Primulas

The Genus Primula is one of the largest and most popular genera. Approximately 425 species are known and new ones are still being discovered. In addition thousands of hybrids are grown including all the modern primroses and polyanthus.

The vast majority of species (over 300) are concentrated in the Himalayas and western China. Europe by contrast has only 33 and North America 20.

Species vary from tiny ground hugging plants to large candelabra primulas with 3ft high flower stems. Some grow at or near sea level while many are high mountain plants. Colours cover the whole spectrum.

Primula edgworthii
Primula Edgworthii
Section Petiolares
The number of species in cultivation at any one time is difficult to gauge but is probably between 200 and 250, although this may be on the high side.

Some of the most beautiful, usually mountain primulas, are almost impossible to grow in cultivation or are not long lived. On the other hand there are many easy species that can be grown in the garden.

The genus is classified into 37 sections of which 24 are confined to the Sinohimalay. The 33 European species are classified into four sections and the 20 North American into five.

The majority of Asian species were introduced into Europe by such famous plant hunters as George Forrest, Major George Sherriff, Frank Ludlow and Frank Kingdom Ward. Ludlow and Sherriff , who worked together, introduced 66 new species. Many others, before and after them, collected primulas, as well as other plants, and in the early part of the century it was a highly dangerous occupation. Some of the earliest plant hunters, French Catholic missionaries, were killed and George Forrest, on his first expedition between 1904 - 6 was lucky to escape after being hunted for days by Tibetan lamas.

In general primulas enjoy mild and humid conditions. They do not like being frozen nor do they like temperatures above 20 degrees centigrade. Where primulas grow in cold areas they are usually covered by a blanket of snow in winter.

Primula Modesta
Primula Modesta
Section Aleuritia

Most primulas are moisture lovers and need a constant supply of water and air at the roots during the growing period. Soils should contain plenty of organic matter, many prefering leaf-mould in generous quantities. Well-rotted cow, horse and sheep manure are also beneficial as many species are heavy feeders.

While most primulas are moisture lovers they do not like stagnant conditions and free drainage is essential. A few species, like the candelabras and their hybrids, do prefer more boggy conditions but they are the exception.

Many primulas are suitable for pot culture like Primula Wulfeniana of section Auricula or are grown in pots in cold greenhouses mainly as a protection against excessive moisture. Some are grown this way as they will not survive our generally damp and muggy outdoor climate. Others need special attention to survive. While primulas are generally hardy a few species are less so and are best grown in a heated conservatory.

There are a number of Japanese species and one of these, Primula Sieboldii of Section Cortusoides, is a cult plant with many Japanese flower societies devoted to their cultivation and exhibition. Hundreds of selected clones are grown. There is also an American Sieboldii Society.

Primula wulfeniana
Primula Wulfeniana
Section Auricula


References Primula by John Richards.
The genus Primula In cultivation and the wild by Josef Halda.
The genus Primula, Smith and Fletcher.
See Richards for extensive bibliography.



For photographs of primulas go to   Primula Gallery        

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