10. How to Increase Your Plant Supply

As the owner of a small greenhouse, you will find it more profitable to buy rooted cuttings of foliage plants, geraniums, hoya (wax plant), hydrangeas, and many others than to give over space to propagating them. But in the case of rare plants, such as hybrids you have developed or collector's varieties of African violets or gloxinias, you will want to grow your own stock. With African violets you need not wait for good-sized plants to develop from cuttings; zealous collectors will buy rooted or un-rooted leaf cuttings taken from choice plants.

A propagating case made of plastic, an ordinary flat with a glass or plastic covering, or a flat of soil with a heating cable installed in it will speed rooting of all kinds of cuttings and hasten seed germination too. Sphagnum moss, sand, and vermic-ulite are ideal for rooting cuttings. As they contain no nutri­ents, material rooted in them should be shifted as soon as pos­sible to regular growing soil. If you cannot shift plants right away, feed them with a weak solution of liquid fertilizer, to prevent spindly growth.

How to Take Cuttings

Use a sharp knife to take a cutting. There are two kinds— stem and leaf. Most plants, geraniums, coleus, fuchsias, and wax begonias, form new roots more rapidly when the stem cutting is taken about 1/4to 1/2inch below a node (the leaf-stem joint). Two or more top leaves are left on but the lower ones are stripped off, and all flower buds are removed.

30. An important factor in the production of "healthy geraniums for healthy profits" is timely transplanting of the well-grown cuttings. In view of its root growth, the young plant in hand is just about ready to go into the next larger-sized pot.  (Photograph by Roche)

Stem cuttings of cacti, geraniums, and poinsettias should be allowed to dry in the air for at least 24 hours before planting. In fact, some cacti specialists let the cuttings dry for 4 to 6 days before planting. With plants that have juice-filled stems, this drying time forestalls possible rot.

Leaf Cuttings

African violets, gloxinias, and other gesneriads, rex begonias, peperomia, hoya, echeveria, and sedums are among the many plants you can propagate from single leaves.

Cut the leaf off with about ½ inch of petiole (leaf stem) and insert it in sand, sphagnum moss, vermiculite, or a mixture of all three, right up to the edge of the leaf blade. If you are using a heating coil for faster propagating, keep the soil tem­perature about 75 degrees and the air temperature 70 degrees.

You can transplant the cuttings to 2-inch pots after 2 or 3 weeks, or you can leave them in the propagating case until they show new plants—usually in about a month—and then transplant them.

If you have some especially nice geraniums you want to in­crease, try propagating them through the leaf-bud system. In each leaf axil (the point where leaf stem joins plant stem), there appears a small bud of new growth. Make your leaf cut­ting so this growth bud remains attached and propagate as you would single leaf cuttings. With this method you will get many more cuttings per plant than if you had taken regular slips. These cuttings root within  10 days.  Azaleas,  bougainvillea, chrysanthemum,   and  croton  are   some  others  to  propagate through the leaf-bud method.

31.  Seedlings  are delicate.  Transplanting them from  a crowded seed flat (as with these coleus seedlings) to a growing flat should be done gently but quickly to prevent drying of root hairs or excessive wilting of plants.   (Photograph by Roche)

With rare varieties of rex begonia or gloxinia, you can multi­ply your stock by another leaf-cutting method. Take a leaf and slice through the large veins in several places. Insert the cut-veined leaf in a propagating case, in moist sand, and little plants will form at each of the cuts

32. An all-plastic propagating case—glass would be just as good but not so durable—will make short work of rooting gloxinia and African violet leaves. The combination of strong, all-around light and high humidity does the trick.   (Courtesy, House Plant Corner)

Air-Layering

If you want to produce more plants from an aged and un­gainly rubber plant or dieffenbachia, make a slit in the stem just below some shapely top growth. Moisten a handful of sphagnum moss and place it around the slit stem; then wrap with polyethylene plastic. Secure the plastic and moss packing, top and bottom with rubber bands or with the covered-wire Twist-Ems.   Keep   the   moss   moist—which   is   not  much   of a job since the plastic blocks the passage of water vapor while permitting the passage of air. Indeed, you may not have to water but once during the usual 6-week rooting period. When the ball of moss is filled with roots, cut the stem below the roots and put the "new" plant in good greenhouse soil.

33. Producing new varieties is often profitable for the home greenhouse operator. The more you know about the flower structure of different plants the better your chances for success. These are begonia flowers: a male or pollen-bearing flower on the left and a female or pollen-receiv­ing  and  seed-producing  flower  on the right.   (Photograph by Travis Studio)

You can keep the old plant too, for it probably will sprout new foliage. This type of propagation is called air-layering. Soil layering is based on the same principles; but in this method, stems are bent down to the soil and rooted there.

34. This is a picture story (counter clockwise) of making money with gloxinias, from pin-point-sized seeds and pin-head seedlings to a small mail-order sized plant and a larger cash-and-carry specimen. Photograph by Roche)

Propagating Bulbs and Tubers

You can break off scales from an Easter lily bulb and root them in any medium. Likewise the scales from rhizomatous gesneriads, achimenes, kohlerias, and smithianthas; each scale acts as a seed and produces a new plant.

Tubers of tuberous-rooted begonias and gloxinias can be divided so long as there is at least one eye (growing point) for each division. These can be started into new growth in almost any medium.

The common amaryllis and many other amaryllids, as well as hyacinths, can be propagated by scooping or gouging out the bottom of the bulb, or by making slashes in the base. Then the bulbs are planted in sphagnum moss or sand and given bottom heat of 70 degrees; they will form new bulblets in the cut areas.

Plant Division

Most plants capable of being reproduced through leaf cut­tings can also be propagated through plant division. Most perennials—artemisia, campanula, hosta, and peonies—and the majority of house plants can be thus divided.

Use your hands to separate the plants or, in the case of heavy rooted hostas or peonies, use a sharp knife or spade.

Divisions are then planted and rooted or grown on in the greenhouse, cold frame, or perhaps in the garden.

Planting Seeds

One of the most economical methods of reproduction is through seed. Fine seed like that of most house plants is sprin­kled lightly over a moistened medium, then covered with glass or plastic, and placed in a warm (70- to 85-degree) germina­tion spot. Larger seed of some vegetables, perennials, and an­nuals is planted in soil or other growing media and then covered to its own depth with sifted soil. As soon as plants have formed true leaves, they are transplanted to flats of soil or individual pots.

35. Here is a propagation method that is just as simple as it looks. The gloxinia leaves, inserted in vermiculite, get the moisture they need (after initial watering) from the water-filled pot reservoir in the center of the rooting pot. The bottom hole of the small clay pot is sealed so that water seeps evenly into the vermiculite through the pot's porous walls. (Photo­graph by Roche)

36. Let it snow—the seedlings are coming through the soil and the well-ordered greenhouse promises healthy plant development. A variety of good cash crops is in the offing. (Photograph by Roche)

Ferns from Spores

There are few fern specialists in the United States, so ferns might prove a profitable crop for your greenhouse. There are many kinds and they have many uses indoors and out. Ferns are propagated through spores—those brown spots appearing on the underside of the fronds.

As ferns develop their powdery spores, cut away the entire frond and place it in a paper or plastic bag. The spores will mature in 3 to 4 weeks and be ready for sowing on milled sphagnum moss or sand and leafmold. When the new plants show several leaves, transplant to 2-inch pots of porous soil.

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