How to Propagate Evergreen Trees: A Simple Guide for Beginners

Plants can be propagated, or multiplied, in several different ways. Most people are familiar with growing new plants from seeds, but new plants can also be created by cutting off a portion of an established plant. This “cutting” is placed in an environment that encourages it to produce new roots and/or stems, thus forming a new, independent plant.

Cuttings can be made from any part of the plant. Most frequently, however, either a stem or leaf is used. A stem cutting includes a piece of stem plus any attached leaves or buds. Thus, the stem cutting only needs to form new roots to be a complete, independent plant. A leaf cutting uses just the leaf, so both new roots and new stems must be formed to create a new plant.

Stem cuttings can be taken from both herbaceous plants (e.g., garden flowers and houseplants) and woody trees and shrubs. Because the new growth of trees and shrubs hardens as the summer progresses, cuttings taken at different times of the year vary in their ability to form roots. Softwood and herbaceous cuttings are the most likely to develop roots and become independent plants, hardwood cuttings the least likely.

Softwood cuttings are prepared from soft, succulent new growth of woody plants just as it begins to harden (typically May through July). Shoots at the softwood stage will snap easily when bent. The youngest leaves have not yet reached their mature size.

Semi-hardwood cuttings are taken from the current season’s growth after the wood has matured. The wood is firm and all leaves are full size. This occurs in mid-July to early fall for most plants. Many broadleaf evergreens (e.g., boxwood, holly, rhododendron) can be propagated by semi-hardwood cuttings.

Hardwood cuttings are prepared from shoots that grew the previous summer. They are cut in winter or early spring while the plant is still dormant. The wood is firm and does not bend easily. Some deciduous shrubs and needled evergreens will root from hardwood cuttings.

Leaf cuttings are prepared by taking a single leaf from the plant. This leaf must generate not only new roots, but new shoots as well. The leaf used for propagation usually does not become part of the new plant, but disintegrates after the new plant is formed. Only a limited number of plants have the ability to produce new roots and shoots from just a leaf.

Cuttings taken from roots may also be used but only a few species can be propagated this way. Cuttings are taken when the plant is dormant and the roots contain the most stored energy. Each root produces two to three new stems and each stem then produces its own roots. The original root cutting disintegrates.

To successfully propagate plants from cuttings, a number of challenges must be overcome. Once a cutting is severed from the parent plant, it can no longer take up water, and excessive water loss will result in death. The wound from the cut makes it susceptible to diseases. New roots must be formed as rapidly as possible if the new plant is to survive.

Start with cuttings that contain as much water as possible. Water the plant well the day before and take the cutting before the heat of the day reduces water content.

1. Process the cutting immediately. If this is not possible, stand the cut end in water or place the cutting in a plastic bag with a damp paper towel and store out of direct sun. If the plant is frost-tolerant, store the bagged cutting in the refrigerator.

2. For a stem cutting, remove some of the leaves. Most of the water will be lost through the leaves, so by decreasing the leaf surface you also decrease the amount of water loss. A general rule of thumb is to remove 1/2 to 2/3 of the leaves. Cut remaining leaves in half if they are large.

3. Once the cutting has been prepared and placed in the rooting mix, enclose the pot in a plastic bag. Insert straws or wooden sticks around the edge of the pot to hold the bag away from the cutting. Place the pot in a bright area, but out of direct sunlight, so the leaves will receive the light they need but the plant will not get overly hot. The plastic bag insures that humidity around the leaves remains high, which slows the rate of water loss.

Take cuttings only from healthy plants. To prevent the spread of disease, use clean tools and pots (clean with 10% bleach, rinse, and let dry thoroughly). Use fresh soilless potting mix since garden soil can harbor plant diseases.

Just like leaves, the roots of plants need air to live. Rooting mix that is continuously waterlogged is devoid of air and cuttings will rot rather than form roots. A mixture of 50% vermiculite/50% perlite holds sufficient air and water to support good root growth, but any well-drained soilless potting mix is acceptable. If your cuttings frequently rot before they root, you know the mix is staying too wet. Add vermiculite or perlite to increase its air- holding capacity.

Cuttings use energy to form new roots. If the cutting has leaves, most of the energy comes from photosynthesis. Expose these cuttings to bright light, but not direct sunlight, during the rooting period. If you use hardwood cuttings that have no leaves, the energy will come from reserves stored in the woody stem. For best results, select shoots that are robust for the species. Since you want all the energy to go into the new roots, make sure you cut off any flowers or fruits that would compete for energy.

Auxin, a naturally occurring plant hormone, stimulates root formation. Several synthetic forms of auxin are sold as “rooting hormone.” Though some plants will root readily without treatment, application of rooting hormone to the base of the cutting will often improve your chance for success. Two synthetic auxins, IBA (indolebutyric acid) and NAA (naphthaleneacetic acid) are most frequently used. They are available in several concentrations and in both liquid and powder form. 1,000 ppm (0.1%) is used most often for herbaceous and softwood cuttings; 3,000 ppm (0.3%) and 8,000 ppm (0.8%) are used for semi-hardwood and hardwood cuttings. Liquid formulations can be used at low or high concentration for softwood or hardwood cuttings, respectively. To determine the appropriate concentration for your cutting, follow the instructions on the product label and the general guidelines just given, or consult the references listed at the end of this publication.

To use rooting hormone, place the amount needed in a separate container. Any material that remains after treating the cuttings should be discarded, not returned to the original container. These precautions will prevent contamination of the entire bottle of rooting hormone.

Cuttings will root more quickly and reliably in warm rooting mix. Keep your cuttings between 65°F and 75°F, avoiding excessive heat. If your area is too cold, consider a heating mat or cable especially designed for this purpose.

Preparing Needled Evergreen Cuttings

Needled evergreens are often propagated as hardwood cuttings. Because they still have leaves (needles), these cuttings are handled in a different manner than hardwood cuttings of deciduous plants.

• Use shoot tips only, making the cutting 6-8 inches long.
• Remove the needles from the bottom 3-4 inches of the cutting. To reduce water loss, trim the remaining needles so that they just cover the palm of your hand (Figure 7).
• Wound the base of the cutting by drawing a knife point down the lower inch of stem on two sides (Figure 8). Cut into the stem but do not split it. Apply rooting hormone to the lower inch of the stem and place about 2 inches of the stem into the rooting mix, making sure that no needles touch the surface of the mix. Firm the mix around it.

The potted cuttings may be placed in an unheated area with a heating element to warm the rooting mix if the area is well lit. If not, cover the pot and cuttings with a plastic bag and place in a warm, brightly lit room, as with deciduous hardwood cuttings. Providing light is essential for successful rooting of these cuttings. Check for roots once a month. It may take three or four months for roots to develop. Acclimate rooted cuttings as described above.

How to Make Specialized Stem Cuttings

Some houseplants can be propagated most easily using these variations of stem cuttings.

Cane cuttings are used for Dieffenbachia, Dracaena (including corn plant), and other plants with thick stems. The stem, or cane, is cut into segments and placed into rooting mix. New shoots emerge from the buds that are on the cane; roots grow from the portion of the cane in the rooting mix (Figure 9). The initial absence of leaves reduces water loss.

• Cut the cane into segments that contain several buds (usually 2-3 inches in length).
• Select a healthy bud and place the cane horizontally into the rooting mix so that this bud points up and only the bottom half of the cane is in the rooting mix. The portion of the cane placed in the rooting mix may be treated with rooting hormone.
• Alternately, the end of the cane closest to the base of the plant can be treated with rooting hormone. The cutting is then placed into the rooting mix vertically, about 1/2-inch deep (Figure 10).

Leaf-bud cuttings use just a small portion of the stem (up to 1 1/2 inches) that contains a single bud and single leaf. The stem portion produces roots, and a new shoot develops from the bud (Figure 11). Treat the stem with rooting hormone, then place in rooting mix so that the bud is below the surface and the leaf is exposed to light. This method is used with grape ivy, geranium, philodendron, English ivy, and the fleshy-leaved peperomias.

Since both types of specialized stem cuttings will lose water easily, place the pot in a plastic bag until roots form.

How to propagate evergreen trees from limb unions and cuttings.

FAQ

Can you root evergreen cuttings in water?

Chinese Evergreen propagation is possible through the following 3 techniques: in soil, in water (both from stem cuttings), and by division (using the offsets).

Can you grow pine trees from cuttings?