Growing most plants from seed is easy, rewarding, and fun. (See my back articles, "Plants From Scratch, Pt II" and "Starting Seeds From Scratch, Pt III") However, there are a few plants I don't recommend starting from seed at all. Others should be attempted only by the experienced or truly adventurous. Some seeds, though easy to germinate, defeat even the most experienced gardeners who don't know the "tricks".
This article will discuss some of the taboos, attempt to demystify several of the less difficult problems, and tell you a few of the "tricks". Most annual flowers and vegetables easily lend themselves to growing from seed. Many vegetables have short enough growing seasons that they are planted directly in the garden. The others are such a snap to start indoors from seed that I won't be considering them at all in this article. This is a discussion of the "problem children", those tricky seeds that seem to frustrate our germination attempts, no matter what we do.
Two popular annuals I never bother with are pansies and petunias. Pansies are difficult to grow simply because they prefer cool conditions. Though I've grown pansies from seed, the germination rate was poor, usually around 50%, the plants were spindly; and, being biennials, rarely bloomed the first year anyhow.
I've never once managed to get petunias seeds to germinate. Not a one. I've tried everything from bottom heat to cold treatment and none of it worked. Since both these annuals are cheap to buy as full-grown plants, and a vast variety of colors and types are readily available, I don't feel guilty purchasing either one as plants rather than seeds.
Impatiens are another annual that is difficult to grow from seed. However, these I do successfully start every year. Germination rates are spotty, ranging from 25-100%. Oddly enough, considering they are shade loving, impatiens need some pretty toasty temperatures to germinate. Provide them with bottom heat from a propagation mat and plenty of moisture by stuffing the flats in clear plastic bags and you should have no trouble starting these beauties from seed. I especially like the doubles, which are pricey to buy as full-grown plants.
