Old And Sold Antiques Auction & Marketplace
Antiques Digest Browse Auctions Appraisal Home

Old And Sold Antiques Digest Article

The Soil in Which Your Plants Live

[Introduction]  [Planning Your Garden]  [Air, Light, And Temperature For Plants]  [Soil For Plants]  [Flowerpots]  [Potting, Watering and Feeding]  [Insects And Ailments]  [Why Some Plants Die]  [Hydroponics or Checmical Gardening]  [Kids And Gardening] 

"Doing things in good time is the main secret of successful gardening." AUTHOR UNKNOWN.

Most house plants are grown in potting soil containing enough sand to keep it porous and enable water to drain through it readily, enough garden earth to give it firmness, and enough decayed vegetable matter to keep it damp between one watering and the next.

Standard Potting Soil

A good potting soil would result from mixing thoroughly:

6  parts garden earth, loam, or topsoil

3 parts sand

1 1/2 parts humus, compost, or decayed leaves

1 1/2 parts peat moss, teased out by hand and rubbed into small fragments, but packed down again for correct measure

1/2 part bonemeal

12 1/2 parts in total

(These are parts by measure-cups, milk bottles, pails or the like.) If you own an outdoor garden you should maintain a Compost heap which will receive all autumn leaves you rake up, lawn clippings, the weeds you pull, clean vegetable refuse like carrot tops and outer lettuce and cabbage leaves. No diseased or insect infested materials may be used; burn them instead.

When the heap has decayed to become a black mold it may replace part of the humus and peat moss in the formula above; if necessary, it may replace all of both. Decay can be hastened by turning the heap every month in summer or by using one of the disintegrating materials sold for the purpose like Activo or Adco.

Standard potting soil for most plants may be made of: 6 parts of garden earth, 3 Parts of sand, 1 l/2 parts each of humus and peat moss, 1/2 part of bonemeal- 12 1/2 parts in all.

The sand should be the kind used in mixing concrete, and a builders' supply house describes it as coarse, sharp silica sand. Most supply houses sell sand in small bags for home mechanics, and fifty-cents' worth or so should last you some time. In addition to mixing it with soil, the indoor gardener uses sand alone in his propagating box to enable cuttings to produce roots. When you get your sand home, spread it in a shallow heap and pour several gallons of water onto it to wash impurities from it. Or put it in a pail with water, stir and pour off the water, repeating several times. After cleaning it, let the sand dry.

An artificial sand made from mica is obtainable under the name of Vermiculite. Its particles are angular and, similarly, it may be used for mixing with soil or alone for rooting cuttings.

Earth is best taken from a part of the outdoor garden where plants grow well; take it only from the top three inches. You have no garden? Then buy some dirt from a nursery, florist or farmer; or put a clean ashcan in back of your car and half-fill it from the country. Get dirt from a cultivated field, but try to get a few clumps of grass along with it. With the grass sheared into small pieces, the underlying root-filled three inches becomes the chopped sod sometimes referred to in garden books. In some English books you will find "top-spit loam" advised for some garden purposes. This is dirt along with grass roots from a heap of turves which the gardener has stripped from a pasture or lawn and stacked to decay for use in his greenhouse. Chopped sod and top-spit loam are valuable additions to garden dirt in making up your potting-soil mixture, and either or both may be used in place of one-half the garden dirt ingredient.

The earth that you buy or beg must be actual topsoil, which you can make sure of by close examination. If it is suitable you should find remains of past generations of plants all through itpieces of leaves, stems, roots and flower fragments. The earth itself may consist mostly of sand, easily running through one's fingers: this we would call a sandy soil. If it has some cohesive properties but is still very gritty we would call it a sandy loam. If we could squeeze a damp handful into a lump, which readily breaks down, however, it would be a clay loam. If compressible into a pasty lump that retains its shape, it would be a clay soil. Midway between a sandy loam and a clay loam is a medium loam, which is gritty but will not retain its shape when squeezed.

Should your garden dirt be taken from a valley floor or a drained swamp bottom which is being used to grow lettuce, onions or celery, it may naturally have so much organic matter as to be nearly black, and we would call it a muck soil.


We may amend our potting-soil mixtures for ferns and for other plants that require a fibrous medium by adding i part each of extra humus and peat moss.

When we use this potting soil for acid-loving plants, we can add 1/4 part of aluminum sulphate. Test the soil from time to time and, whenever it shows pH 6.5 or higher, whiten the surface of each pot with additional aluminum sulphate and work it just under the surface with the kitchen fork.

For cacti, let us use twice the sand; or instead of additional sand we might add small pieces of crushed rock or broken flowerpots in an equal amount.

For lime-loving plants, add to the appropriate formula 1/2 part of pulverized limestone. Test the soil from time to time and, whenever it shows pH 7.5 or less, whiten the surface with pulverized limestone; work it just under the surface with a fork.


For a medium loam use the standard potting soil mixture described above, but if your earth is a sandy soil, sandy loam, clay loam, heavy loam, or gritty or pasty muck, use the following variation:

Sandy Soil: 6 parts of the sandy. soil earth, 1 1/2 parts each of humus and peat moss, 1/2 part bonemeal, 9 1/2 parts in all.

Sandy Loam: 6 parts of the sandyloam earth, 1 1/2 parts of sand, 1 1/2 Parts each of humus and peat moss, 1/2 part bonemeal, 11 parts in all.

Clay Loam: 6 parts of the clayloam earth, 4 1/2 parts of sand, 1 1/2 parts each of humus and peat moss, part bonemeal, 14 parts total.

Heavy Clay: 6 parts of the heavyclay earth, 6 Parts of sand, 1 1/2 parts each of humus and peat moss, 1/2 Part o f bonemeal, 15 1/2 parts in all.

Gritty Muck: 6 parts of the grittymuck earth, 4 1/2 parts of sand, 3/4 part each of humus and peat moss, 1/2 part bonemeal, 12 1/2 parts in all.

Pasty Muck: 6 parts of the pastymuck earth, 6 parts of sand, 3/8 part each of humus and peat moss, 1/2 Part of bonemeat, 13 1/3 parts in all.

When your garden earth is a clay loam or a clay soil you had better use a soil-conditioner like Krilium or Soiloam, which will cause the clay particles permanently to coalesce into larger granules. Buy a minimum-size container and follow directions.

The ingredients for a potting-soil mixture should be fairly dry; if they are in a muddy condition, wait a few days. Purchase a soil-testing kit and try every new batch of potting soil; if it proves to be acid, with a pH rating of 6 or less, add 1/2 part of ground limestone rock or pulverized limestone for most plants. If it is alkaline, omit the bonemeal and use 1/2 part of aluminum sulphate instead. Should it prove to be low in nitrogen, add 1/2 part of castor pumace. If it is low in phosphorous, use 1/2 part of superphosphate; if low in potash, use 1/2 part of powdered tobacco.

Most plants thrive in a neutral soil, pH 7, including anemone, asparagus, astilbe, carnation, chrysanthemum, daffodil, dahlia, gladiolus, English ivy, geranium, hyacinth, narcissus, pansy, primula, ranunculus, rose, tulip, viola and zinnia.

For most others, use the formula as is; but for those preferring an acid soil, which is pH 6.5 or lower, increase its acidity by omitting the 1/2 part of bonemeal and substituting for it y part of aluminum sulphate. Acid-soil lovers include azalea, devil's walking cane, ground pine, lily-of-the-valley, insectiverous plants.