Serpentine layering is used for plants with long supple stems (vines, for instance) which travel close to the ground. A number of plants may be obtained from one stem by covering it with earth at different points; the tip should always be left exposed, however.

Air layering is a very modern and popular method, adaptable to trees and woody plants. A portion of a straight branch or stem is cleared of bark down to the wood, and surrounded with moist sphagnum moss. The moss should be kept damp. Some manufacturers provide plant food and hormone which can be rubbed into the cut, and a plastic wrap for the moss which is also impregnated with plant food. After the notch or stripped area has rooted well, the branch is cut off and replanted.

Seed Propagation

Annuals can be grown readily from seed in most cases. The method of growing depends upon the delicacy or hardiness of the seed, and may require planting in frames or pots initially, transferring to the bed only when the weather is sufficiently mild and the plants well grown. Many perennials and biennials may also be propagated from seed. This method, however, is not suited to all perennials, and some of the methods already discussed will yield more fruitful results. Typical perennials which can be propagated from seed are: Hollyhock, Christmas rose, Columbine, Bleeding heart Baby's breath,Foxglove Butterfly weed, Primrose, Larkspur.

Outdoor Seed sowing

Depending on the variety of seed, most annuals and perennials which can be grown by this method can be planted in seedbeds outdoors. The time for planting varies. A few can be sown in autumn, but most, however, should be sown in spring, and, to be safe, not before the last frost has passed. The big disadvantage of outdoor sowing is that one sacrifices control over the circumstances under which the seeds will germinate. In an indoor hotbed, or coldframe, conditions of moisture, heat, etc., can be regulated. Not so in the outdoors, where dryness or changing weather can destroy the weaker seeds quickly. If an outdoor seedbed is planned, choose a spot with good soil. Then work in a portion of your compost pile, pulverizing the soil to the depth of 3 inches. Adding some sand and peat moss increases the effectiveness of the bed. Most seed may be planted on the surface, and the deepest one should plant is 1/2 inch. The bed should be well-watered after the seed has been broadcast over the entire area. The bed can then be lightly tamped.