Last week I told you about who plant breeders are. This week, we'll talk about what they do.

Breeders travel around the world for undiscovered specimens to cross with existing plants. The Wave petunias were bred by a Japanese beer maker searching for new hops in South America. He brought one of the wild petunias back to Japan and crossed it with garden petunias and Voila! A petunia that revolutionized your flower bed.

Sometimes, they stay at home. Jim Ault at the Chicago Botanic Garden and Richard Saul at Itsaul Gardens in Georgia crossed 2-3 native North American coneflowers to get the new yellow, orange, and reddish-pink echinaceas that are so popular for late summer perennial borders. The Meadowbrite series came out of Chicago and the Big Sky series came from Saul's efforts in Georgia.

The mechanisms of plant breeding are simply taking pollen (male) from one parent and putting it on a receptive flower stigma (female) of another parent. This is called a cross. Think of breeders as really tall bees.

The difficulty lies in keeping ONLY the parent pollen on the stigma. To this end, breeders put bags around each flower to prevent foreign pollen. If you are lucky, the flower you are breeding is self-incompatible (unable to be pollinated by itself) or male sterile (makes no pollen). If not, breeders must emasculate each flower (remove self pollen). This is generally hand-done, a very labor-intensive work.

After the flowers are fertilized, the seeds begin to grow. If the cross is between 2 different species, the seeds may not grow to maturity on the plant and must be grown in tissue culture. This is a method of growing plants in a lab under sterile conditions with artificial hormones and nutrients given to them in a gel-like substance.

When the seeds are collected the results of the cross are planted and evaluated for beneficial characteristics. Often further crossing is done, either back to one of the parents, or among siblings, or to something else entirely. Once a breeder is happy with the result, the plants are trialed.

Trialing takes 2-5 years, at various locations around the country, comparing the new plant to what is already available in the marketplace. Who needs another red geranium if it isn't better than the ones already for sale?

I will add one caveat- when several breeders are working on one new thing sometimes the first to the market isn't the best and everyone gets burned. Be sure to ask at your garden center if they have had good experience with a new variety before you try it.

Next spring when you are looking closely at your favorite flowers, find the pollen and the stigma and rub them together. Who knows, it might become a passion for you, too.