which the name was initially applied was Primula vulgaris.
Its foliage is like that of the polyanthus, but its single-stalked flowers easily distinguish it from the clustered inflorescence of its hybrid.
Occasionally, however, some of the modern strains of Primula vulgaris tend to produce small low clusters toward the end of the blooming season.
The color range is not quite as extensive as that of the polyanthus, but the yellows, pinks, and crimsons are good, and the shades of blue are particularly outstanding. Because of the habit of blooming, the plant seldom exceeds a height of 8″ inches.
Nurserymen in the US usually list this species as acaulis, although Vulgaris is the correct name.
Even more dwarf than the true primrose is Primula Juliae and its hybrids, the Juliana primroses. Some of these are cushion-like in form and not over 2” inches high. Others are stalked but not more than half the height of the polyanthus.
Named varieties are available, and their color range continues to expand with further hybridization.
Strains of the bear’s ear cowslip, Primula auricula, have been highly prized as a show flower in Europe. Still, only the comparatively rugged “garden auricula” is practicable for cultivation in most parts of this country. Its smooth, succulent leaves are quite distinct from those previously mentioned groups.
The fragrant purple, red, yellow, or brown flowers are borne on stems intermediate in height between the polyanthus and the true primrose. It will get along with a little more sun and a little less water than most of the other primulas but, in my experience, is somewhat more prone to rot and attack by slugs which seem particularly partial to it.
Therefore it requires very well-drained soil and some protection from slugs.
Primula Flowers Generally Inexpensive
Most primula plants are comparatively inexpensive. Even large divisions are pretty reasonably priced.
However, the most affordable method is to raise your plants from seed. If the growing season in your area is long, or if a greenhouse is available, polyanthus and garden auricula primroses will bloom the following year from seed sown in early spring.
Primula seed is known to be very slow germinating, sometimes taking several years, unless the seed is sown immediately after harvest.
I usually sow seeds at least six months old since I prefer to start them indoors in late winter and transplant the seedlings to the garden in mid-September.
I have germinated most acaulis, auricula, and polyanthus seeds in less than two weeks by treating them as a Pacific Coast specialist recommended.
The seeds are mixed with a few drops of water in a small vial and then placed in the refrigerator’s freezer for ten days. Twice during this period, the seeds should be thawed out and refrozen.
Then the seeds are freed of excess water by placing them on a towel or blotting paper. They are then sown thinly on the soil’s surface in flats or pots.
On two successive days, they are sprinkled with hot water (120°degrees Fahrenheit) and then with lukewarm water as necessary until they germinate. Recently, I have grown a 2-year-old seed in less than three weeks by this method. Seed may be sown on vermiculite or bagged seedling mix.
Unless there are signs of mold, a plate of glass should be placed over the pot or flat until most of the seed has germinated. The seeds are not covered with soil, but sterile sand should be sprinkled lightly among the seedlings after they grow.
After several true leaves have developed, the seedlings may be shifted to roomier quarters or transplanted to permanent positions 4″ to 6″ inches apart.
In northern Indiana, the primulas’ bloom season is from mid-March until early June, depending upon the weather and the variety. The acaulis strains are the earliest.
One of my sky-blue acaulis, growing in a sheltered position, is often in bloom with the snowdrops, and some of my largest polyanthas bloom with the iris.
Propagation And Winter Protection
The acaulis and polyanthas should be divided at least every year by separating the clumps into individual crowns. It is often recommended that this be done immediately after blooming.
Still, this practice may result in a considerable loss in regions where the summers are hot and dry unless the divisions are kept well watered.
Division in early fall is much safer if the plants can be protected during the winter by being covered with evergreen branches. Division in early spring is perhaps the safest, but it may postpone blooming.
Winter protection is necessary primarily to prevent heaving from the ground and rapid temperature changes. Spruce, fir, or hemlock branches are particularly good as a protective cover; a heavy covering of straw or leaves will favor rot. Where there is considerable snow, no mulch is necessary.
General Culture For Primulas
The general culture requirements of these primulas are simple. They enjoy a relatively rich soil but will tolerate the competition of roots of many deciduous trees and shrubs.
My most successful plantings have been in the shade of fruit trees or shrubs. The soil should have a high humus content and be well-drained.
Since my garden soil drains very quickly and is sandy, I incorporate compost or well-soaked peat moss, which adds humus and increases the soil’s water-holding capacity.
A heavy soil could be lightened with peat moss. Inorganic fertilizers should be avoided, but a fish meal or manure is excellent.
During the spring and summer, abundant moisture will produce the best growth, but when planted in suitable soil in the shade, the species mentioned require no more water than zinnias.
Disease And Insects
Diseases and insects are usually not serious problems. Red spider, which occasionally shows up during dry periods, can be easily controlled by any of the newer miticides.
Crown rot will usually not occur if the soil is porous and the plants are not covered with heavy mulches.
Slugs can be controlled with bait. After you have started with the most adaptable members of the primula group, you may want to experiment with the tall, later-flowering candelabra primroses and others that have more exacting requirements.
But for most gardeners living in dry, warm regions, the rainbow colors of the polyanthus and the true primrose will continue to be the mainstay.
4531 by J Jump