This section is from the book "The Gardener's Monthly And Horticulturist V21", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Around this neighborhood where shrub or tree planting is to be done, beds have to be made expressly to insure success. We have here three beds of Rhododendrons, and prepared a fourth last Fall for planting soon; the beds now planted are a great success, having been well prepared at first.
In making the beds we take off the surface sod and any good soil, laying it aside, then take out the gravel three feet deep; we then throw the surface sod and soil in the bottom, turning the green side down.
The compost used is bog or swamp peat, not dead sour stuff three or four feet deep, but the fibery sod of the surface, a spade depth, where ferns and native Azaleas grow. This is brought home and chopped up tine, throwing aside all dead wood or large roots •, when all is gone over once we then add a good load of well rotted leaf mould to six loads of peat, and a load of sharp river sand is added, and the whole is turned three or four times to insure thorough mixing, likewise helping to pulverize the whole. We proceed next to fill the bed, beginning at one side, keeping the roughest towards the bottom and treading all down firmly as we go along, leaving the bed rather higher than the surface of the ground, as it will settle a little; the bed is then ready for planting.
As regards varieties, all the Catawbiense var-ities are hardy, and can be had from almost pure white to dark purple. In making a selection it is best to pay a visit to some nursery when they are in full bloom and choose for yourself. Young stocky plants are preferable to old woody ones; give plenty of room when planting as they soon fill up.
As the soil will be exposed to the sun for some time before they are able to shade it; give a mulching with some litter to prevent drying at the roots. Should a continuance of dry weather set in the leaves droop, their edges roll backwards, then water is wanted and must be given to insure success the following season. In answer to a correspondent in the February number as whether to plant in the shade or full sun? I say plant in full exposure to the sun, and they will stand the Winter far better; the time to shade is from November to March, or from the time severe weather sets in until it is past; this is necessary in Massachusetts, and pine boughs I find answer the purpose well.
F. H., New Bedford, Mass., asks: "Should rhododendrons be planted where in the summer, they are shaded a part of the day, or where exposed to the sun all day. Give distance apart for planting".
The essential part of rhododendron culture is to have cool earth to grow in - earth that is never of a high temperature, or that is ever quite dry or very wet. The little hair-like rootlets like cool, moist air about them, but not water; with this, sunshine or shade for the foliage is but a secondary consideration. Some of the best rhododendrons we have seen have been in the full sun; but they soon go back in the full sun," if the soil is apt to bake - that is, get hot or dry.
Usually, in clay soils, the earth has to be prepared especially for rhododendrons, by mixing with it such as may help it to be porous and cool. This is the reason why peaty soil is often employed. The spongy character retains both air and moisture, and keeps cool. But if the soil has these capacities, peat or earth of that character is not essential.