When it comes to gardening and plant propagation, we usually talk about propagating by planting seed. However, there are several other types of propagation that we can use to continue specific plant varieties. They include stem cuttings, root cuttings, divisions, bulb separation, and layering (which includes simple layering, tip layering, compound layering, mound [stool] layering, and air layering). We will cover each of these so that you can try your hand at them with the plants in your gardens. This edition will contain seed propagation and the different cutting methods. In part two, we will go through the various layering methods.
Seed propagation (or “sexual propagation”) is the most frequently used method of producing new plants. It offers several advantages over the other methods: It is economical, it transmits fewer diseases, seeds are inexpensive to purchase and store for long periods of time, and little personal effort is needed.
Disadvantages of Seed Propagation
Many seeds require a long time to germinate or special pretreatment to overcome internal dormancy. For example, some seeds require physical abrasion or fermentation before germination can occur. Another problem that may occur from seed propagation is genetic variation. Seed companies go to great lengths to develop plant cultivars that are uniform in color. When they develop hybrids, the work even harder to make sure the crosses will breed true each time. Hybrid seeds you purchase are the first generation of their parental crosses. If you save seed from hybrid plants to sow the next season, the results may be a genetic scramble, which may produce an array of sizes, shapes, and colors.
Successful Seed Propagation
Start with good, clean, fresh seed. Be picky about the medium you choose for germinating your seed: It should allow for good air circulation and plenty of water to reach the seeds. Soil from your garden is a poor choice. Milled sphagnum moss is an excellent choice as it is highly acidic and will eliminate weeds, insects, and diseases. However, it may not be readily available for gardeners in all areas. Other mediums to use are perlite, vermiculite, peat moss, or commercial mixes like Jiffy Mix.
The containers for your seedlings should be clean, inexpensive, and readily available. Old milk cartons cut in half can be used, as can paper egg carton bottoms, old butter tubs, and/or reused salad trays from fast food restaurants. The choice is yours—just be sure they are thoroughly cleaned before use.
Fill containers to the top with your choice of medium. Push the “soil” down so that it is half an inch from the top of the container and score off some shallow rows for planting your seeds.
Remember not to plant your seeds too deep. When in doubt, plant them shallower than you think necessary. In the absence of package instructions, remember to plant your seeds ¼ to ½ inch apart with your rows about two inches apart. All of these specifics are to reduce incidence of disease, especially the fungus that causes damping-off (a disease which will girdle and kill seedlings).
Great care while watering will also lessen the onset of diseases. Water well through drainage holes in the bottom of your containers. When soil is well watered, set containers over another container to drain out excess water, then set the container inside a clear, plastic bag.
When the first true leaves appear, most seedlings are ready to transplant. Make a hole in the new container – either a pot or a flat – large enough to hold the seedling’s roots. Place the new plant into the hole and gently but firmly pack the soil around the plant. Set your containers an area with the lighting required by the new plants. Plants that are to be moved outside should be transitioned slowly; begin acclimating plants with thirty minutes of sunshine daily and build up to a full day in a protected area, a night in an unheated porch, and watering less frequently. These steps should begin ten to fourteen days prior to the actual move out date. Be cautious of your tender plants: a brush with near-freezing conditions may set them back or even kill them. Other hardier plants can tolerate occasional brief exposures to cold without visible harm.
God did an amazing thing when He spoke plant life into being. He gave each cell in a plant the ability to duplicate all of its parts and functions. By taking a cutting from a leaf or stem and employing the proper conditions, you can grow a whole new plant.
This is the most popular method for propagating woody shrubs and ornamental plants, as well as your favorite houseplants. Find a healthy stem that has no flower buds, diseases, or insects. Using a clean, sharp knife, make a clean cut at a forty-five degree angle; this will maximize the area for roots to grow. Cuttings should be three to six inches tall – shorter for smaller plants – and should include the stem’s tip and at least two to three sets of leaves. Remove the lower set of leaves and dip the bottom into a bit of rooting hormones. This will seal the cut tissue and promote new root growth. Place your cuttings into the same type of medium that was used for planting your seeds. Poke holes into the medium to receive your cuttings rather than just jabbing them in, as this will keep the root hormone from wiping off. Place in a light and airy environment. It may also be beneficial to place the tray of cuttings in a plastic bag to maintain humidity while they root. Keep the plastic from touching the plants. Clear glass or plastic jars may also be used. (If you don’t want to use rooting hormone, cuttings can also be placed in a vase of water until their roots develop.)
Once roots have developed, replant in another container with moist – not wet – soil. One way to tell if roots have developed is to gently pull on the stem of your cuttings; if they pop out easily, they are not ready. However, if you feel resistance, they are ready to repot. Until fully established, monitor the amount of moisture and light they receive. Remove dropped leaves and diseased plants quickly to keep fungi from spreading to healthy plants.
Several herbaceous or woody plants can be propagated from leaf cuttings. In this method, a leaf and its petiole (or stem) – sometimes even just a part of the leaf – can be used to create a brand-new plant. Directions for leaf cuttings are the same for softwood and hardwood stem cuttings and can be done anytime of the year. Choose a healthy, full-grown leaf from a vigorously growing plant. Carefully remove it and a section of its stem (roughly two inches long). Dip the bottom into root hormone and plant the whole stem, to the bottom of the leaf, at an angle in a moist rooting medium. Water thoroughly to settle the potting mix around the plant. Place the pot in a plastic bag to increase humidity and keep in a cool place out of direct sunlight. New roots will be formed four to six weeks after planting, and the plant can then be moved into a larger container.
*Note: Sometimes more than one plant can be grown from a single leaf cutting. About six weeks after planting the cutting, you can carefully separate them and transplant into individual containers.
These are best taken when the plant is in its dormant state and the roots are full of carbohydrates. With a clean knife, take one to four-inch cuttings from younger root growth that is ¼ to ½ inch thick. Cut straight through the end of the root nearest to the stem and cut the other end at an angle; this will allow you to remember which end is the top (the straight cut) and which one is the bottom (the angular cut). Roots will not grow if you plant them upside down. Store your cuttings in a moist rooting medium at about 40° F. In three weeks, remove cuttings from storage and bury them under two to three inches of soilless potting medium. Place the containers in plastic bags and place in an area that is bright with indirect sunlight. When roots are established and weather permits, harden off new plants, then transplant them into your garden where they will best thrive.
*Note: If your root cuttings are from small or fine roots, scatter them over the surface of your moist, soilless potting medium and cover them lightly. Proceed as above for transplanting and care.
You can learn more about handling plants and transplanting them at: