Now that you have mastered the art of taking perfect cuttings, the next challenge is to keep them alive long enough to root and become a plant. Cuttings are a lot like newborns; they need attention and TLC to survive.
Once you have your cuttings in the growing medium mist them water from the spray bottle and place them in the tray. Mist the inside of the clear humidity dome and place the dome over the tray. The cuttings need some ventilation and a couple of small holes in the dome will usually do the trick.
This step is critical; the cuttings have no way to replenish lost moisture without roots. Remove the dome and mist the cuttings 2 or 3 times a day. This keeps the cuttings from drying out and also refreshes the air under the dome. Don't forget to mist the inside of the dome before you replace it on the tray. The humidity under the dome needs to be about 90% until roots appear on the cuttings. Be careful that the air under the dome doesn't get too warm, if it does, you may have to increase the amount of venting (just poke more holes in the dome), and increase the number of times you mist the cuttings per day. Cuttings need to be kept between 72 and 80 Fahrenheit. Too hot or cold will inhibit root growth. If you live in a cold climate you may need a heated propagation mat.
The cuttings need light. The light should be bright, but not too intense. If you are leaving your cuttings outside, put them in an area that receives the most filtered sunlight during the day. Indoors you can use a double tube fluorescent fixture with both a cool white bulb (6500 Kelvin) and a warm white bulb (3000 Kelvin) in the fixture. This will give a good, balanced light spectrum. Most older fluorescent lighting (T8's and T12's) don't penetrate so you must keep the lights very close to the plants (1-2 inches above the plants). If you are using a metal halide or high pressure sodium fixture you must keep the cuttings much further away (2 - 3 feet away for 175 - 400 watt bulbs and 4 - 6 feet for a 600 - 1000 watt bulb). The lights should be turned on for 18 to 24 hours a day.
Water the cuttings with either plain distilled water (or other quality water), or you can add a very mild fertilizer made specifically for cuttings such as Olivia's or Clonex cloning solution. You can also use a 1/4 strength general purpose hydroponic fertilizer solution. Don't forget to adjust the pH of the water / nutrient solution (5.5 for rockwool, 6.5 for most everything else).
Water the cuttings every 2 days unless you live in a very dry climate then you should water every day. Never let the growing medium dry out. Do not let it set in water either, or the stem will rot. A great way to water the cuttings is to use two trays, one with holes and the other without. Fill the tray without holes about half way with water and then slowly lower the tray with the holes holding cuttings into it. Let it sit in the water-filled tray for a few moments and then slowly raise the tray back out and let it drain.
After about a week test to see if your plants have started to root. Remove the humidity dome and leave it off for an hour or two. If the plants have not wilted at all, they probably have enough root development to support themselves. If no wilt is noticed, leave the dome off, if they wilt, spray the cuttings and dome and replace the dome on the tray. Once you have determined that the plants have sufficient root structure to support themselves, stop misting the cuttings and leave the humidity dome off. Once the plants have roots, constant misting can actually be harmful to the plants.
If the lower leaves turn yellow and die, don't worry, it is perfectly normal. The plant feeds off of itself to sustain life, moving valuable nutrient and water from the older growth. Do not remove any dead growth until the plant is well rooted. If you remove the dying growth, the plant can starve and die completely.
When the cuttings are completely rooted you can move them into your hydroponic system or soil. Now you have cloned or created a rooted plant genetically identical to the mother plant.
Cloning is easy once you get the hang of it. You must always remember that every step must be done properly, if anything goes wrong you will get less than satisfactory results.
Many hydroponic systems are available specifically for cloning plants such as Power Cloner, Clone Machine, and EZ-Clone that increase the success rate of your cuttings taking root and greatly reducing the amount of manual labor by automating the watering cycles of the cuttings while providing highly oxygenated water to the cuttings. These ssystems can do as few as 4 cuttings or up to several hundred in a single system. Many hydroponic systems use no growing medium at all; once the cuttings form roots you simply transplant them your growing medium.
Don and Sandy Landers are owners of Dream Garden Hydroponics, LLC, 26380 State Route 7 Marietta.