My gardening friends certainly vary as to ability, inclination, talent, and aptitude. At one extreme there is Aunt Minnie, whose green thumb injects magic into every pot and for whom every plant grows to buxom, blooming perfection. At the other end of the scale there is the poor soul who tries so hard but can’t keep a plant alive no matter what she does. Why do some plant-lovers never fail, while others never seem to win? There are a number of reasons, including a difference in growing conditions, variations in the types of plants, and even the amount of practical experience or common sense Aunt Minnie is blessed with.

The truth is that there is no single, incontrovertible secret to success, but rather a combination of many factors of equal, or nearly equal, importance. The best soil in the world won’t make plants flower unless temperature and sunlight are right. The frequency with which you water plants should be affected by indoor temperature, humidity, and pot size. And don’t think it is Aunt Minnie’s favorite brand of fertilizer alone that keep her plants in good health.

In our house, and in countless others, it is not possible to make growing conditions as perfect as a plant might wish; but we try to come as close as we can, and find most plants are willing and able to make concessions. One more thing we do. We learn all about each plant’s natural home—desert, steamy jungle, Mexican mountainside—so we’ll know what combination of conditions it likes best.

CARE OF HOUSE AND GREENHOUSE PLANTS

Light and Sunlight

Plants need daylight to make energy; they can’t grow without it, or its equivalent in artificial light. They need some sunlight to set buds, and can’t flower without it or a substitute. Intensity and duration of light should vary according to each plant’s preferences.

No plant of ours is left to waste its life away on the fireplace mantel, where the light is too dim to read the printing on a book of matches. Granted, we might set it there for a day or so as a decoration, but we would return it to its bright window sill before it began to stretch out weakly in search of light. These are the signs of insufficient light—weak, lopsided growth; leaves that feel limp and look pale; new leaves, if any, growing progressively smaller and smaller; long leaf stems and long internodes.

Our window greenhouse, which faces south, is reserved for flowering plants that need all the light and sun we can give them, particularly in winter. This is Connecticut, remember; the winter sun seldom gets very hot or stays bright very long. And there are days on end when the sun simply does not show its face. California’s “shade plants”—begonias and fuchsias, for example—require full sun during a Northern winter.

For plants that are not quite so greedy for sunshine, we have the east-facing playroom picture window, which is lightly shaded by a high-branched deciduous tree in summer. For foliage plants, and a few others that will thrive on little or no sun, there are several other windows around the house where there is plentiful daylight, but the sun is seldom seen.

Your situation may be entirely different—perhaps a glassed-in porch that’s brighter than our window sills ever will be; or a contemporary-style glassed-in entry that lets sun stream in all winter long. Keep in mind that various plants have varying needs for light and sunlight; and the only sun that benefits a plant is that which falls directly on it. A south window may actually be shady in summer, and this is truer the farther south you go.

Temperature

Some plants grow their healthiest when the thermometer reads 50 to 55 degrees at night and 5 to 10 degrees higher during the day; some tender tropical émigrés suffer a chill when the mercury dips under 60 degrees at night. But the greatest number will tolerate a fairly wide range, and are quite content with whatever the house has to offer. This again assumes that other conditions, such as humidity, are kept up to the plants’ requirements.

Temperature tolerances are directly affected by the humidity in the air. Many plants will accept a temperature that is higher than average if the air is moist. Some will accept a temperature that is below average if the air is not too moist. In air that’s too hot and dry, leaf edges will often turn brown and crisp; when it is too cool, a plant may stop growing temporarily; when it is both too cool and too moist, there may be danger of rot. Don’t trust the thermostat that governs your house heating system to tell you whether the temperature is right for a plant; measure it on the very spot where the plant is growing.

Humidity

This is often a more crucial factor than temperature, and one that is more troublesome to change. Relative humidity is a measure of the amount of moisture in the air as compared with the maximum amount of moisture the air can hold at a given temperature. It is expressed in percentage figures.

Most plants find it difficult to breathe in dry air; they need some moisture around, on, and in their leaves. (People are better off when they have it, too.) Alone, or teamed up with unsuitable temperature, low humidity can cause leaves to wither, buds to drop before they open, and even an invasion of mites or some other pest.

A humidity gauge is not nearly so familiar a household item as a thermometer, but it is equally useful, usually better looking, and not much more costly. And it can come up with some eye-opening information. The humidity gauge will tell you very quickly, for example, when an air-conditioning system is missing its recommended mark of 50 per cent relative humidity. It will stop you from overwatering in muggy weather. It will show you that humidity can be dangerously low in the window where your plants are growing, even though it is perfectly acceptable three feet away. (Perhaps there is a radiator beneath the window.)

What you do to increase humidity depends on how low it is, and on what type of plant you are growing. At our house we have three systems for the humidity problem—the lazy, the halfway, and the necessary nuisance. The lazy way works fine for dry-air-type plants such as most cacti and other succulents. We simply grow them where the hot blasts from the radiator are strongest. They don’t wither, and when on sunny days we water them, we also mist them with a fine water spray. (For an easy misting device, we have an old Windex bottle with a spraying attachment in the cap. It does a fine job. Of course, there are other commercial products with built-in sprayers. Perhaps you have one in your kitchen.)

To go “halfway,” you set up some simple humidifying device. The containers which you fill with water and hang behind the radiators are effective to some extent. But don’t forget to keep them filled. Pans of water on top of the radiator also help. A steam kettle, such as you use when the kiddies have a chest cold, can be used for a few hours. But remember, that steam is hot, so be careful not to get it too close to your plants. Just keep it in the general vicinity; please, not too close! Here is something else we often use—put some gravel, sand, perlite, or vermiculite in a plate or platter, pour in some water, and put your flower pot in it. The water will evaporate and moisten the air around your plant. If you have a number of plants, get a metal or plastic tray. If you have a decorative garden, you might want to have a tray made to order, to fit your space. Paint it a pleasing color. I have seen such trays decorated with decals, but personally, I’d rather rely on my plants for the necessary decoration. In having a tray made—we’ve had several made by our tinsmith—the larger the tray, the better.

The “nuisance” system is usually necessary only for very delicate tropical plants that flourish in highly humid jungles and rain forests. They will need the platter, or tray of moist sand, plus some enclosure to hold in the moist air. For a single small plant, this can be an inverted bell jar, or a tent made from a polyethylene bag (the sort vegetables are often packed in) and propped over the jar and plant. A larger bag can be used to protect several plants. You can even use kitchen-type plastics such as Saran Wrap. A collection of tropicals almost calls for an indoor greenhouse, like the oldtime Wardian case. In our window greenhouse we can close the inside sash and, with the aid of pans of water, keep the humidity just about where we want it. On cold nights the electric-coil heater isn’t always adequate, so we open the sash to get the benefit of the heat of the room.

The plants that need this extra humidification are definitely in the minority; most are content with simple measures, or none at all.

Soil

When I first became interested in a wide variety of indoor plants, I prepared soil mixtures with the care and precision I had used in making the formulas for our children. It involved trips to the woods for leaf mold, sifting and mixing ingredients, and sterilizing the ordinary soil which we used in order to kill the seeds that are found in almost all soils. In our Long Island home we had an extra stove in the basement which we used for canning and other secondary purposes. I’d fill the oven with old baking pans and other receptacles which contained my potting soil, and light the burner. Frankly, it “reeked” and the reek was all over the house. It was as though we were burning feathers in the fireplace. Now that I am less energetic, and somewhat wiser, I buy prepared soil.

I find that for a reasonable number of plants the prepared soil is not costly and saves a lot of time and preparation. Of course, if you are a professional you may have your own ideas about soil, and your own formulas for a mixture. I’ll admit I do a little mixing on my own, but that is because I grow many different kinds of plants in pots, and each has individual preferences. Most cacti and succulents need something sandy that doesn’t hold moisture too long, as is natural in their desert homes. Tropical plants need a light, porous medium that is rich in moisture-holding humus, like decayed leaves on the jungle floor. Some plants get nourishment only from acid soil, some need alkaline soil, some like soil nearly neutral. I’ve found Michigan peat moss a good starting base regardless of requirements of individual plants.

I like to dish it right out of the bag. When done, I always pull the plastic inner liner together to keep it moist. In extra dry weather I often wet a sponge and put it on top of the mixture. Potting is a pleasure, because Michigan peat feels so soft, silky, and clean. At repotting time I discover well-developed, healthy root systems.

For plants that require better-than-average drainage—mostly succulents—I mix peat moss with builders’ sand. (Want to know where I got my last batch of builders’ sand?—from a contractor who was building a house down the road. He and his wife happen to be begonia lovers and he was charmed to know about my book All About Begonias.) The formula for the mixture is two-thirds soil and one-third sand. For even greater aeration, I may throw in a moderate ration of crushed charcoal.

On the other hand, some of my plants insist that their soil always be moist. For them I add coarse vermiculite, perlite, or Pelonex, and in a similar ratio. These soil conditioners have the ability to hold moisture without making the soil muddy or soggy.

There is another item on my potting-soil shelf—a jar of horticultural lime. This is for plants that dislike acidity. I either add it to the potting soil—a scant teaspoon per three-inch pot—or mix it with water, to be applied later. With or without these added ingredients, I feel that a good potting soil has sufficient nutrients for almost any plant for several months; so I seldom mix in fertilizer of any kind.

Potting

When and how to repot a plant should be the least of a gardener’s problems. Here is a case where hovering, pampering, and fussing usually does more harm than good. Plants are often better repotted mañana than today.

I know many of my plants have benefited from the fact that I have been too busy to repot them whenever the impulse came over me. I hate to think how many I have killed with kindness in my less active years.

Remember my Aunt Minnie? She embarked on a big repotting spree every spring, but not very often in between. Some of her most handsome specimens have lived in coffee tins and large juice cans for years. Instinctively she knows when a plant should be repotted. Don’t ask me how she knows it. And when that time comes, she goes about it in a firm, no-nonsense manner, firmly but tenderly.

There is one sure way to tell whether a plant needs a new pot. Turn the old pot upside down, tap the contents loose, and examine the soil ball. If it is completely covered with a network of roots, get busy with a larger pot. If not, don’t repot, just slip it back where it was before and give it a loving pat. If you happen to have a seedling you have great hopes of raising to a beautiful maturity, it will have to be repotted more often.

The kind of pot is a matter of personal choice. Plastics are lighter in weight, easier to clean, and capable of keeping soil moist for a longer period of time. This makes them suitable for moisture-loving plants, or for gardeners who have a tendency to forget the watering pot. Clay pots are porous, and because they let air seep into plants, they dry out faster. This makes them best for dry-growing plants, and for overwaterers (like me).

Actually, the size of the pot is more important than the type. It takes an expert to know how to water a plant when it is overpotted. You are not doing your plant a favor by housing it in a pot several sizes too large; in fact, you may even be signing its death certificate. As a rule, the new pot should be only one size larger than the previous one, thus leaving just enough room around the roots for some fresh soil. Pack the new soil firmly with your finger tips, a pencil, or a slim piece of wood. Be sure there are no empty air-pockets. Water it thoroughly and set it in a light, but not sunny, spot, for about a week. This will give it time to recover from any transplanting “shock.”

This discussion about overpotting applies to plants in general, but it is even more important with miniatures. Smaller pots will keep them down to natural, miniature size.

Fertilizing

Many people who have fewer plants than I—and more time—tend to make a fetish of fertilizing. I am afraid my methods are haphazard, and not to be recommended. Anyway, I will tell you what I do. Follow it if you like, but quite possibly you may have a better method which you prefer.

I keep two kinds of house-plant fertilizer on hand—a reliable brand of soluble commercial chemical plant food (it dissolves in water and has the note “trace elements added” on the label) and an organic food. This organic food is either manure water or fish emulsion. The fish emulsion comes bottled and is diluted with water. As an amusing sidelight, our tomcat goes slightly out of his mind when around a potted plant that has had fish emulsion for its dinner. The cat just can’t find the source of that aroma. Manure water, on the other hand, has no such fascination. It is easy to prepare. Simply wrap a portion of well-rotted manure in a section of cheesecloth or burlap, and steep it in the watering pot long enough to produce a “tea” fluid. Better do this out of doors, in the garage, or in the tool shed. It is usually “olfactorily offensive.”

Once a month I make a solution of the chemical fertilizer, at half the strength recommended on the label of the package, and feed plants as I water them. Two weeks later, and once a week after that if they need it, I feed with the organic solution. This, I think, constitutes a “balanced diet” for most types of plants.

Like overpotting, overfertilizing can lead to lost plants. It is my observation that an underfed plant usually doesn’t die quickly. It simply slows down until you have time to feed it. It is particularly important not to fertilize plants that have been repotted recently, plants that are unhealthy or are plagued by insects or disease, plants that are resting right after flowering, plants that are dormant or semidormant, as some of them are at certain times of the year. Do fertilize plants that are in active growth, setting buds, or in full bloom, plants that are aglow with good health, plants whose roots have filled, or nearly filled, their pots.

Watering

My children, who are learning to care for plants rather early, have been grounded in one fundamental fact—feel the soil in the pot to see if the plant needs water. If the soil is dry, fetch the watering pot (succulents can be an exception). I have been told my kiddies have had arguments at school about watering the plants which cluster on the sunny window sills. The usual procedure in our Redding school is to assign the care of the plants to a different child each day. He, or she, floods everything with water and then retires to his, or her, desk with the feeling of having done his, or her, good deed for the day. Plants, alas, are not like goldfish. They don’t care for swimming.

This brings up a question I am frequently asked about house plants: “How often should they be watered?” Even an IBM calculator with a thousand cards feeding through its maw couldn’t come up with a better answer than this simple statement: “Water them when they need it.”

At the risk of repeating myself, I will sum up my thoughts on this problem, and then go on to other subjects. Test the soil with your fingers, if it is dry, you can most likely water with impunity. If moist, more water is inviting root rot. When you water, make sure the entire soil ball is so saturated that excess water runs out the drainage hole in the bottom of the pot. Miniature plants are likely to require more frequent watering, because their pots are small and they are small. Frequency of watering: Here we get into an awful lot of tangibles, and some intangibles. There are such things to consider as the type of plant and its moisture needs, size of the plant and its pot, what sort of soil is in the pot, is the plant root-bound or not, is it in active growth or dormant, what is the weather like out of doors—is it warm or blustery, clear and sunny, dark and humid, or just another day. Remember, on hot dry days the moisture is going to slip away into the atmosphere. On cloudy days it will hang around longer; humidity will take care of that. If you feel your plant needs water and you are afraid of flooding it, you might try another device. Put some moist peat in a larger pot—or you can use vermiculite or perlite—and set the plant and its pot inside this larger pot.

Right now you may be wondering about hanging baskets and those plants that are wrapped in osmunda and mounted on slabs of wood. Give them a good dunking in the kitchen sink but let the excess water drain off before you hang them again, out of deference to your carpeting and furniture. Actually, the plants don’t care whether they spot your furnishings or not.

If all of this is confusing, may I sum it up in a phrase: “Just use your common sense” (horse sense may be a better term). I know I have written a few books about plants and gardening, and countless magazine articles, but here is a very candid confession. Until a very few years ago I knew practically nothing about the subject. What I know I learned by reading books and magazine articles, and “doing.” I know I killed a few plants out of ignorance, but I killed more with kindness. Every time a plant withered and died I felt badly. But I considered it a lesson in what to do, or not to do. I tried to find the cause for the demise. Today I have the satisfaction of having raised thousands of plants to beautiful bloomhood, and largely because of the sacrifice of some obscure begonia, or petunia, a few years back. I have been acclaimed as having a “green thumb.” Actually I do not have a green thumb. No one has. I thoroughly dislike the term. I dislike the implication that a person has a God-given quality which makes plants grow. Making plants grow and prosper is largely the mastering of a few rules, and the use of a lot of common sense. I’ll grant you, much of your common sense comes the “hard way.” But it is fun. I bow most respectfully to those plants which I killed with ignorance and kindness.

Grooming

This is the “beauty-parlor” treatment for your plants. Fading flowers and dying leaves are as unattractive on a plant as those unruly ringlets in a woman’s coiffure. In fact, they are even worse. They take strength from a plant and are unsanitary. Remove them as regularly as you can. You’ll be adding to the welfare of your plant. If the plant is of a type that needs to be pruned or pinched to keep it comely and compact, perform the operation before the branches get that gangly, middle-aged spread. Pinching out the new growing tips, either with sharp fingernails or sharper scissors, usually produces two new branches. If you pinch out the tips of these, you will most likely get four new branches and your plant will become pleasingly plump. The exception is the plant that blooms from the ends of new growth. Stop your pinching before the bud-setting season.

Not many miniatures need staking to keep them upright. If stake you must, do it as inconspicuously as possible and tie the stems neatly in their natural growing manner. Train miniature creepers in the direction you want them to grow, and miniature climbers up their supports. Rinse foliage with a fine spray (use that discarded Windex bottle I described earlier) as often as you can to wash away dust and dirt. Please, may I throw in a plea right here—recently I saw a commercial product which some people use to make their plants more green. It is a spray for foliage. For the moment it makes plants look green with its sheen. But it also clogs the pores on the plant and its leaves. For the moment it is beautiful; for permanency it is harmful. Decide, do you want your plant to live for the moment only?

Insects and Disease

Not long ago, when visiting a friend, I was taken out to her sun room to see her plants. She was proud, but I was shocked. What I saw was the most amazingly bug-ridden collection of fuchsias and geraniums I have seen in many a moon, plus a few poor distorted other flowers which were trying to survive. My poor hostess, honestly, I think she had no idea of her problems and the future of her plants. In fact, they had little future. I thought over that problem for a spell, and then told her the facts of life. Fortunately, she was able to save much of her greenery.

That poor gardener was on one end of the spectrum. On the other end are the overanxious ones who treat their plants with so many sprays and dusts that the leaves never get a chance to breathe pure air. Fortunately, in between there are the sane, sensible growers who are able to cope with the insects and diseases which beset house plants. As for myself, I have been at both extremes.

I now find prevention is the best protection. That is an old saw, but the best one I know. I keep plants and pots clean, remove dead flowers and foliage before they decay, and use germ-free potting soil. People often give me plants. I accept them most politely, and gratefully; but I am cautious about mingling them with my other residents of the greenhouse and window garden. I keep them in a quarantine section for a few weeks. No use asking for trouble, and I trust my friends understand.

For immediate and reliable treatment, I rely on an “all-purpose” house-plant spray or a dip. As long as I am careful to keep it up, I seem to have no great problems. When I get careless, as humans are wont to do, I regret it.

It is very convenient to rely on the new aerosol bombs—those that are specifically marked for house plants, and not those for household insects. There are several reliable brands, each listing on the label what they are to be used for. If there happens to be an added fungicide, so much to the good. That will cover just about everything.

A few words of caution about the use of aerosol bombs. Follow the instructions on the label to the letter. Hold the bomb at least eighteen inches away from your plant, maybe more. Some of those fluids come out of the can at a very low temperature and have the same effect as a blowtorch on foliage. Try to make sure the spray hits all parts of the plant. Remember, leaves also have an underside. Don’t let bugs use that underside as a hide-out.

There was a word of caution on each aerosol container I have seen: “Do not throw into an open flame when empty.” My husband wondered what would happen if he did. He tossed an empty can into the trash burner and got behind a tree. The explosion sounded like a hand grenade left over from World War II and he had to get a new lid for the burner. Please take my word for it and don’t take that chance. Let him be crazy if he likes, but not you. I don’t like to lose readers so early in my book.

I know I take precautions, but in spite of everything my plants become infected at times. When that happens it’s helpful if you can recognize the symptoms, diagnose the ailment, and apply the cure. With your interests in mind, I have put together a list of sorts which includes the most prevalent house-plant insects and diseases, the telltale signs of their arrival, and the insecticides and fungicides which will send them to their happier hunting grounds. If I have skipped anything, my apologies. If you are having special problems, phone your local county agricultural agent. He is a good man to know anyhow. But please, unless you have something that is out of hand, don’t bedevil the man. He is probably concerned with ticks on sheep, ringworm, hog cholera, breachy cows, grubworms, and forty people who want to know why their hollyhocks didn’t bloom.

PROPAGATING HOUSE PLANTS

It’s hard to tell which provides the warmest pleasure, to give a friend or visitor a rooted, potted cutting of some plant she has admired, or to come home with a gift cutting of a new plant you have admired and coveted. There is a thrill also in adding a new plant to your collection by growing seed from a seed house. And I always have another thrill when the church or the school asks me to contribute plants for the annual bazaars. Fortunately, I usually am able to anticipate these requests far enough in advance to have a supply ready and waiting.

PESTS AND TREATMENT

Since I fashioned my first crude propagating box—a square cake-tin with a rickety frame covered with kitchen plastic—I’ve always had some sort of similar device in operation. They have been of many sizes and shapes, and have included an aquarium vacated by the children’s goldfish, and a fruit crate from the grocery with cut-to-measure glass sides and top (I use masking tape to hold the corners). The one thing common to all of these boxes is the three-inch layer of some moist propagating medium, ready to receive seeds and cuttings.

The latest and most attractive box I’ve used is the Gro-Master—a ready-made plug-in propagator with an electric coil in the bottom to provide gentle bottom heat. Several similar devices are also available. With something like this one can hardly miss germinating even the most difficult house-plant seeds, or rooting even the most delicate cuttings.

The choice of a propagating medium is all yours. I’ve used vermiculite, perlite, and Pelonex with unqualified success. I tried sharp sand but discovered that it dried out too fast for anything but succulents. Peat alone, or mixed with sand, tends to pack and rots rather quickly. I tried a blend of equal parts of peat, vermiculite, and perlite. It held up rather well, but I seldom bother to mix it. Regardless of what you prefer to use, have the medium moist when you use it, and water just enough to keep it barely moist during the rooting process.

Of course, with many types of plants, you can root “slips” in a glass of water on your kitchen window sill. But in any kind of propagating box, where the air is kept humid and the delicate plants are protected from drafts and drying-out, you have a better chance.

House Plants from Seed

African violets and other gesneriads, all types of begonias and geraniums, and many other indoor plants can be grown quite easily from seed. I like to plant each variety in its own small plastic refrigerator dish with a half-inch or so of soil (moist, sterilized soil that is) in the bottom of the dish. Sometimes I use plastic ice-cube trays. When planting powder-fine seeds, I usually add a thin layer of moist, finely-milled sphagnum moss and make it very smooth. Dust the tiny seeds over this surface, but don’t cover them with soil. Larger seeds should be covered with soil or more moss. Next, cover the container tightly and set it in a warm spot. That is when you will appreciate a propagating box. If the moss and soil begins to dry out, moisten it by gently running drops of water down the sides of the container. Please be gentle and tender. Tiny seeds and seedlings should not be disturbed.

When the seedlings have developed one or two true leaves of fairly substantial size, pick them out very gently and transplant them to another “community” container, or to individual thumb pots. Keep them humid and protected until they are big enough to need transplanting again. After that, they should be nearly ready to become adjusted to grown-up growing conditions in a window, or some other indoor garden.

One of the neatest tricks of the year is the Water ‘N’ Watch indoor garden developed and sold by Peggie Schulz, an attractive plastic planter complete with soil and planted with fourteen types of seeds. You simply follow her instructions, add water, and watch the seedlings germinate and grow. Gradually you remove the plastic dome when the plants are large enough. At transplanting time, remove the seedlings to separate pots, or leave a few to mature in the planter. This device is just about as work-free a method of growing house plants as there is.

Stem Cuttings

This is the most familiar way to propagate house plants, and the method that works best for most kinds of plants. With the exception of miniature orchids, stem cuttings can be taken from any house plant mentioned in this book, and your chances for success are very good if you have a propagating box for them.

Generally, stem cuttings are the ends cut from branches that are in healthy, active growth. Each should be more than a mere tip, and have at least two nodes, or “joints.” The large, bottom leaves are stripped off very gently and the cut end of the stem is inserted, to about half of its length, in the propagating medium. When you see evidences of new growth, or when roots have developed, dig under it with a spoon and remove it for potting. (Here is the test to determine if roots have developed: Pull on the cutting, very gently of course. If you feel resistance you know it has roots which are holding it down.) Pot your new plant very carefully in soil that is suitable for it; and please, don’t add fertilizer to this soil.

For stem cuttings, and most other methods of propagation, there are now certain hormone rooting preparations. They speed up rooting, make it more certain, and help to develop larger and healthier root systems. Be sure you get the correct type for softwood cuttings, or indoor plants. In using these new hormones, follow the directions on the package carefully.

Leaf Cuttings

It is a well-known fact that African violets will reproduce themselves from a single leaf. However, it is not so well known that there are dozens of other plants that will do the same. For example, more than once I have taken a succulent leaf, laid it out flat on moist sand, and had it grow roots and a small new plant. Leaves of peperomias, and many other plants, can be cut, with or without a piece of stem, and will grow bushy new plantlets. Some kinds of begonias will send out roots from the end of the stem, or new plants from the point above where stem and leaf join.

Except for some succulents, leaf cuttings are usually inserted with their stem ends in a moist propagating medium, with their leaves standing nearly upright above. (Again, you are safer if you have a propagating box, even though it be a crude one.) When they are well rooted and the new plants are of fair size, the cuttings are potted with the old leaves intact. The parent leaf is removed only when the new plant is strong enough to grow on its own. Of course, in the case of African violets, where more than one plant is produced at the end of the stem, the babies must be separated and each put into its own pot.

Root and Rhizome Cuttings

Sections of roots are sometimes cut to propagate house and greenhouse plants, but the practice is more common with hardy garden plants. But pieces of thickened, stemlike, or rootlike rhizomes can be taken from many types of indoor plants. Rhizomatous begonias, and rex begonias of rhizomatous habit, are familiar examples. Each piece of rhizome should have at least two, but preferably three, “eyes,” or scars from which leafstems have grown. The piece is placed half in and half out of the moist medium in the propagating box. Roots grow from the bottom down into the medium; stems and leaves shoot up from the eyes on top.

Layering

There are two general methods of layering, and in each case the plant is completely rooted before it is cut away from the parent. In “air layering” a thick stem, or cane, is slit, wrapped with moist sphagnum moss, and enclosed in plastic until roots are produced. This method is usually practiced on large, overgrown plants such as dieffenbachias, and truthfully is not necessary, or practical, for most miniatures.

But ground layering is a safe and sure way to propagate almost any plant with lax stems, and is particularly useful on temperamental plants such as some miniature ivies, which are reluctant to strike roots on stem cuttings. It is very simple. Just pin down the stem, not too far from the growing tip, in the soil beside the mature plant. If you like, you can put it in a pot of its own and thus be one jump ahead by having the roots where you want them. I usually steal a hairpin out of my “bun,” but a section of wire bent into a U will do. When the stem has rooted, cut it off on the side next to the parent plant. Unless it is already rooted in a pot, dig it out and plant it.

Division of Crowns and Roots

One African-violet plant may grow several crowns, or main stems complete with rosettes. Since single-crown plants usually are more shapely and bloom more abundantly, the extra crowns can be cut off and rooted like ordinary stem cuttings. This is one of the more popular methods of dividing an old plant and getting several new ones from it.

Some plants will eventually make such dense, bushy growth that they not only look obese and unattractive, but are prey to all sorts of rot. Root division not only gives these plants a new lease on life, but also provides several new plants. Remove the overgrown plant from its pot, and very gently, try to split the matted roots and stems into separate sections. Do this with your fingers and not a metal instrument. If you work slowly and with care, several will most likely pull free. If you can’t do it with your fingers, you may have to resort to a clean sharp knife, in which case cut down past the stems and through the roots, making several separate sections. Discard any damaged leaves. Pot up the divisions, and keep them shaded and protected for a week or so until they recover from the shock.

Runners, Stolons, and Offsets

Many plants are continually propagating themselves by producing new plants in clusters around the old ones, sometimes at the ends of underground stolons or above-ground runners. Saxifraga sarmentosa was named “Strawberry begonia” because it continually produces new plants on runners, strawberry-style. Episcias and chlorophytums are other examples.

Any of these offsets make new plants easily. Pin them down in soil, give them time to root, and then cut them off and insert them in a propagating box. Next, you pot them. Sometimes you’ll find the roots have already formed and the new plant is ready for potting and you didn’t even suspect it.

DESCRIPTION OF HOUSE PLANTS

Some pages back I told you that the question asked of me most frequently is “How often should I water plants?” A close runner-up is the question, “Where can I get out-of-the-ordinary plants?” Believe it or not, that question is easier to answer. Local florists and greenhouse people often have plants tucked away—something exotic and special. Most of the people in the industry cherish these plants and are hesitant to part with them to run-of-the-mine customers. But if the person is a genuine plant-lover, a sale can usually be made, even though it is a reluctant sale. Just demonstrate that you are vitally interested and you will be surprised at what you can buy. Try it.

I have a number of catalogues from mail-order suppliers in all parts of the country who carry unusual plants, and in a variety that increases year by year. Do you know where I came upon their names?—from small advertisements in horticultural magazines. Read those small ads. Often the advertiser is so small, and so specialized, that he can’t afford too much space. But he has the treasures you want.

Mail-order plants are naturally young and small. Large plants are too difficult to pack and ship for any distance. Plants that are small usually cost less, and you have an extra dividend in the pleasure of seeing them grow to maturity. You would be amazed at the progress that has been made in packing and shipping in the past few years. Plants that I have ordered recently have come through the mails in from excellent to perfect condition—even plants from the Pacific Northwest. You simply unpack them—carefully, I’ll admit—water them if necessary, and keep them out of hot, bright sun and draft for a few days until they are acclimated to their new surroundings. Should any plant seem weak or mildly injured, pop it into the propagating box and usually it will be back on its feet again in a few days. If the damage is too serious, report it to the post office, the express company, or the shipper. I have yet to register one of these complaints.

I have been general in the preceding pages of this chapter. Now I will be more specific and offer a list of plants and their growing requirements. All of the following plants can be grown in the greenhouse. But given proper light, humidity, and/or other special care, they can be grown in the house where you live—even the most delicate types. The information on culture is abbreviated, but consistent use of the same terms, I feel is justified. The following are used in the sections on care under each plant.

Full sun

The sun actually falls on the plant for most of the day.

Partial sun

The sun touches the plants for only a few hours in the early morning or late afternoon in summer, but for longer periods in winter (tropical areas excepted).

Little or no sun

Bright daylight is sufficient to keep some plants healthy.

Temperature

Any figures that are quoted are for daytime. Night temperatures can usually drop about five degrees. (Cool is 40 to 60 degrees; moderate, 50 to 70 degrees; warm, 60 to 80 degrees.)

Humidity

This is noted if the plant needs more than average humidity (50 per cent).

Soil

The plant may prefer a potting mixture that is humusy, extra-rich in organic matter; average, like the potting soil I have described on other pages; sandy, with an extra ration of sand, or a similar substitute. Or it may be epiphytic and grow in some suitable medium such as osmunda fiber or sphagnum moss.

Dry

Let the soil dry thoroughly before watering.

Moist

Water when the soil in the top of the pot feels dry to the touch.

Wet

Never allow the soil to dry out.

Methods of propagation are also summarized and, if possible, listed in order of preference. The terms are the same as those used in the sections on propagating house and greenhouse plants.

For most plants, there are short notations on special uses for which they are especially suited, i.e., growing under artificial lights, dish gardens, model landscapes, terrariums and other gardens under glass. Included also are some small tropical trees and shrubs for the small greenhouse. Among the precious miniatures described in Chapter 17, varieties suitable for forcing are so noted. Forcing procedures are also covered.

Abutilon hybridum savitzi Malvaceae Flowering Maple

Delicate tropical shrubs with thin, soft, maple-shaped, dove-gray leaves lavishly splashed with creamy white, and sometimes white all over. (I’ve never seen it produce the typical dangling lantern flowers.) It grows slowly, keeps plump and bushy, and is content with a small pot for several years.

CARE. Full sun, moderate temperature, and average soil kept constantly moist.

SPECIAL USES. Artificial light, dish gardens, model landscapes, terrariums.

Achimenes Gesneriaceae

A large group of utterly charming plants related to, and grown like, African violets—except that their scaly rhizomes (like minuscule pine cones) are completely dormant in winter. Most have velvet-soft leaves and all produce an overwhelming display of tubular flowers flaring wide-open at the end. None grow to great size. A single rhizome would probably be happy in a two-inch pot; several are usually planted together for a bigger show. The following are among the smallest varieties, upright unless otherwise noted.