Taking Great Cuttings
Have you ever found a great variety of plant that you'd like to replicate over and over so you can have that same great appearance, taste, or smell every time you grow it? Growing plants from seed can have its advantages, but taking cuttings is a great way to exactly replicate the desirable traits of a plant every single time. There are many ways to clone your plant, with certain types of plants showing preference for certain methods of replication. There are many commonly used methods of plant replication including stem cuttings, leaf cuttings, roots division, and tissue culture, to name a few. Stem cuttings are a great way to begin to learn to propagate your own clones.
Stem cuttings are likely the easiest method for plant replication, with many varieties of plant that will root with ease. To get started, you'll need a well-aerated medium such as Grodan, Oasis, peat plugs, or perlite. Use a clean knife or scalpel to cut from the mother plant and remove additional leaves from the lower portion of the clone. You'll want a clean propagation tray with holes for drainage. Also, most plants root more quickly if some sort of rooting hormone is added. You can choose either synthetic or natural sources of hormone. The main plant hormone, which induces rooting, is auxin. Common forms of auxin used in synthetic rooting products include: IBA (Indole-3-butyric acid) and NAA(1-Naphthaleneacetic acid). The naturally occurring auxin IAA (Indole-3-acetic acid) is less stable and therefore rarely used in commercially available rooting products. Two natural solutions that provide auxin and/or cause a plant to induce their own natural auxin production are willow and Azo bacteria. These may be used for natural and organic production of clones. A couple final supplies, which are optional, include a heating mat and a humidity dome. Some plants require neither of these, but many will root faster in a warm, humid environment.
Stem cuttings work best on plants that have a main shoot, rather than plants that form a rosette and have all leaves originating directly from the ground. Some good examples of this type of plant include most trees and shrubs, the colorfulColeus, basil, and mints. The easiest varieties include plants that have nodes.
This is the section along a stem where leaves originate. If you have selected this type of plant to clone, the plant tells you exactly where to cut, and where hormone most easily assimilates and produces new cells for root formation. You cut directly below a node, within ¼", so that plant hormones will move into the node cells and divide to form roots. For plants that do not have this sort of node, you can cut just below a leaf petiole(see picture ), or a branching point. Anywhere that some part of the plant is producing a new shoot can be a decent place to cut below, but you do not want to try to root a cutting that has multiple branches or divisions. This will be too much tissue to support while also trying to induce roots. After choosing your stock, gather your supplies and begin making cuttings of your own.
Steps to taking successful cuttings:
1) Gather your supplies and have your hormone or other rooting product ready for the first cut you make. If you take a cutting and do not get it quickly back to a moisture source, you may end up with a cavitation in the stem, which will prevent the cutting from being able to absorb water, and cause failure of roots to form.
2) Find ends of branches on your mother plant. Using a sterile knife or scalpel, one at a time (while you're a beginner you may work on several at a time once you are more comfortable with the procedures) cut a piece 2-3 inches in length from the mother plant. A great way to leave your mother plant in healthy condition is to cut just above a branch or node, so that it will regenerate right at that location and leave no excess tissue above the new growth. If you do this, you will also have a little extra time before an air bubble can form in your cutting stem. This is because you will then proceed to move from the bottom of this cutting up to the next node and cut just below this node. You will also want to remove any additional leaves or branches from this area.
3) As quickly as you can from the time you remove the cutting from the mother plant, dip or soak your cutting in rooting hormone. There are many different products available, which have slightly different methods of use. Some rooting hormone products, such as Drip-N-Gro are fully water soluble and rely on the plant to use capillary action to pull the hormone into the vascular system. When using fully soluble hormone products, you will make a solution and soak your cuttings for up to 5 minutes before transferring them to their rooting medium. Another product type is powdered hormone. Hormex is a powdered rooting product that has been used for many years in both hobby and professional horticulture. You will dip your cutting into the powder and then immediately push your cutting into the rooting medium. A third class of rooting hormone products, rooting gels, has become very popular because they help prevent cutting bases from drying out by coating them with a thin layer of watery gel. Clonex and Olivia's Cloning Gel are two great products in this category. Dip in the gel and then right into your rooting medium. For a natural start for your clones, use Azos from Xtreme Gardening made into a thin paste. Roll your cuttings through and then place in your medium. The Azo bacteria will encourage your plant to produce its own natural IAA in order to quickly form roots.
4) Put the cutting into the rooting medium, which you have placed in a propagation tray with holes. Whether you have chosen Grodan rockwool, Oasis horticubes, iHort plugs or perlite, you will want to have it moistened (and at the right pH for Grodan) ahead of time. Fully wet the medium and allow to drain excess water. Gently press the cutting into the hole so that you don't damage any stem tissue, but firmly enough so that it stands up straight.
5) At this point, you may be done, as long as you have appropriate light. Cuttings rarely desire full strength sun or intense HID. T-5 lights, such as the Sun System Sun Blaze, are a great gentle source of light for cuttings and use relatively low wattage. Keep your medium moist and consider misting your cuttings daily. After a few days you may choose to add fertilizer at a very low strength into your mist program to foliar feed your cuttings and keep them green while they are forming new roots.
6) Optional: Many plants will root faster if you keep them on a heating mat. Use a Super Sprouter Seedling Heat Mat with thermostat to keep the temperature in the upper 70's (varies between plant types but this is a general safe range for most plants). You may also add a propagation dome with vents. Keep in mind that keeping a plant too humid and too warm can lead to damping off or other fungal issues. I often use a humidity dome but prop one side up with a pencil so that there is constant air exchange, yet humidity is kept higher than outside the dome.
Depending on all conditions and what type of plant you've chosen, expect to begin seeing roots in 6 to 10 days. Some plants, such as shrubs and trees, will likely take longer. Be patient, they will come! If you start to see a little ball forming at the base of the cutting that looks a little like a gnarl on a tree, this is a great sign! This is called the callus, and is the meristem from which the roots develop. Just remember, keep them moist and give decent airflow. Once you begin to see roots, I recommend using General Hydroponics Rapid Start to see explosive growth. They combine amino acids with a proprietary blend of plant extracts that includes willow (which provides a natural rooting hormone), to induce rapid root formation including fine root hairs.
Remember, every plant has its very own set of needs and you may need to experiment a little to get your rooting conditions just right for your favorite plant. When working with a difficult plant, consider altering the type of rooting product used, rooting medium, temperature and humidity conditions. Change one thing at a time and eventually you'll find just the right combination for your plant.
Once you've developed your skills with stem cuttings, consider trying cuttings from leaves, or roots, or take it to the really advanced level of tissue culture. You'll find it very rewarding to replicate your favorite plants over and over.