Introduction
Have you ever loved a plant so much that you wished you could make more plants just like it? Well with propagation you can do just that! It is a great way to save money, preserve heirloom varieties, and keep a succession of plants growing throughout the year.
What is Plant Propagation?
Propagation is simply the process of creating new plants. Some plants naturally propagate themselves. Think about plants like strawberries, potatoes, and ginger. These plants send out runners, tubers, or rhizomes that create individual plants. These new plants can be separated from the original and transplanted elsewhere or kept together as a group. Other plants do not propagate naturally, but can be propagated through artificial means or human intervention. Herbs, tomatoes, figs, grapes, even certain flowers can be propagated to create new plants. There are two main methods of propagation which are sexual propagation, from seed, and asexual propagation, from vegetation. Let’s talk about the differences.
Different Methods of Plant Propagation
Sexual Propagation (Seed Propagation)
Sexual propagation or seed propagation involves growing plants from seed. This might not be what you typically think of when you think of the word “propagation”, but by definition it is. Certain plants cannot be propagated any other way. Think of a carrot for example, you can replant a carrot top and it will grow new greens but it will never grow a new carrot root. Therefore seed propagation is the only way to make more carrots.
Seed propagation can also give rise to hybrids and new plant varieties through cross-pollination that we would otherwise never see. Along the same lines, this type of propagation creates genetic variation which allows plants to adapt to ever-changing environmental conditions. Check out our video on seed saving to learn our tips and tricks.
Asexual Propagation (Vegetative Propagation)
Asexual propagation or vegetative propagation involves producing identical clones of parent plants.
Stem Cuttings
Stem cuttings create a clone of the parent plant and is most often what we think of when we think about propagation. This type of propagation is especially useful for hybrid plants. If you watched the video linked in the seed propagation section above, you would already know this, but you should not be saving seeds from your hybrid plants. They are unpredictable and can revert back to one of the parent plant characteristics, or create their own altogether, so stem cuttings are one of the only ways to get the same characteristics again and again.
Many plants can be propagated using this method from soft stemmed plants, like herbs and flowers, to more woody plants and even trees. We have successfully propagated tomatoes, coleus, citronella, geraniums, figs, and rosemary using this method.
Begin by taking the cutting from a stem of the plant with 2 or more nodes. Remove the lower leaves from the cutting. You can apply rooting hormone at this stage, or place the cutting directly in the media or your choice. Place the cutting in a warm area, but avoid direct sunlight. Maintain humidity using a plastic bag or dome and keep the media moist. In 3-6 weeks you should see roots and once the roots are approximately 1” long, you can plant in soil!
Leaf Cuttings
Some of the best plants for leaf cuttings include succulents, begonias, and African violets. To take a leaf cutting you will first want to select a healthy leaf and remove it from the plant ensuring that the base is intact. Insert the leaf vertically in the growing medium of your choice. Succulent leaves tend to be fleshy because they store water. It is often best to allow these leaf cuttings to callus over before placing them on a planting medium. When it comes to succulents, do not water until roots start to appear. However African violets and begonias will benefit from some humidity and moisture.
Root Cuttings
Plants that produce suckers from their roots can be propagated using root cuttings. There are a number of herbaceous perennials that can be propagated using this method as well as a few woody varieties such as figs, raspberries, and blackberries. One of the main advantages of propagating using this method is that cuttings taken using this method are free from foliar pests like mealybugs, aphids, and stem/leaf nematodes. It is best to take these cuttings in the winter when the plant is completely dormant.
Lift the plant and wash the roots. Select roots that are about the thickness of a pencil and cut horizontally with a sharp knife or shears. Each cutting should be 2-4” in length with a horizontal cut at the top and an angled cut at the bottom. Prepare a pot or pots with a mixture of equal parts compost and either sand or perlite. Place the cutting vertically so that the horizontal end is just below the soil surface. The orientation of the cutting is important because it will not grow if placed in the medium upside-down. Water lightly and wait for growth to appear the following spring.
Layering
Layering is the process of propagating while the stem is still attached to the parent plant. There are a few types of laying: simple layering, tip layering, compound layering, and air layering. Some plants can create layers naturally, while others need some assistance to get the process started.
Simple layering involves bending a low lying stem to the ground and burying a section in the surrounding soil with 6-12” left above the surface. Tip layering is similar, except you bury the tip of the stem. This method works well for blackberries. Compound, also called, serpentine layering is similar to simple layering, but with multiple sections buried on one continuous stem. Compound layering works well for grapes and other vining plants. Air layering and mound layering are also forms of this type of propagation, you can read more about them in the article linked at the beginning of this section. These methods are best done in early spring or late summer.
Division
There are many perennial plants that benefit from division such as hostas and ornamental grasses. Division can help to limit competition for nutrients and stimulate new growth. If your perennials are starting to die back in the center or produce less flowers, it might be time to divide! The best time to do this is in spring or fall depending on the plant’s natural flowering cycle. Divide spring bloomers in fall and fall bloomers in spring for the best results.
To divide a plant, you will want to dig up the entire plant carefully and use your hands or a sharp knife to separate the root ball. Then plant those divisions in the desired location and make sure that the soil is well-draining and kept moist until new roots have begun to grow.
Grafting
We aren’t going to dive too deep into the idea of grafting in this article, but grafting is a method of artificial propagation that takes cuttings from one plant and attaches them to the main stem or trunk of another. This method is primarily used for plants that do not root well from their own cuttings, for disease resistance, and/or combining traits. Fruit trees and roses are the most common plant types that benefit from this propagation technique.
Essential Tools for Propagation
You likely have the majority of the tools you will need for propagation. Start with a pair of clean sharp sheers or a knife. I like to regularly wipe my shears with a rubbing alcohol soaked rag in between plants so that I do not spread pests or diseases anyways, but it is especially important when taking cuttings for propagation.
The one thing that you may not have on hand is rooting hormone. You may use this when transplanting seedlings, but otherwise this product is mostly only used for propagation. There are store bought powder and liquid varieties on the market, but did you know you can make your own? DIY rooting hormone can be made with household staples from cinnamon to Aloe Vera along with many other options, so experiment and find out which one you like best!
When it comes to trays, pots, or other containers to propagate, I say use what you have. There is a doohickey and a thingamabob for just about everything, but in this case a cup works just fine! I prefer my container to be clear so that I can see the roots develop, but again if all you have is a black nursery pot, use that.
The growing medium that you choose depends somewhat on the plant you are propagating. In general, choose a medium that is sterile and drains easily. Sand, vermiculite, or a combination of peat moss and perlite are some of the many options. My favorite growing medium for propagations is simple water. I like that I can take my cutting and put it in a clear glass or mason jar and watch as the roots begin to form!
Best Practices for Successful Propagation
When choosing which plants to propagate, you will want to consider healthy plants with preferred characteristics. Make sure to take cuttings from healthy looking stems, leaves, or roots depending on the propagation method for best success.
Overwatering and underwatering can also lead to issues with propagation. You can utilize a moisture meter for precision, or the finger test, to determine if your cutting needs more or less water.
Don’t forget about the humidity factor! Since your cuttings don’t have roots yet, maintaining high humidity is important to prevent them from drying out and to promote root development.
Conclusion
Propagation, much like all aspects of gardening, is one big experiment. I could propagate the same plant the same way that you did and have different results. Not everything is going to take root and that is okay. If one method doesn’t work for you, try another, or simply try again. It is all part of the fun. Try propagating your favorite plant and share your experience with us!
