How to Root Plant Cuttings
Rooting materials
Clean, coarse, construction-grade sand is suitable for rooting many cuttings. It is also excellent mixed with an equal volume of peat moss.
Vermiculite is a lightweight material used for rooting. It holds water well and promotes fine root growth.
Perlite is another excellent propagation material. It is lightweight and provides good aeration for rooting. Perlite makes one of the best rooting materials when mixed with an equal volume of peat moss.
Don’t use field soil as a rooting medium. It packs too tightly under wet conditions and is prone to develop diseases.
Compressed peat pellets are available for seeding and can also be used for rooting cuttings. They expand rapidly when soaked in water. Place them in plastic bags after soaking and draining; insert a single cutting in each pellet and close the bag at the top. No additional watering is necessary until the cutting is rooted and the bag opened.
Cleanliness
Pots, medium and equipment used for rooting cuttings must be clean and sterile. Pots should be washed thoroughly using a household cleaner and disinfectant. Tools also should be washed in the same solution or dipped in alcohol. Any rooting medium which is not known to be sterile can be moistened and heated thoroughly in an oven at 150 to 200 degrees for 20 to 30 minutes. Normally, peat moss, vermiculite and perlite don’t need sterilization when new.
Inserting the cutting
Promptly place the prepared cutting in the rooting material; stick the base of the cutting 1 or 2 inches deep, depending on the length of the cutting. Firm the material around the base and settle the medium by watering.
Care of cuttings
Never allow the propagation medium to dry out during the rooting process.
Since the cuttings have no root system, a high humidity must be maintained around them at all times. Clear plastic is inexpensive and easy to use for covering the cuttings. A plastic bag slipped over a pot is simple and airtight. Support the plastic with wire loops or stakes if need be to keep it from resting on the leaves.
Never place a plastic-covered container in direct sunlight. Too much heat will build up under the plastic and burn the foliage.
Care of rooted cuttings
The length of time needed for cuttings to form roots differs greatly among plants. Check the cuttings occasionally by carefully removing a few from the medium. When a cutting has roots at least an inch long, transplant it into a separate container.
The move from high humidity and moist rooting conditions to lower humidity and drier soil is the most critical step in successfully growing new plants from cuttings. Give these young plants close attention the first few weeks after the move.
A good potting medium designed for houseplants can be found at local garden centers or mass merchandisers and will be suitable for potting newly rooted cuttings.
After a cutting has become established in the medium, apply a soluble houseplant fertilizer according to directions. Then fertilize at monthly intervals. When the cutting is growing vigorously, normally in spring and summer, fertilizer may be applied every two weeks.
Division
Division is the easiest method of multiplying plants that naturally produce offsets or basal shoots. These new shoots usually have a few roots and can be separated and planted individually. Some plants suitable for division are listed in the table on this page.
Layering
Layering is a method of rooting a new plant while the stem is still attached to the parent plant. It is simple to perform and can be done in the home without special equipment or structures. Methods of layering include simple, tip, air and compound.
Air layering is the most suitable method for use on houseplants. It is convenient to do in the home and can be used with plants that would be difficult to root by any other method.
Mature wood, about one year old, is generally best for air layering. Old branches or immature wood often root poorly or not at all.
The air layer may be made at any point on a stem of proper maturity. On many plants a convenient location is 12 inches from the tip.
Air layering
- Remove all leaves several inches on either side of the point where the layer is to be made.
- From the center of the layering area, make a slanting cut upward an inch or more in length and about halfway through the branch. A preferred method of wounding is removing a strip of bark 1/2 to 1 inch wide around the branch (see Figure 7).
- Apply a rooting hormone to the wounded surface or cut.
- If a cut has been made, don’t let it heal back together. Insert a small piece of wood such as a toothpick in the cut to keep the wound open.
- Take a handful of unmilled sphagnum moss that has been soaked in water and squeeze out excess water. Pack the moist sphagnum around the branch to cover the wound.
- Cover the ball of moist moss with plastic wrap. An 8- by 10-inch sheet is generally large enough. Wrap it around the moss so that it overlaps and will not allow the moss to dry out. Clear plastic permits you to see when roots have developed.
- Secure the plastic at each end with electrical tape, string, plant ties or other convenient fasteners. It will usually take a month or more before roots appear.
Compound layering
Compound layering is suitable for long vines that may be alternately covered and exposed. Wounds should be made on the lower portion of each curve.
After rooting, the branch can be cut into segments, each containing its own roots.
Care after rooting
Root systems of newly rooted layers are small in relation to the canopy. After they are severed from the parent plant and potted, the humidity must be kept high. Enclose them in a loose, clear plastic bag for the first week or until they are well established and do not wilt excessively.
Copyright 2000 University of Missouri. Published by
University Extension, University of Missouri-Columbia. UExtension
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