Plant Propagation Techniques
There is nothing more amazing that putting plant material in a growing medium and having tiny baby pants develop. For miniature gardens, these homegrown mini-plants are essential if you want to control the size of your plants and also the number of them. When I want to propagate a lot of material, I take cuttings from inexpensive plants I buy in garden centers, hardware stores, and grocery stores. I also use plants growing in my yard and in my neighborhood.
When I need a mature, high quality plant, I buy it from Meehan’s Miniatures, Meadowbrook Farm, or online miniature plant sources, especially Two Green Thumbs (owner Janit Calvo writes a great miniature gardening newsletter). Keep in mind that some plants you buy from professional growers may have propagation restrictions and you may not be able to use them as source material. Also, the miniature plant growers mentioned here and in other posts on this blog provide high quality, rooted and healthy plants that should last a long time. Your homegrown ones may be as strong or not last as long.
Propagating plants for a miniature display requires an eye for proportions as well as good timing so the plants are the correct size when they are needed. Here are some guidelines for your own miniature plant propagation. Remember that for the Philadelphia Flower Show, the miniature plants used must be rooted (if they are on the list of plants submitted to fulfill the 8-plant requirement). The times for each propagation technique indicate a rooted and growing plant.
Seeds (3-12 weeks)
Plant seeds in a growing medium and keep damp. Bottom heat can help some seeds germinate faster. Give the seedling a lot of light after they emerge or they will get leggy. Some seeds, like those of wheat grass and other grasses, may sprout and grow very quickly so they are very useful for getting large areas covered with plant material in a short time.
Stem cuttings (2-4 weeks for soft, 6-12 weeks for hard)
Take a cutting from the end of a branch, remove the lower leaves, and cut a 45 degree angle in the end with a razor. Place in a mixture of 50% peat and 50% sand. Rooting hormone is optional. Keep cuttings damp but not wet. Tip cuttings from soft stem plants tend to root easily but stems that are hard are a lot more difficult to root. I would use rooting hormone with them but they may still rot before they root.
Leaf sections (4-8 weeks)
Cut a leaf from a begonia or other plants with prominent veins and cut it into sections that have one large vein each. Stand upright in peat/sand mix. Or cut across the veins in a whole leaf and pin it down to the surface of the peat/sand mix. Cut Sanseviera into sections, let ends dry, then insert larger end into mix. Rooting hormone is not needed. Keep slightly damp.
Whole leaf (4-8 weeks)
Take a whole leaf from an African violet (Saintpaulia), peperomia, begonia, hoya, or other plant with fleshy leaves. Trim the stem to about one inch. Insert in mix of peat and sand up to the bottom of the leaf edge. Keep slightly damp.
Succulents (4-12 weeks)
Remove a leaf from the succulent and let the end callous (dry) for a day. Insert in a sand/peat mix and a small plant will grow from the base. Keep the growing medium almost dry or the leaves will rot.
Offsets (1-6 weeks)
Some cacti and succulents (especially Haworthia) grow in clumps with immature offsets at the edges. Detach one of the offsets, allow the end to callous, and insert into peat/sand mix. Some of the offsets may already have roots so will start growing immediately.
Runners (2-6 weeks)
Plants with runners (like Chlorophytum comosum, the spider plant, or many Saxifraga) have baby plants hanging from long stems. The baby plants can be cut off and rooted or can be kept attached, placed in a rooting medium while still attached, and then detached when they have their own roots.
Plantlets (1-4 weeks)
Some plants, like Kalanchoe daigremontiana, produce baby plantlets along the edge of a leaf. When the plantlets are fully formed, remove them from the leaf and plant in a sandy soil mix.