Cloning is the process of propagating a new plant by cutting a growing tip from an existing plant. The grower uses rooting hormones to help the cutting establish roots and become a new plant genetically identical to the parent plant. This is the only way to get a plant with the same characteristics as the parent in plants that do not grow from seeds. Hydroponic cloning uses a soilless growing medium and hydroponic nutrients to grow these new plants.
Preparing a Nursery Tray
A nursery tray with a plastic dome works well for cloning plants. You can fill this tray with a soilless growing medium such as rockwool or a perlite and vermiculite mix. You should start with a moistened mix. Soaking the growing medium in hydroponic nutrient solution and draining it well should leave it moist but not soggy. For best results, you can place the nursery tray on a plant propagation heat mat and keep it covered with the plastic dome to keep the root zone warm.
Your parent plant should be healthy and have the characteristics you want in the new plant, such as size or color. The cutting should include a short section of a growing stem with several branch points. A sharp razor will make a clean cut and cause minimal damage to the parent plant; make your cut at a 45-degree angle on the stem. To start the cutting, remove the first two leaves above the cut, dip the cut in rooting hormone and place it into the growing medium. Planting the cutting deep enough to bury the points where you removed the first two leaves will allow more root development.
Lighting requirements will vary by the type of plant you're cloning. Most plants will need plenty of bright light to become established. Fluorescent grow lights placed less than 6 inches above the top of the plastic dome will help if you don't have a window that provides enough sunlight. Your new cuttings should receive 16 to 18 hours of light each day.
A well-ventilated location with a daytime temperature between 70 and 75 degrees will give your cuttings the best chance to grow. You should set your propagation mat under the nursery tray at 80 degrees to keep the root zone a little warmer and encourage good rooting.
Keeping your hydroponic plant cuttings at these temperatures and maintaining the humidity around 90 percent under the dome will help grow compact, bushy plants. You will need to keep the soil moist but not soggy with hydroponic nutrient solution. Removing the dome once a day and leaving it off for a few minutes will give your new plants some air circulation and help prevent disease.