Indoor Cactus Garden
( Originally Published 1942 )
IF it is intended to establish a cactus garden in the colder or more humid sections of the country, it is well to remember that a very great many of the members of this group of plants are natives of arid, tropical or semi-tropical countries. Their age-long struggle to adapt themselves to the trying conditions of their environment has developed a highly specialized physical structure. It should not be expected that . these plants may be torn from their native home and immediately readjust themselves to an entirely new set of conditions never before experienced by them in all the centuries of their development. We do not expect monkeys from the tropics to survive when thrust into our rigorous climate unless they have adequate protection and food closely approximating their native diet. Salt water fish are never called upon to ad-just themselves to fresh water and temperatures other than those to which they are adapted.
Plants should receive the same consideration as animals in this respect. So it is that those persons, living in a colder climate, must protect their plants from freezing temperatures; those of us who live in humid sections must see that they do not get too much moisture, and all must be considerate of their diet, that is, furnish them with proper food.
Only a favored few have hothouses avail-able for their plants where temperatures and moisture may be regulated. Others must resort to the use of flower pots or window boxes.
Flower pots are usually very satisfactory because they may be so easily moved from one place to another as the requirements of the plants demand. The following suggestions may be found helpful in establishing and maintaining a cactus garden of this character:
It must first be decided what size flower pot to use for a certain plant. The size of the pot to be used is rather an important matter, and the beginner is hardly satisfied with the bald suggestion that he select a pot suitable for the plant considered. But definite suggestions are difficult because so many conditions enter into the problem.
Cacti, as a general thing, are not as rapacious feeders or as rapid growers as are many other house plants, and, therefore, do not require so much soil in proportion to their size as do such plants. Cacti vary consider-ably in the relative size of their root systems and their soil requirements, and these variations should be considered. You will be reasonably safe, however, if you use pots for your globose species that are twice the diameter of the plant. Give a four-inch pot to a plant that is two inches in diameter. Allowance must be made for the height and general size of those plants which grow taller and more cylindrical. A twelve-inch pot may be expected to care for any plant of this type that is from two to four feet in height.
The size of pots here suggested lean toward the size of generosity. Many people grow their plants in much smaller pots, but observations will prove that, although their plants may remain healthy, they sacrifice growth and possibly flower production.
The soil to be used for the plants is the next important consideration. We have been taught all our lives that the richer the soil, the more humus it contains, the more vigorous will be the plant growth. It is quite natural to wish to give our cherished cacti the very best soil available—nothing is too good for such treasures, in our estimation. But we must remember that these plants are not used to such prosperity, and that many beautiful specimens have fallen victim to the "kindness" of a loving but misguided owner. These plants thrive in poverty, but die in prosperity.
The author does not know of any better suggestion as to the type of soil to use than that given by Ernest Braunton in his article, "Best Soil for Cactus," in the August, 1929, number of the Journal of the Cactus and Succulent Society of America. The mixture recommended is as follows :
"One-half sharp sand, one-fourth good peat (available at any store selling florists' supplies), one-fourth good black loam; to this should be added one-twentieth as much pulverized charcoal. There should be added a small percentage of powdered limestone or slacked lime for such plants as do well in the limestone areas." Other modifications to suit the needs of special plants will be worked out by the grower as his experience increases, but this mixture is a good reliable one with which to start.
The bottom of the pot should be covered with small stones or broken bits of pottery. This is to keep the soil from packing so tightly over the holes in the bottom of the pot that there cannot be proper drainage. A little coarse sand or fine gravel may be added to the broken pottery in order to avoid undue air spaces.
Before a plant is placed in a pot, the roots should be examined very carefully. All roots that are shriveled, dead or show indication of being rotted should be cut back to clean, healthy tissue. If all of the roots are in bad condition, cut them all off. If the base of the plant is unhealthy, cut that off too, and plant what you have left. This advice may seem strange to you and contrary to all recommended practice in the handling of other plants, but remember that you are dealing with a unique group of plants. When you plant a cactus, that plant should be free from all diseased tissue. The cacti have remarkable ability to survive major operations if protected from infection, but they are extremely susceptible to dis-ease. The tissues are so soft, spongy, and full of moisture that they offer an ideal condition for the rapid growth and spread of fungous diseases.
The knife that you use in an operation on your cactus plant should be sterile, and it should be sharp. The sharper the knife, the greater will be your success. Torn or raggedly cut tissues heal slowly whether they be animal tissues or plant tissues.
Any considerable cut in the tissue should be exposed to the direct rays of the sun for a period of from one to five days, according to the extent of the cut surface. The rays of the sun sear or close the exposed layer of cells. This prevents the loss of moisture, helps to sterilize the surface, and, by closing the cells, prevents the entrance of bacteria and fungus.
It is interesting to know just how far one may go in this matter of surgery. There are several phases of surgery which will be discussed a little later, but a description of the experience of the author in preparing one particular cactus for planting may be interesting and helpful.
A beautiful specimen of the barrel cactus (Ferocactus wislizeni) was sent to the author from New Mexico. The specimen weighed over four hundred pounds, and was planted in a tub so that it might be kept on display at the museum. It did very nicely for a long time, and then it stopped growing. At last, it fell on its side, and seemed to be hopelessly dying. Examination showed that rot had gained entrance at the base of the plant. It was decided to perform a major operation, and the basal third was cut off with a saw. But the rot had penetrated still farther up into the plant. After this rotted center had all been cut out, there was left of the plant only an outside shell that was about three inches thick. The entire cut surface was exposed to the morning sun for five successive days. The soil in the tub was changed, and the convalescing plant was then replaced on it. One year after this operation, the plant appears strong and vigorous, and, at this writing, has forty-two buds which will soon be opening to delight museum crowds with their beauty.
Repotting is an operation governed by the same principles as those followed in original plantings, and for that reason will be discussed at this time.
Some growers feel that potted plants should be given new soil and re-potted each year irrespective of their apparent condition. Such a practice has some few advantages, but the author feels that such frequent re-potting will not be necessary if the suggestions already given as to size of pots, kind of soil to use, drainage, preparation of plant before potting, etc., have been care-fully followed.
It is a kindness to leave the little plant undisturbed so long as it appears vigorous, healthy and happy. Of course, plants that have become too large for their container should not be neglected until they show ill effects of the crowded condition of their roots. A larger pot should be prepared according to previous directions. A cone shaped hole about the size of the smaller pot should be made in the soil of the larger pot. A. knife should be run around the inside of the smaller pot containing the cactus in order to loosen the soil from the sides of the pot. If the pot is then turned upside down on the hand and gently tapped on the bottom with a knife, the entire contents will come out without breaking apart and disturbing the roots. The soil and roots may then be placed in the cone-shaped hole pre-pared for them in the larger pot, and the new soil pressed in about them.
It is quite a different matter, however, when a plant shows a sluggishness of growth, a paucity of bloom, sickly color or other symptoms of an unhealthy condition.
If there is no visible indication of an explanation of the condition on the upper part of the plant, there should be no hesitation in taking up the plant. All soil should be washed from the roots so that a careful examination may be made. The procedure to be followed is then exactly the same as de-scribed for the making of an original planting. Entirely new soil should be given the plant after it has been treated—the old soil should never be used a second time.
These simple suggestions faithfully followed will assure the amateur of the utmost delight to be derived from a healthy family of cacti.