Whether you have bulbs, rhizomes, tubers or corms, a great many species of plants that grow from an underground storage device have the capacity to multiply or reproduce themselves under the soil purely by vegetative growth or cloning. While many of these same plants can also be grown from the seed they produce, vegetative bulb growth is the speedier and more robust method of reproducing the plant.
Bulblets or Offset Bulbs
Vegetative reproduction in bulbs tends to present itself two ways. The first is when small bulblets grow semi-attached to the parent bulb so that they are connected at the same root plate at the bottom of the bulb. The second manner produces semi-detached bulbs that colonize off of tuberous roots from the parent but are not connected in one mass. Each of these types of bulbs will grow and mature over successive seasons.
Dividing Reproduced Bulbs
Bulbs that have reproduced and naturalized in a garden or landscape can become crowded over time with little soil between them. This can impede the foliage health and flowering performance of the bulbs. Colonies of reproduced bulbs can easily be dug up and split apart and then replanted at wider intervals to give them room to grow and cover a wider swath of soil when in bloom. These divided bulbs will in turn mature and throw off yet more bulbs. Bulbs can also be dug up and used in containers, given away or sold commercially.