Potting And Repotting House Plants
( Originally Published 1923 )
The best time of the year to repot house plants is in the spring (April or May), or when new growths start. Only in very exceptional cases do house plants need repotting during the winter; this is particularly true of palms, ferns, rubber plants, etc. These plants are then resting or are making very little growth, and meddling is positively dangerous to their lives. The average amateur gardener does not realize this, and, although the plant is in a good, healthy condition, he becomes very much worried because it is not making new growth. Then he will repot the plant, putting it in a larger pot, and nine times out of ten the plant becomes sickly and often dies in a few weeks because of the shock received and the inability to make a new root system rapidly, and so take hold of the new soil.
FEEDING vs. REPOTTING
Soft-wooded plants, like geraniums and coleus, I would much rather feed with liquid fertilizer than repot during the winter; although, if the plants are growing, they may be shifted to slightly larger pots without injury. Should you desire to repot the plants, do so before the roots circling about the inside of the pot become woody; after they have matted but while still white and succulent.
HOW TO "KNOCK OUT"
To remove the plant from its pot, take the pot in the right hand and place the stem of the plant between the index and middle fingers of the left hand; then invert it and strike the edge of the pot sharply against the edge of the bench. The ball of earth and roots will slide out easily, unless the earth is dry; in that case, before attempting to remove the plant, immerse it in water until the earth has become damp.
Now, with the right hand, disentangle and spread out the lower half of the mass of roots. If part of the ball of earth crumbles away, it does not matter. Then place enough soil in the new pot to bring the plant in about the right position — that is, with the surface (which should be loosened up) of the old ball about half an inch to one inch, according to size, below the rim of the pot.
The potting stick will be useful in firming the soil.
When removing palms, rubber plants, and other comparatively large-rooted plants from the pots, the roots will be found matted together in circles. If possible, without injuring the roots, remove the old drain-age. This will leave a large hole in the ball. Before putting the plant in the new pot, fill up this hole with soil; otherwise it will allow the water to drain away too rapidly, and the interior of the ball becomes too dry. Some-times the roots are so matted that it is impossible to remove the drainage.
POTTING UP CUTTINGS AND SMALL PLANTS
Cuttings and seedlings are usually first potted up in thumb pots (two-inch), from which they are shifted to larger pots as soon as the pots have become filled with roots. The soil used in filling these small pots must be free from all lumps. The better way to pot these small plants is to hold the cutting with the left hand and with the right hand fill in the soil. When the pot is full, firm the soil with the thumbs and then give the pot a sharp rap on the bench to settle the soil.
Another way to pot up cuttings (but which I believe is not so good as the way already described, because the roots are much more liable tO get bunched together) is to fill the pots with soil and then make a hole in the soil for the roots, after which the soil is firmed. This is also a slower method.
LIFTING IN LATE FALL
When potting plants in the fall which have been outdoors in the flower beds all summer, select only stocky, healthy plants.
Dig them carefully so as to secure as many roots as possible. If the soil is clayey, it must be neither so wet that it is muddy and the roots cling together, nor so dry that the dirt crumbles entirely away from them. The right condition of soil can be obtained by a thorough watering at least five hours before potting.
If the plants are growing in sandy soil, it is better to have it rather dry, for then more of the working roots can be saved than if it is wet.
After potting thoroughly water the plants and set them in a shaded place. Syringe the foliage several times a day until the roots have taken hold of the new soil; but under ordinary conditions, the soil will not again need watering until the new roots have been made. As soon as the plants have taken hold, gradually inure them to direct sunlight.
MAKING WORK EASY
Potting is done best on a bench which is about waist high. For the window garden a portable affair will be found the most satisfactory. An old kitchen table on three sides of which some boards, about a foot wide, have been fastened to keep the soil from failing upon the floor will serve the purpose.
The best way to work the soil in among the roots is to hold the plant with the left hand, put a little soil around the roots, and work the plant up and down a little. Put in some more soil, and tamp it down with a potting stick. It is possible to get the soil too firm, so use the potting stick with moderation, and be careful not to strike the roots.
A potting stick is usually made from a piece of pine about a foot long; an inch wide, and an inch thick, with the corners and ends rounded off. A piece of a broom handle is sometimes used.
If the soil contains many lumps or coarse pieces of sod (as sometimes happens when the sod is not completely rotted), screen them out before potting. This will be necessary if the pots are small — six-inch and smaller — with larger pots it will make but little difference. The ordinary ash sieve is just the thing for this. Or you can make a sieve from a small box, say about eighteen inches square, cut off at a depth of three inches, and the bottom covered in with wire screen netting which has a quarter-inch or three-eighth-inch mesh, and sift the dirt through this. Save the coarse material, it will be useful when potting.
In the bottom of each pot put some coarse drainage. Broken pots are usually used for this, but coal clinkers or stones are just as good. Use whichever is the handiest. Broken charcoal is very good also. The larger sizes of pots — three-inch and up — need crocking; use from a quarter of an inch to two inches of drainage according to the size of the pot. If you use broken pots, put the pieces in with the convex side up; the crocks will fit better. Over this drainage put some of the coarse screenings to keep the finer soil from washing down through. If there are no coarse screenings, use sphagnum moss.
THE FALLACY OF LARGE POTS
Don't work on the principle that the larger the pot and the more soil, the thriftier the plant. It is not the amount of food available, but the amount assimilated, that counts. As a rule, any pot which seems to be in proportion to the plant, holding soil enough to keep it . from being top-heavy, will be sufficiently large. Most amateurs make a mistake in the size of the pot, using one a size or two toO large. It is very easy, indeed, to over-pot a plant, strange as it may seem, and really nothing in the plant's life can be more disastrous than an overlarge pot. Nine times out of ten the plants will be over-watered and the soil become sour.
Pots may be obtained at almost any hard-ware store. Buy the heavier ones, as the very thin ones now manufactured by some firms dry out too quickly. Soak new pots in water until they get through "bubbling"; otherwise, the soil of the newly potted plants will dry out too quickly. If the pots are old and green with algae, clean them by scrubbing them with sand and water, for the "green" makes them less porous, and old earth dried on the inside surface interferes with the new root-growth.
If potting is to be done with soil which has been mixed for some time, determine by the method described in the previous chapter whether or not it has sufficient moisture. If it has not, spread the soil out thinly on the bench, water it, and then turn it a couple of times to evenly distribute the moisture as directed.