Azaleas, roses, forsythia and several other kinds of plants can be started from softwood cuttings taken at this time of the year. A softwood cutting is like a fresh string bean instead of bending, it is okay; if it is soft and rubbery and does not snap, it is not suitable.
The softwood cutting roots quicker than one of older wood, usually in eight to 10 weeks. The older the wood, the longer many kinds take to root, and a cutting can live for only a limited time without roots.
That is why it is almost impossible to root a branch that has been broken or cut off a shrub. It involves trying to get roots on two-year or older wood and the chances of success are poor indeed.
By enclosing the potted cutting in polyethylene plastic, the kind sold for storing fruits, vegetables, and other foods, it it possible to create a minature greenhouse for rooting it.
The plastic is impermeable to water vapor but permeable to air, carbon dioxide and oxygen, which can flow in and out. This maintains a high humidity inside the plastic, and there is little risk of wilting because loss of moisure from the leaves is no greater than the limited amoutn that can be absorbed through the cut end of the stem.
Early morning is the best time to take the six-inch cuttings. Use a sharp knife. Make the cut a quarter of an inch below a node (the junction of leaf and stem). Remove only the lower leaves, leaving on as many as will be above the soil level. Put the cuttings immediately between moist newspaper. If they dry out they may wilt and if they wait they may not root.
Cuttings should be planted immediately, but they can be stored for a few days in a slightly moist plastic bag in the refrigerator or a similarr cool place.
For small lots of cuttings, use clean clay pots about six inches in diameter. Each one should hold about six cuttings. The leaves of the cuttings should not touch each other.
A good soil mixture for the cuttings is two parts sphagnum peat and one part vermiculite or perlite. Vermiculite and perlite are both free of disease organisms, and the peat is usually disease free, too.
A hormone such as Rootone or Hormodin can be used to a speed rooting, but it isn't esential to succes. Hormodin No. 1 is best for evergreen azaleas. Directions on the label should be followed closely.
The effect of treating cuttings with such substances is to increase the percentage of cuttings that root, lessen time required forr rooting, or induce the development of more or better roots.
Cuttings of plants that root with difficulty or not at all without treatment are, unfortunately, the ones least likely to benefit by treatments.
After planting the cuttings in the pot, water thoroughly and enclose the pot in the plastic bag, sealing it so that water cannot excape.
The moist mixture in the pot continually evaporates water taht cannot escape, resulting in continyous high relative humidity within a bag. The pot will not usually need to be watered again.
Check the cuttings in about eight weeks to see if they have long, the cuttings can be planted in individual pots or in the garden outdoors. Shade them or a week or two after transplanting to help them become established. Keep them watered.
Research has shown that cuttings from very young trees will root much quicker than those from olderr ones.
Dr. Bob Hare, Southern Forest Experiment Station, Gulfport, Miss., has discovered a way to root cuttings of both pines and hardwoods. Key to the process is girdling the shoot a month or two before cutting. Food reserves therefore accumulate above the girdle where they cause callus tissue and root primordia (small bumps) to form.
No expensive growth chamber is needed for this technique, Hare says.Success can be achieved under ordinary greenhouse conditions. And if no greenhouse is available, more simple ways such as use of polyethylene plastic, can be used.
Select branches well exposed to the sun in the lower part of the three. Remove all foliage from a two-inch section of stem, about six to eight inches below the terminal bud. Remove a one-inch ring of bark down to the wood in the defoliated section.
Apply Hormodin 3 to the upper portion of the girdle with a camel's hair brush. Wrap would with plastic film followed by aluminum foil. Leave intact six weeks for hardwoods, eight weeks for pine. Then sever cuttings below the girdle and take to greenhouse. Remove the plastic film and foil. Choose the cuttings with bumps (root primordia) on the callus. Moisten the cuttings base with water and insert the cutting base two or three inches deep in a rooting medium and enclose in polyethylene plastic.