You can enlarge your plant collection inexpensively by propagating the plants you already have using cuttings or divisions. You also can grow many plants from seed.
Buy seed from a reputable company. For best germination, use fresh seed. If you have to store seed, keep it in dry containers in a cool, dark place.
Sow seeds when the seed packet directs. Plant on a small or large scale. A 6-inch pot easily accomodates from 1 to 100 seedlings, depending on the plant grown. Use trays or flats for large quantities.
Many plants produce several stems with roots attached to each stem. Each of these rooted stems can be divided from the parent plant to make a new plant.
1. Remove the plant from its pot. Early spring generally is the best time to divide plants. Press your thumbs into the middle of the plant, grab the plant with both hands, and tug it apart. If that fails, cut the plant with a knife.
2. Keep a large clump of roots with each division. Immediately pot the new plants in potting soil.
3. Keep the soil evenly moist the next few weeks to help heal the injured roots. Place plants out of direct light until they start to grow. Move them into brighter light over a period of 10 days.
The growing tips of many plants will produce vigorous new plants when cut and rooted properly.
Leaf cuttings produce new plants much the same way stem cuttings do, except a leaf stalk rather than the central stem is used. Depending on the plant, use either the whole leaf or parts of the leaf. Generally, for small-leaved plants, use the entire leaf; for large-leaved plants, leaf sections.