Vegetative reproduction in plants can be useful because all the progeny will be identical to the parent plant. For horticulturalists, this may be useful if you get an unusually attractive shoot (or sport) from an otherwise unremarkable plant. Commercially, it makes sense to propagate this attractive shoot to produce new plants but if you use seed, the seed will produce plants of the parent type and you may not get the unusual characteristics of the sport.
Growers often divide clump forming plants ot produce many new plants from one strong parent and theyt know these plants will have all the characteristics of the parent. Seed propagation carries with it the chance of genetic variation but using vegetative means will result in a sure supply of the same type of plant and you can use one plant to obtain many cuttings.
Plants naturally use vegetative means of propagation and sometimes, this can be more successful than relying on seed production because sometime, spreading by vegetative means can be done before the plant is capable of flowering and making seed.
Type of vegetative propagation include Chinese layering – where the uppermost main stem is cut, sealed with a plastic bag, the wound filled with moss and left for a year. New roots will form in the moss from the cut due to chemicals in the plant called auxins being stimulated. These are the plant equivalent of hormones and will form roots. The new plant can be cut from the parent after the first year. This is suitable for shrubs with supple stems.
Ordinary layering is used for shrubs with bendy stems which you can bend to the ground. Again, a clean wound is made and the stem pegged into the ground at the site of the wound. New roots will form and a new plant can be removed from the parent plant after a year or so.
You can divide clump-forming plants by gently teasing the root ball apart with the back of a fork. Sometimes, you can gain several new plants and keep the parent plant from one root ball. This is popular with perennials and biennials.
Plants naturally propagate themselves vegetatively using runners (underground shoots) or stolons (underground rots). They send these out and when a suitable place is found, the new shoto emerges, makes roots and a new plant is formed. Many invasive plants and weeds spread in this manner as many gardeners know.
Growers can propagate vegetatively by taking cuttings. You can use that years soft growth (soft wood cuttings,) last years growth (semi-ripe cuttings) or last years woody growth (hard wood cuttings) depending on the type of plant and the techniques are similar but with subtle differences and take different amounts of expertise and time according to the plant used. Softwood cuttings are hardest as the cuttings are very vulnerable.
You can also take cuttings from roots and evenleaves if you have the knowledge.
Bulbs are another way plants propagate themselves naturally by vegetative means. Offsets are baby bulbs produced from the basal plate, to which the adapted leaves which form the bulb are attached. These will eventually spread out, increasing the area of plants such as daffodils, autumn crocus and others or gardeners can speed up the process by removing the bulblets with a sliver of basal plate and propagating them in pots.
For plants, any means of propagation is acceptable and seedin just one way of doing sdo. Many plants produce far more successfully by vegetative propagation than by seed and although it does nto allow fo rgenetic variation, so adapting to climate changes or natural disasters is not an option, vegetative propagation remains a fascinating area of horticulture.