiny seeds should simply be pressed into the soil. After planting, set the seed flat, in a large container in which the water level is below the top of the flat. Moisture will seep upwards by capillary action. This method of watering is preferable to overhead sprinkling which still will prove satisfactory if an adequate container is not available.

What is interesting to know is that three specific factors are required for germination: 1 temperature, 2 moisture and 3 oxygen. When planting naked seed, especially in the outdoor garden, make sure there is a firm contact between the seed and the soil. Otherwise, moisture will not move from the soil particles to the seed. This is frequently a cause of low germination. It is advisable to have sufficient moisture in the soil to germinate the seed and push the seedlings through the surface.

Watering after planting, but before the seedlings appear may prove disastrous. Watering often causes the surface to cake, thus forming a barrier that the tiny seedling must push through.