Vegetative propagation uses the existing part of a plant to create new plants. Vegetative propagation is different than growing plants from seeds. Instead of relying on the genetic recombination that occurs when using seeds to grow a plant, vegetative propagation produce a genetic clone of the original plant being propagated.
Therefore, a rose bush created through vegetative propagation will have the same genetic material and traits as the original rose bush, and the same is true of a tomato plant created through vegetative propagation. Vegetative propagation works because the existing parts of a plant contain the biological information necessary to initiate the growth of the entire plant. These plant parts may be stems, leaves, roots, or rhizomes.
Growing New Plants from Plant Parts
These different parts of the plant can be used in a variety of methods to propagate the plant. Some methods use above-ground plant parts, while others use the underground parts of the plant. Additionally, other methods require the plant to heal a wound in its structure to allow for the development of new plants.
Each method has different requirements for speed, simplicity, and necessary tools to propagate the plant. Timing in vegetative propagation can be faster than growing a plant from a seed. Using established plant tissue instead of a seed allow for the plant to be grown within a single growing season.
For instance, hostas can be divided in the spring and will have grown and flowered twice as much than the original hosta plants by the summer. Additionally, using the runners that naturally extend from the roots of a strawberry plant will lead to the development of new plantlets within a few weeks. The ability of vegetative propagation to be rapid in its development is beneficial to nurseries or gardens that wish to fill in empty spaces within their gardens with new plants, or to replace a plant that is lost.
The specific part of the plant that is used for vegetative propagation is also important. For instance, stems contain the nodes of the stem, which are the specific locations on the stem where new roots will grow. Additionally, certain leaves contain the information necessary for the leaf to develop into a new shoot and plant.
Roots and rhizomes contain the food and the buds that will become the new plants, which can be divided to move an existing plant. Therefore, recognizing which part of the plant is to be propagated allows for the correct method to be selected. The mechanics of vegetative propagation often follow certain sequences.
For instance, softwood cuttings require the taking of a short tip of a stem, the removal of the leaves at the lower portion of the cutting, and the maintenance of high levels of humidity around the cutting until the roots begin to form. Air layering requires the roots to develop while the cutting is still attached to the original plant. Both methods work due to the forcing of the plant to utilize its energy towards root formation.
Therefore, understanding how to force a plant to utilize its energy for root formation allows for vegetative propagation to occur for numerous types of plants. Tools can be used to aid in vegetative propagation, though they are not required. Using a sharp-bladed knife will allow for the cutting of the plant tissue to be minimized, as well as help to minimize the chances of the plant rotting from the cutting.
Using a humidity dome or plastic bag will help to retain the moisture from the leaves of the cutting, so they dont dry out before the development of the roots of the cutting. Using bottom heat will speed the metabolism of the cutting, as will using bottom heat to allow the cutting to grow at a faster rate in cooler rooms within the greenhouse. Many gardeners fail at vegetative propagation due to the neglecting of these tools and techniques to aid vegetative propagation.
The season in which vegetative propagation takes place will impact the success of that propagation process. Using vegetative propagation techniques with living plant tissue is faster than growing the plant from a seed. Additionally, vegetative propagation methods can utilize the seasonal growth of a plant.
For instance, spring is a good time to use division and soft growth techniques for plants, since plants are growing upwards at a rapid rate during the spring season. Summer is a good time to use runners and semi-ripe cuttings. Autumn is the best time of year to use bulbs or root division techniques, since plants will go dormant during autumn.
Winter is a quiet season for growth above the ground, but it is an effective time to use hardwood cuttings and grafting methods. Therefore, using a seasonal calendar will allow for each type of vegetative propagation to occur during the season in which it will be most successful. Mistakes in vegetative propagation often occur with moisture levels and lengths of cuttings of the plant.
For instance, providing too much water to a propagating plant will exclude the air from contact with the soil, which will lead to the rotting of the plant tissue. Cutting the plant too long will cause the cutting to attempt to support the weight of the leaves, which have a great amount of surface area, relative to the root system that supports the cutting. Additionally, placing the cutting in direct sunlight will cause the leaves to continuously lose water through transpiration, faster than the cutting can replenish the lost water.
Therefore, mistakes can be avoided by keeping the growing medium of a cutting only damp, keeping the cutting as short as possible, and avoiding direct sunlight until new roots are visible from the cutting.