For years commercial horticulturists have been taking advantage of the multiple advantages offered by asexual propagation. These advantages are now being reaped not only by the commercial growers but by hobbyists as well. One of the largest advantages of asexual propagation is the reduced time it takes for a plant to reach maturity or get to a sellable size. This has obvious advantages for the commercial grower but the advantages extend to the hobbyist as well. The faster the plants can reach maturity, the longer the hobbyist can literally enjoy the fruits of his or her labor. Asexual propagation also gives the gardener the ability to create identical replicas of the most prized plants. This can be especially advantageous for the vegetable grower who wishes to replicate the plants with desirable traits. The best tasting tomatoes or crispest cucumbers can be perpetually grown and cloned in a hobby greenhouse and enjoyed year after year. Aside from flavor and aroma, plants can be cloned to preserve other desirable traits like a heightened resistance to stress or disease. Cloning by taking cuttings is the most common asexual propagation technique used by the hobbyist.
This technique is very effective on a wide variety of plants and is also relatively easy to master. The process of cloning some varieties of plants may only consist of cutting a small branch off the plant and placing the stem in water. After a few days roots will begin to form and the plant can be transplanted into soil or another desired medium. The once part-of-a-plant becomes a plant itself; a genetic duplicate of its donor plant. Spider plants, wandering jew, and coleus are a few plants that clone very easily in straight water and with very little effort.
However, not all plants will root as easily as a coleus. Other plant varieties require a little more attention to obtain a high propagation success rate. These varieties usually root better with the aid of a rooting hormone and more precise control over temperature and humidity. Tomatoes, peppers, cucumbers and many other vegetable varieties clone best in a consistent environment. Geraniums, hibiscus, and some African Violet varieties will root much faster and at a higher percentage within a consistent environment. When cloning these more finicky plants, try to keep the temperature consistently between 72-85 degrees F, especially in the root zone. A seedling heat mat may be necessary to ensure a consistent temperature during the night hours. The optimal humidity for clones during the first stages of propagation is 80-100%. After the plants create their own roots they can be acclimated into the ambient humidity. Humidity domes placed over the propagation trays are a great way to control the higher humidity needs of clones and seedlings without affecting the ambient humidity of the greenhouse. Clones that are kept in a consistent environment will root faster and also have a higher overall success rate.
When taking a cutting off a plant, it is best to do so just above a node site (a site where a branch occurs). A 45 degree angle cut just above a node site is my preferred method for most soft stemmed plant varieties. After cutting, place the clone directly into a rooting compound or water. Not only does this method create healthy clones, it also promotes the donor plant to multiply its shoots.