Asexual Plant Propagation Plant Propagation The reproduction of new plants from seeds or vegetative parts of a plant. Asexual Propagation The reproduction of new plants from the stems, leaves, or roots of a parent plant. No seeds are used, just portions of the parent plant which are placed in soil Benefits of Asexual Propagation Produce plants faster Disease free stock Works when seeds are hard to germinate Plants produced are genetically identical to the parent plant Clones Plants with or without reproductive parts can be produced Less Expensive in some cases Types of Asexual Reproduction Cuttings Grafting Budding Layering Dividing Rhizomes Stolons Tillers or Suckers Where Can Cuttings be Taken From? Stems Leaves Roots 1
Stem Cuttings Softwood Cuttings Herbaceous Cuttings Semi-hardwood Cuttings Hardwood Cuttings Conifer Cuttings Softwood Cuttings Taken from soft, new spring growth of woody plants Root easy but require more attention Usually 3 to 5 inches in length 2 or 3 nodes Cut at 45 degree angles ¼ inch below a node 1/3 of lower leaves are removed Herbaceous Cuttings Also considered softwood cuttings Numerous succulent greenhouse plants 3 to 4 inches long Contain several leaves Root easily Semi-hardwood Cuttings Woody, broad leaved plants Taken in the summer from new shoots 3 to 6 inches in length Handled the same as softwood cuttings Hardwood Cuttings Prepared during the dormant season Deciduous or evergreen plants 6 to 8 inches in length Taken from year old wood Form callus tissue during the winter Develop roots in the spring Conifer Cuttings Early winter Narrowleaf evergreens May take several months to produce roots 2
Leaf Cuttings Consist of a leaf blade or leaf blade with petiole Used when plant material is scarce Used when a large number of new plants are needed Houseplants or foliage plants Leaf Cuttings Cont. Leaf blades can be cut into pieces and inserted into medium Some leaves can be cut on the primary veins and laid flat on top of the growing medium. Leaf and petiole cuttings are place petiole down the medium Leaf Bud Cuttings Consist of a leaf, petiole, and a short piece of stem with lateral bud. Must have well developed buds, and healthy, actively growing leaves. Insert in medium with the lateral bud just below the surface See Figure 5 in handout Root Cuttings Made from root pieces of young plants During late winter or early spring Roots are dug, cleaned, and treated with fungicide 2 to 6 inches in length Placed horizontally or vertically Quite laborious Rooting Hormones Material that promote the development of roots Applied to the bases of the cuttings Powders or Solutions Do not use too much, it may cause the stem to rot Root-Inducing Environment High humidity to reduce water loss Indirect sunlight Growing medium 3
Types of Growing Medium Peat moss & perlite mixture 1 to 1 ratio will hold moisture and provide aeration Vermiculite Sterile and has high moisture retention Sand Provides aeration but does not retain moisture Sand & peat moss mixture 1 to 1 or 2 to 1 ratio, increases moisture retention Grafting Method of asexual plant propagation that join plant parts so they will grow as one plant. Turn to page 361 Cleft Grafting Bark Grafting Scion Layering Portion of attached shoot is partially buried underground where roots develop New plant separated from parent plant Figs Raspberries Blackberries Dividing Plants that form clumps that may be dug, cut apart and form new plants. Daylilies Mums Daffodils Rhizomes Plants that produce underground stems called rhizomes can be dug, cut into sections and the sections planted. New plants and roots grow from joints on the rhizomes. Iris Bermuda grass Johnson grass Stolons Plants that grow horizontally along the soil surface. New plants are produced at joints along the stolons. 4
Tillers or Suckers Formed at the base of some trees, tillers/suckers may be cut free from main plant to form new plants. Blackberries Rabbit eye blueberries Raspberries Grasses Summary Asexual propagation is the propagation of plants from stems, leaves, or roots of a parent plant Cuttings are the most popular form Cuttings are often treated with a rooting hormone The environment is very important for successful rooting 5