Home Propagation of Plants: Division And Layering

CROWN DIVISION
One simple and reliable method for propagating plants at home is crown division. As a general rule, plants that flower in the spring and early summer should be divided in late summer or fall. Those flowering in the summer and fall should be divided in early spring before new growth begins.

For crown division of herbaceous plants, such as irises, the clumps should be carefully lifted and some soil removed from the roots. The crown may then be cut into sections with a knife or other sharp tool. Individual shoots that contain roots may be used to form new plants, or if a larger plant is desired, several shoots may be left together. In large, old crowns, it is often best to discard the older, center portions and replant the young, more vigorous shoots that have developed on the edges of the clump.

Table 1: Some common perennials suitable for division

Plant Division Time Plant Division Time Plant Division Time
Aster (hardy) Spring Hosta (plantain lily) Spring or fall Phlox Spring
Baptisia (false indigo) Spring or fall Iris (bulbous (Dutch) Late summer, fall Primula Summer
Bleeding heart Late summer, early spring Iris, rhizomatous (German) July, August Red-hot poker (Kniphofia) Spring
Chrysanthemum Spring Iris, fibrous (Japanese) July, August Rudbeckia Spring or fall
Columbine March Lily Fall Sedum (stonecrop) Spring, July, August
Coneflower (Echinacea) Spring or fall Lily of the valley Fall Sempervivum (houseleek) Spring, summer
Coreopsis Spring Loosestrife (Lythrum) Spring Shasta daisy Spring
Daylily Late summer, spring Oriental poppy July, August Vinca (myrtle) Early spring
Delphinium Early spring Pampas grass Spring Yarrow (Achillea) Early spring
Ferns Early spring Peony Early fall Yucca Spring or fall

LAYERING
Layering is a useful and desirable method to root a new plant while the stem is still attached to the parent plant. The new plant receives nutrients and water from the parent plant until roots develop. This method of asexual propagation yields a large plant in a relatively short time and is an excellent way to produce a small number of plants in the home landscape. Layering outdoors is best performed during spring and summer months, although it can be done during any season of the year.

Healthy, maturing branches that are vigorously growing in light should be chosen for layering since they usually have more food reserves (carbohydrates) and therefore root faster. Branches from pencil size to about ¾ inch in diameter are best for layering.

Layering can be done without any special equipment or structures. Some layering techniques include simple, tip, serpentine, and air. Simple layering involves pegging down a suitable shoot into the soil. Serpentine and tip layering are similar to simple layering with flexible shoots buried in the ground. Air layering is used for plants that will not bend down to the ground. I will not go into dropping or stooling. Dropping is used for dwarf shrubs such as rhododendrons and some dwarf conifers where the whole plant is buried with only the tips of shoots exposed above ground. Stooling is a specialized technique used for some ornamental shrubs like Cornus spp. (dogwood) and Salix spp. (willow) where the soil is mounded above an existing plant to create new shoots on the buried stems.

Simple Layering
For the home gardener, simple layering may be performed whenever a plant has a branch low enough to be pulled down to the ground. It is a slow method and can take more than a year before you can separate the new plant from its parent. Simple layering is usually done in the spring when the sap is rising although it can be done from late autumn to early spring.

Many plants root when a leaf node of the shoot is buried several inches deep in the soil and the tip protrudes vertically from the soil. It is generally beneficial to wound or cut the stem at the point where it curves upward. The wounding tells the plant to send healing hormones to the cut surface. Make a slanted cut about 2 inches long either above or below the bend. Make the cut about 12 inches from the tip and dust it with a rooting hormone. Place the prepared branch or stem (A) into a hole or trench 4-6 inches deep and fasten it down to the ground with a wire peg (B). Bent U-shaped coat hangers work well. If the branch is stiff, insert a stake next to the shoot to hold the tip in an upright position (C). Fill the hole or trench and mound the soil slightly so the wounded portion of the stem will be 4-6 inches below the soil. Firm the soil.

Keep the soil around the layer moist at all times and cover with a 3”-4” layer of mulch. The layer may form roots during the first season but should not be cut form the parent plant until the following year. Some hard to root types may take two years to produce roots.

After the layer is well rooted, sever the branch where it enters the soil. Don’t disturb the roots of the layered plant for 2-6 months after it has been severed. This will allow the new plant time to grow independently. When the new plant is dormant, it can then be transplanted to a convenient protected spot or container where it can be tended carefully for one year before moving it to a permanent location.

Serpentine Layering
Serpentine layering is suitable for long vines and requires that the shoot be alternately covered and exposed. The technique is simple layering in
multiples. Wounds should be made on the lower portion of each curve between leaf nodes. Bend the shoot down so that each wounded area is in

the bottom of a hole and the shoot between is still above ground. Peg them in place as done with simple layering. Do not layer the tip of the shoot or this will root and the other layered sections behind it will rot. This method is suitable for vines such as honeysuckle, clematis, or wisteria. The branch is cut into segments after rooting has taken place.

Tip Layering
Tip layering on raspberries and blackberries is easy to do in the spring. It consists of rooting tips of the current season’s growth. The tip of the shoot is where the strongest concentration of rooting hormones is. Rooting can be stimulated in late summer as the drooping canes develop an elongated appearance and leaves become smaller. Pull the tip of these shoots down and insert them in holes 4-6 inches deep. Peg the tip down with U-shaped pieces of wire and fill the hole with free-draining soil. Rooting generally takes place rapidly and the plants may be transplanted later the same season. Survival is better if transplanting is delayed until just before growth starts in the following spring.

To stimulate more tips, pinch out the top 3-4 inches of a 2-foot tall cane in the spring. By late August or early September, the new growth will arch
down, touch the soil and turn upward. These often root without assistance at the point of the curve where they touch the soil.

Care after rooting layered plants: The root system of newly rooted layers is small in relation to the tops. As soon as the layer forms new roots, cut it from the parent plant and transplant it to a container. Prune the stems so that the leaf area is reduced to at least one-third. The new plants should be located in a lightly shaded area. Suitable shading may be made from an old window screen. After the first winter, the screen can be removed. Sufficient roots should have developed so that the plants can be moved to a permanent location.

Air Layering
Air layering is a useful method for rooting difficult to root plants, which include magnolia, witch hazel, gardenia, rose, fig, holly, camellia, azalea, and many of the fruit and nut bearing plants such as apple, pear, and pecan. The procedure is to wound the stem or branch of the plant and enclose the wounded stem with moist sphagnum moss until roots develop from the wounded area. For optimum rooting, make the air layers in the spring on shoots produced from the previous season’s growth or in midsummer on mature shoots from the current season’s growth. On woody plants, stems that are pencil size or up to ¾ inch diameter are best. The stem may be much thicker on the more herbaceous plants.

First remove leaves and twigs on the selected limb for 3-4 inches above and below the point where the air layer is to be made. The air layer is usually made 12-15 inches below the tip of the branch. The branch is wounded to induce rooting. The method of wounding woody plants such as magnolia, rose, and similar plants is to make two parallel cuts with a shape knife about 1-1/2 inches apart around the stem and through the bark and cambium layer. If the cambium layer is not removed, new bark will form instead of roots. Connect the two parallel cuts with one long cut and remove the ring of bark, leaving the inner woody tissue exposed. You may want to cover the cut nearest the tip with rooting hormone although this is seldom necessary.

Apply a handful of damp sphagnum moss so that it envelops the wounded portion of the stem. It may be necessary to wrap kitchen string around the moss to hold it in place. The sphagnum moss should be soaked several hours before using to ensure that it is thoroughly moist. Squeeze out the excess moisture, as it will result in decay of the plant tissue.

Use a sheet of polyethylene film (plastic wrap works well) about 6 inches by 12 inches to wrap around the ball of sphagnum moss. Be sure there is a good seal all around. Make sure the upper end of the film fits snugly around the stem and none of the moss is exposed. Fasten securely with twist ties but not so tight as to bite into the stem. This will allow you to open the plastic wrap to check for rooting without disturbing the new roots. You may use electrician tape instead of twist ties but take care that the tape extends beyond the film and adheres to the stem. Repeat the procedure on the lower end, making sure there is a snug fit. Moisture should not be allowed to escape from or leak into the wounded area. If necessary, support the plant with a stake or splint to prevent breakage at the wounded area. Wrap with aluminum foil large enough to completely cover the plastic wrap and extend up and down the branch a couple of inches in either direction. This will prevent heat buildup under the plastic. Crimp the foil for a good seal.

The rooting time will vary with each plant variety as well as the season in which it is performed. In 6 weeks to a year or so, you should have a new plant. If no roots are visible in the moss ball, carefully remove the plastic and moss to check the cut area. If the wound is still moist and has a swollen callus tissue at the top, then the roots should appear soon. Replace the packing with new moist moss, plastic, and aluminum foil. If the stem has healed over the wound, start again with a different shoot.

After the new roots have penetrated the moss ball and are visible on all sides, the rooted branch may be removed from the parent plant. Remove the newly rooted plant from the parent plant with a sharp knife or pruning shears, making the cut just below the ball of moss and roots. Carefully remove the aluminum foil and plastic wrap. Plant the root ball of moss in a container using a good potting mixture. Be very careful when you firm the dirt around the new plant since the new roots are easily broken off. The potted plant may be placed in a cold frame in a lightly shaded area to allow for the establishment of roots and to harden off the new plant. Keep it in a sheltered area for at least 4-6 weeks before you move them into stronger light. The plants will let you know when they are ready for more light by sending out new growth.

If you don’t have a cold frame, you can accomplish the hardening off process by placing a polyethylene tent over the newly potted plant for about 2 weeks to prevent moisture loss. Keep the plant in light shade and avoid direct sunlight until the new root system is well developed. Harden off the plant gradually by cutting a few holes in the plastic tent to reduce the humidity until it reaches the surrounding environmental conditions.

The University of Florida’s Landscape Plant Propagation Information (LPPI) website, http://hort.ifas.ufl.edu/lppi/htm, contains a lot of information on propagating many different plants.

Table 2. Some Common Plants Suitable for Layering

PLANT LAYERING TIME LAYERING METHOD ROOTING TIME
Akebia spp. Early spring to early autumn Serpentine 12-18 months
Azalea spp. Early to late winter Simple 9-12 months
Azalea spp. Early to mid-spring Air 12-18 months
Buxus spp. Early to mid-spring Dropping 6-9 months
Camellia spp. Later winter to early spring Simple 6-12 months
Campsis radicans Mid-to late autumn Simple, Serpentine 9-12 months
Clematis spp. Mid-to late autumn Simple, Serpentine 9-12 months
Daphne spp. Early to midsummer Simple 6-9 months
Euonymus spp. Early to mid-spring Simple 6-12 months
Ficus elastica (rubber plant) Mid-spring to late summer Air 6-9 months
Forsythia spp. Spring to late spring Simple 6-9 months
Fothergilla spp. Late summer to early autumn Simple 12-18 months
Hamamelis spp. (witch hazel) Early to mid-spring Air 12-18 months
Ilex spp. Late summer to autumn Air 12-18 months
Ilex spp. Early to mid-spring Simple 9-12 months
Jasminum spp. Early to mid-spring Simple 6-9 months
Magnolia spp. Early to mid-spring Simple 12-18 months
Magnolia spp. Mid-spring to late summer Air 18-24 months
Rhododendron spp. Early to mid-spring Simple 12-18 months
Rubus spp. (blackberry, etc.) Early spring to midsummer Tip 3-6 months
Viburnum spp. Early to mid-spring Simple 9-12 months
Vitis spp. Early to late winter Simple, Serpentine 9-12 months
Wisteria spp. Early to mid-spring Simple, Serpentine 12-18 months

Scented Geraniums: A Worthy Addition To The Home Garden

Scented geraniums (Pelargonium species) are excellent herbs to grow in the garden. They are tender perennials and are planted in containers so that they can be easily brought in for the winter. These plants are treated as annuals, but have been known to survive the winter if mulched and the temperatures do not get too cold. They are grown for their scented leaves, not for their flowers like traditional geraniums. Scented geraniums come in all shapes, sizes, and colors. Some have highly aromatic foliage. Some varieties have bright red flowers, while others vary from white to pink. Their leaves range from rounded to finely cut. The leaves can be dried and used in potpourris or added to teas.

They should be grown in well-drained soil and in full sun. However, during the hot part of the day, they need some shade to keep from being scorched. The smaller leafed varieties have a tendency to become “leggy.” Consistent pruning will encourage a more dense growth. It is best to pinch them back with your fingers to remove the stem tips above a leaf. Leave several leaves on the stalk because the plants will branch out from here.  They are light feeders and only occasionally need a dose of all-purpose fertilizer like 10-10-10.

Cuttings can be rooted in a glass of water but do better when rooted in a soil-less growing media like sand or vermiculite. Take six-inch cuttings, strip of the lower leaves, and dip into rooting hormone. Keep the rooting medium damp. After a few weeks, gently tug on the plants. If there is resistance, then they have formed roots and can be transplanted to a growing medium.

There are a multitude of scented geraniums available. They are categorized by aroma, such as rose, mint, fruit, spice, and other pungent fragrances. The scented geranium can smell like rose or lemon, or the plant may give off a scent of cloves or nutmeg. It may have the odor of pine or peppermint; apple or apricot; or chocolate or coconut. One of the most commonly grown cultivars is ‘Attar of Roses.’ Rubbing the leaves together of this old-fashioned scented geranium will reward with the fragrance of roses.

Caring for Your Garden Tools

Now that your fall garden chores are completed, it’s time to give your trusty garden tools some attention before storing them. By properly cleaning and making the necessary repairs now, your tools will be less apt to corrode. When spring rolls around, they will be ready to be used.

Wooden Handles:To clean the handles, wipe them with a dry cloth. Use little, if any, water. Fine sand paper can be used to smooth the surface. Remove the sanding dust, rub linseed oil into the handle and let it soak in. Continue this process until it doesn’t absorb any more oil. Wait about half an hour and dry any oil that remains on the surface. This will help prevent drying out and splintering. Another option is after cleaning and sanding the handle, coat it with neon colored oil-based paint. It’s a lot easier to find that misplaced trowel when the handle is painted neon yellow or orange.

Metal Surfaces:
Clean as much dirt as you can from your shovels, hoes, and other digging tools. Then shove them into a large bucket containing about 5 pounds of builder’s sand mixed with one quart of motor or vegetable oil. Work the metal end of the tool up and down in the sand a few times and then wipe off the excess oil. The sand cleans the metal and the oil coats it to prevent rust. You can also store your tools in the sand mixture for the winter. Keep a smaller bucket of this mixture handy for whenever you use your tools during gardening months. For garden tools that are really rusty, soak them in white vinegar and use steel wool or a wire brush to remove the rust. Once the rust is removed and the surface is clean and dry, apply a rust-proofing primer.

Pruning Tools:
Wipe the metal parts of pruners, shears and loppers with an oily rag. WD-40 oil is a good choice. File the cutting edge to keep the tool’s blade sharp. File away from you at the same angle as the original bevel using long even strokes. Then, file the opposite side lightly to remove any burrs for a clean, sharp edge. Be sure to wear your safety glasses when working with files or power tools. If this isn’t in your comfort zone, have a professional sharpen your tools.

Lawn Mower and Tiller:
Drain the gasoline from the fuel tank or add a stabilizer to a full tank of gas and run the equipment for a few minutes to be sure all the internal parts of the engine are coated. If the equipment has a separate oil reservoir, change the oil. Replace any air and oil filters. Check the spark plug and clean or replace it. Tighten all bolts. Remove all the matted grass on top of, underneath or around the blades. Have your mower’s blade sharpened.

Caring For Your Holiday Plants

With the holidays rapidly approaching, it is a great time to give the gift of a blooming plant that can be used to decorate the home. Here are some tips to keep your plant healthy, happy and ready to bloom.

Christmas cactus and Amaryllis are plants native to Central and South America while Poinsettia comes from Mexico. Since these are all tropical plants, they share a lot of basic “do’s and don’ts.”

  • Do keep plants in windows with bright, indirect lighting.
  • Do provide room temperatures between 65-70°. If you’re comfortable, so is the plant. Cool temperatures will help it keep the blossoms longer.
  • Do water when the top 1” of soil feels dry to the touch, but don’t let your plant sit in standing water.
  • Do fertilize with a balanced, all-purpose liquid fertilizer only after your plant has finished blooming.
  • Don’t place your plant near cold drafts or excessive heat. If you’re going to transport the plants, place them in a large shopping bag or box to protect them from the cold.

CHRISTMAS CACTUS (Schlumbergera bridgesii): Known as epiphytes (a plant that grows on another plant), the Christmas cactus is found growing on decayed leaves and debris in the forks of tree limbs the same way orchids grow. [Ed. Note: There is also the Easter cactus (S. gaertneri) and the Thanksgiving cactus (S. truncata)].

These plants love humidity so a good idea is to put gravel in the pot’s saucer. Excess water will drain into the gravel and give your cactus the moisture it loves.

Feed your cactus with a 0-10-10 liquid fertilizer in February when it has finished blooming. From April through September you can use a liquid 10-10-10 monthly. In late October or early November, feed it once more with the liquid 0-10-10.

When summer arrives, you may want to move your cactus outdoors. If you do, keep it in a partial to total shade location. Too much direct sunlight can burn the leaves. To propagate and encourage your plant to branch out, prune it after blooming. Remove a few sections from each stem by finger pinching or cutting with a knife and root these sections in moist vermiculite or sand. Once rooted, transplant to a potting mixture for succulents or combine two parts potting soil with one part sand or vermiculite.

Christmas Cactus Reblooming Tips: About September 1st bring your plant back indoors and keep the room temperature around 50°F. Place it where it will receive bright, indirect light during the daylight hours and total darkness at night. During the fall and winter months, water it less frequently to promote blooming.

Problem Note: Buds dropping off of your plant can be the result of over-watering, insufficient light, or lack of humidity.

AMARYLLIS (Hippeastrum spp.):

If you’ve received this wonderful bulb that was not potted, soak the roots of the bulb in lukewarm water for an hour. Plant the bulbs in a  well-drained potting mix with the soil up to the base of the bulb’s neck and firm the soil to set the bulb in place. The potted bulb needs to be placed in warm location with direct light to encourage stem development. The warmer the temperature (70-80°), the faster it will sprout and grow. Water it sparing until the bud and leaves appear; then gradually increase the amount of water it receives. Be sure to rotate the pot so the plant will grow straight. A south facing window provides ample sunshine to help the stem’s rapid growth. As soon as it reaches its full height,
flowers will develop.

To keep the plant looking its best, pinch off any blossoms that start to droop or wither. After flowering, cut off the stalks so that only 2”-4” remain. Put the pot in a warm, sunny spot and continue to water when the soil feels dry. You can move your amaryllis outdoors in full or partial sun when the temperature in spring has warmed up. A monthly liquid fertilizer 10-10-10 is recommended for the next 5-6 months.

Amaryllis Reblooming Tips: As cold weather approaches, stop watering and feeding your plant to force it into dormancy. Remove any foliage that turns yellow or is dead. Before the first frost, bring your potted plant indoors and keep it in a cool (50-60°), dry, dark place like your basement. Or you can remove the bulb from the pot, clean off the dirt, and separate any bulblets from the mother bulb. Place all of these in the crisper of the refrigerator for a minimum of 6 weeks.

Problem Note: Don’t store the bulbs in the refrigerator with apples since this will make the bulbs sterile. In November, pot the refrigerated bulbs or remove the potted plant from the basement. Resume your normal care of watering and feeding. There’s a chance your amaryllis won’t bloom the first year, but don’t despair. Give it a second chance.

POINSETTIA (Euphorbia pulcherrima):
Our first Ambassador to Mexico, Joel Robert Poinsett, brought these Mexican beauties to the US in 1825. What look like flowers are actually colorful modified leaves (bracts). The true flower is a small green or yellow nub in the center of the bracts.

These plants definitely won’t tolerate moisture extremes. Too wet and you’ll get root rot. Too dry and it will wilt and drop its leaves. In early April, cut your poinsettia back to 6”-8” in height and place it outdoors in the shade. When new growth appears, keep it watered and fertilized. If you need to transplant your poinsettia to a larger pot, do it in May. Pinch off the growing tips every 4-6 weeks during the summer to make your  plant bushy. Do not prune after September 1. Bring your poinsettia indoors before the threat of cold weather.

Poinsettia Reblooming Tips: This can be really tricky and challenging. Beginning around October 1st, place your plant each day in complete darkness from about 5 PM to 8 AM. Do not expose it to even a single burst of light during these dark, nighttime periods. During the daylight hours, place it where it will receive bright, indirect sunlight. By December, you’ll be rewarded with lovely, colorful bracts.