This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
A correspondent asks for instruction in growing pine apples. I have never thought it requires as much skill - or at all events not more - to grow pine apples than to grow tomatoes under glass. If "Inquirer" is a gardener who has not had experience in the cultivation of this fruit he need not experience any serious difficulty in the matter. All things considered, we prefer low span roofed houses, so that the plants may have light sufficient, and be not too far from the glass. They must have bottom heat, and the most convenient, perhaps the most economical method of supplying it is by hot-water.
A hot air chamber under the bed, heated by pipes, is the best way, and the one least liable to accident. The bed in which they are grown should be not less than four feet deep; this depth is sufficient to cover the largest pot with the plunging material if the pines are thus grown, and it also gives a sufficient depth of soil if the plants are planted out, which is the preferable way of doing it.
The material for growing them in, if planted out, may be about as follows: say about six inches of drainage, which may consist of broken brick, &c; over this a layer of sod, grass downward, cut about the same thickness as for sodding; then about two inches of half-inch and coarser bones; over that another layer of sod three or four inches thick, which will constitute a kind of backbone to the bed. Prepare the compost of sod chopped into pieces three or four inches square, mix through it charcoal and broken stone of the size of a shellbark nut and smaller - but no dust - also broken bone liberally. Fill the bed to within eight to ten inches of the top. Secure clean healthy young plants of an approved variety or varieties, and plant in the bed up to the lower leaves about three feet apart. If a large variety - as the Providence - be grown, give at the least another foot of space to each plant. Press the surface smooth, and water with water as hot as the hand can bear in it if the weather be cool.
If the bed is mulched it will keep the moisture more uniform and reduce the trouble of watering to a minimum. A good temperature is 75°, although I have often raised it considerably higher during summer; but I would not like the heat to fall much below that mark for any length of time during the season of growth.
To obtain good, strong, stocky growth keep the bottom heat well up; 90° is not too high. Water liberally with liquid manure during the growing; give air in the morning before the sun has risen too high; close early in the evening, dampening the beds, walks, etc, at the same time. Gills and suckers should be removed to throw the strength into the fruit. As soon as the fruit commences to change color, withhold water and maintain a dryer atmosphere. If the fruit be ripened in cold weather, cut a few days before fully ripe and place in a higher temperature; it will improve the flavor and prevent early decay. When the pine apple fruits it throws up suckers; these are sometimes rooted before the fruit is cut; but whether they are or not is immaterial, as they root very readily. When the fruit is cut remove the stools, separate the suckers and plant singly, as at first, potting a few of the best suckers to insure keeping up a 6tock. This is the whole round of pine apple culture. It will be seen that a very rich compost is not recommended, - it is better to supply it in a liquid form when needed.
To summarize, - start with good, clean, healthy suckers, don't injure the leaves by any means during the period of growth, be careful not to check it by any sudden change, as of temperature, drouth, etc. Mulch in the late fall to obviate the necessity of much watering during the winter, keeping the plants at that season in a medium state of dryness. Maintain an equable temperature, when fire-heat is necessary, of 55° to 60°, bottom heat 10° higher, allowing a rise of 10° by solar heat whenever convenient.