Growing new plants from old Garden: Cuttings from outdoor favorites can be brought indoors and induced to root.

November 15, 1998|By Ary Bruno | Ary Bruno,SPECIAL TO THE SUN

As crazy as it may sound, winter can be one of the most productive times of year for the gardener.

With just a few minutes and a handful of simple materials, anyone can practice the art of rooting cuttings, one of the easiest and most reliable ways of propagating favorite plants, and the quickest.

Autumn is an excellent time of year to take cuttings of annual flowers such as geranium and impatiens for indoor bloom, tender perennials, and hardy herbs that you would like to have fresh on hand.

Many shrubs and even trees can also be propagated from cuttings over the winter, if you have a mind to increase your plantings. This is especially useful for expensive, hard-to-find or heirloom varieties.

If you have a sunny windowsill in a coolish room, 55 to 68 degrees, you have the makings of a fine winter nursery.

This is also a convenient way to get a head start on spring, when gardeners are frequently frantic with a hundred other tasks.

Geraniums, impatiens, begonias, gloxinias and other annuals are brought inside before frost. Tender perennials and most herbs can stand a light frost, but will perform better if given a head start inside before then. These are called softwood cuttings.

Rosemary, sage, thyme, tarragon, oregano, parsley, lavender and all the mints do well, and a cozy row of herbs lining the kitchen windowsill is as cheerful as a smile. Basil, too, can be rooted and potted up for inside use, but because it is day-length sensitive, it will require several additional hours of bright artificial light to keep producing.

Flowering shrubs and trees, which yield hardwood cuttings, often do better after they have had a bit of a rest - from four to six weeks - in the cold weather. Mid-November is not too late to start them, or even into December in a mild year.

Almost anything is fair game for this. Even interesting "lively" stems from castoff floral arrangements, such as corkscrew willow (Salix matsudana 'Tortuosa') and fragrant viburnums can be induced to root without much coaxing - indeed, in the case of willows you may find they have already started to root in the vase.

Red twig dogwood (Cornus alba 'Sibirica') roots well from early winter cuttings, as will most fruitwoods, roses, forsythia and boxwood. Besides, you can't lose anything by trying!

The technique is simple.

The cutting should be taken from a part of the plant that is neither so soft that it crushes when you try to bend it, nor so hard that you cannot snap it between your fingers. The stems should be mature, but not woody, and still bend easily and not be in bloom.

Make your cut just below a joint or node. This is the point where new roots will form most readily. Four to 6 inches is a good length; one or two buds on the upper part will also facilitate new growth.

You can use either a standard sterile potting mix of peat moss and vermiculite or sand, which will provide the good drainage necessary. Many softwood cuttings can be rooted in a glass of water and then transferred to pots when the roots are a quarter of an inch long.

Sand, soil or potting mixes should be moistened and packed gently into small pots. For single plants, use pots 2 to 4 inches in diameter, or you can put several cuttings into a larger pot, spaced about 2 inches apart.

If you are planting a lot of cuttings of one kind, consider using a propagation flat, which is an 11-by-22-inch plastic tray without holes. Ground covers, English ivy and the like do well this way, rooted in moist sand.

With a pencil or stick, make a hole in the center of the soil in ## each pot. The part of the cutting that goes in the rooting medium must be stripped of leaves. The root end is dipped about 1 inch deep in hormone rooting powder (available at local nurseries and most garden centers) and placed in the hole without disturbing the powder. Firm the soil around it, and you're done.

When you have finished, water the pots until moist, but not soggy.

Place them either on a sunny windowsill or enclose each in a clear plastic bag; prop up the bag(s) over the plants with small, wooden sticks. Put them under fluorescent lights, which should be kept on for 12 hours a day, about 4 inches above the tops of the plants. Do not use plastic bags if you are putting the plants in direct sunlight - you will end up with cooked plants.

Check your plants daily. Remove any dead or moldy cuttings or leaves promptly. Never let the plants dry out, or you will lose them - but don't let them get soggy either. Mist the plants to keep the humidity level high.

After two or three weeks, most plants will have begun to root, although hardwood cuttings take longer than softwood. Usually, when the plants have begun to send forth new leaves, a root system has been established. If you are using plastic bags, remove them.

A location in a cool but bright room or sunny window is best. A cool room is preferred because it encourages root growth rather than just leaves. Hardy plants and most shrubs and trees can be moved to an unheated, enclosed porch or a cold frame.

Supply additional lighting as needed: though most plants will do fine without it, they will make sturdier growth with more light, to mimic spring day length and light intensity.

Light weekly feedings of seaweed emulsion or other low-nitrogen fertilizer are recommended (5-10-5 is good), or topdress the plants with compost at monthly intervals as long as the plants are "held."

Hardier plants can be moved outside to a sheltered location to harden off in mid-March, and be planted out a couple of weeks tTC later. Roses and most tender flowers and plants should be kept in a frost-free location until late April or mid-May.

Pub Date: 11/15/98

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