There are three basic types of propagation in use by the hobbiest. They are seed, cuttings and air layering. Several other methods,such as tissue culture, are in use commercially but these are beyond the scope of the home gardener.
Brug seed are inclosed in a corky covering. Inside the cork is a small "bean". This is the true seed. The corky covering may be removed or it may be left on. The only difference is that the peeled seed may sprout a bit sooner. Many of the flowers from seed will be white as this is the dominant color in many species. But, that said, we do also get all of our colorful new hybrids from seed. Use fine potting soil or you may use a mixture of sand and peat as a starting mix. Plant the seed about one half inch deep and firm the soil over it. Water well and then do not water again until the soil becomes dry. Too much water for too long a time will rot the seed. Expect germination in from two weeks to six months. Fresh seed do germinate faster. When the seedling has grown its second set of leaves move it to a larger pot. Generally speaking,the larger the pot the faster the seedling will grow.Remember to keep the soil warm in colder weather. Expect blooms when the seedling has reached three to five feet and formed a "Y" on the main stalk. You can see this "Y" on one of the cutting pictures.
Plants grown from cuttings are exact clones of the parent plant. For instance, if you have a Dr.Seuss it has been produced from a cutting of a cutting of a cutting etc. of the original plant and is a part of that plant. It will not cross,and produce seed,with another Dr.Seuss. Select cuttings from older wood.The cutting should be about six inches long and one half inch in diameter or larger. The cuttings may be started in water or in good potting soil. If you start in water,change the water daily and move the cutting to soil as soon as the roots begin to form. If starting in soil place the cutting about two inches into the potting medium, firm the soil and water thoroughly. After this water only sparingly until the plant is well started. Too much water will cause the cutting to rot. Most cutting failures are due to too much water instead of not enough.
Air layering is really just a fancy form of rooting cuttings. It is used for hard to root varieties. Select a branch to make the new plant. Wound the branch slightly,on the bottom side, where you want the roots to form. A one quarter inch nick with a razor blade works fine.Place a large handful of damp peat or soil around the wounded section. Place clear plastic wrap around the whole mess and tape tightly so as to exclude air and keep the moisture inside. You will be able to see the new roots as they grow long enough to reach the plastic. When you have enough roots, cut the branch from the mother plant, remove the plastic wrap and plant in a pot of good soil. Water well and keep this one watered well. Place in a shaded location until the plant is well established. Move gradually into sunlight.Since this method is more trouble it is usually reserved for hard to root varieties.
Make cuttings 4-8 inches long
Place large pieces horizontally
and cover bottom half with soil.
Place several cuttings in each pot.
Separate after they are well rooted.
Rooted cutting at four weeks