A NEW COMPOST FORMULA
By C. E. L. GILBERT
From when I first commenced growing cacti I have felt the need for an improved soii compost ; some very good growing mixtures were known, but they, in my judgment, all fell short of perfection.
Like many another collector and grower, I have given much time to experiment and grown plants in varied soil mixtures, but not with much success—till, almost by chance, I made what seems to be an interesting discovery. The nutritive side of a good compost, to be sufficient for our plant needs and improvement, lies in the non-nutritive side, i.e., sand, brick dust, charcoal, lime, etc., the portion responsible for keeping the whole in a healthy condition. I concentrated thereon and, some years ago, happened to incorporate an amount of breeze granules, the residue of a quantity of breeze blocks I had used for construction purposes, into the remains of compost in use at the time, enough for a ten inch half pot. The larger pieces I used as crocks. Into this half pot was planted a number of small pieces of a badly decayed plant of M. elongata Stella aurata with which I had despaired of doing anything, they had refused to root in sand and I had a mind to destroy them. They were given no further thought till the following spring when, upon turning them out, I was amazed to see the amount of roots formed, furthermore, the compost disintegrated, falling completely away, with the roots quite undamaged, forming tresses about ten inches long. The cuttings had also made considerable growth and now looked very healthy.
I carefully examined the compost and noted its pleasing texture, also it was very clean and fresh looking, just the kind of soil to use again for re-p!anting.
During the ensuing spring and summer, following up this encouraging result, batches of various cuttings and plants were potted up in compost with varying amounts of breeze granules, with continued success, in fact, I have yet to find varieties of cacti or succulents that do not respond well.
This added breeze gives benefit to all sections of plant growth, including seed raising, in fact, we now incorporate this breeze in varying amounts into all our plant composts. I can only conclude that we have a greatly improved medium to the previous popular use of brick dust, etc. I find that any manufacturer of breeze building blocks, made with clinkers and cement, has large quantities of broken blocks and dust that they are only too pleased to get rid of. These blocks, themselves, are quite inexpensive, but get only blocks that break up easily, those of poor quality that crumble, others are quite useless.
The following good qualities I have noted in compost with added breeze of from half to one third.
Absorption of mixture perfect. A three-inch pot of dry compost, placed in a shallow tray, quickly absorbed water, the compost acting as a sponge, the excess quickly drained off upon removing pot from tray, the pot dried off in the next few days.
Effect upon soil. All soils perfectly clean and healthy. Marked freedom from caking. Pots of growing plants, banged gently down on a hard surface, disintegrated the soil completely and allowed ample air into the soil. Re-potting. The soil crumbles upon touch and completely falls away from the roots. Where pots were root bound the roots uncurl and are quite undamaged, little dead root noted.
Expense is negligible.
Soil surface. Little caking and freedom from moss and algae.
Plant growth. Improved growth with all plants, the colour and vigour of spines much improved.
Effect upon health of plants. I have cut my losses to less than ten plants, including one-year-old seedlings, in quite a hundred thousand plants. This winter all my most rare and valuable plants look well including the difficult ones, i.e., M. plumose Ariocarpus, various Pelecyphora, etc., especially Parodies, of which I have a great many, a marked freedom from plant or root rot.
Propagation. Cuttings and seed do very well, rooting greatly encouraged. All my seedlings, though seeds were planted late last year, are more advanced than any previous batch planted.
I warn cacti enthusiasts who wish to experiment to go cautiously until they are satisfied, as I have no assurance that the chemical contents of breeze does not vary with the various makers. I can only speak for my own source of supply.
The lecture " Outdoor Culture of Plants," on May 12th, will be given by Mr. A. Boarder.