Wednesday, March 12, 2014

Primula Odyssey

When I moved to Michigan on a day much like today (snow in March), I had left behind a California garden full of succulents and tropical plants like fuchsia and hibiscus.  Now it was time to regroup.  I studied the English cottage garden (always an ideal) and prepared to grow herbaceous borders.

Browsing through the seed packets at the garden store, I found Primula veris.  I had read about primroses in English gardens so decided to try it, though it looked difficult.  Two years later, I was enchanted.  The plants grew vigorously, self-seeded, and helped to make spring cheerful and light.  That was the beginning of an odyssey into understanding and growing this genus.

A classic polyanthus. I call this one "Old Yellow".
The most familiar Primula are the polyanthus "primroses".  These are hybrids and many selected varieties exist.  The flowers are held on a stalk, usually above the leaves.  Actually, these are not true primroses.  Botanically minded gardeners sometime refer to them as Primula X polyanthus to indicate that they are hybrids.

Primula vulgaris "True Blue"
The true primroses are Primula vulgaris, a European species that is well known as an English wildflower (but apparently much less common in the wild now).  The flowers are not mounted on a stalk, but arise singly from the crown of the plant, thus are sometimes referred to as "acaulis",  "caul" referring to a stem.  The classic P. vulgaris is a lovely creamy yellow (the color sometimes called "primrose").  But there are many color variants that have either occurred naturally or through hybridizing with garden plants.

But the genus Primula is not limited to our familiar garden plants.  Primulas exist in the wild all over the world, though the single species in South America is likely a modern introduction.  I can make this statement because I possess the most authoritative book on Primula in existence and it describes the range and distribution of the genus. The book is Primula, by John Richards (Timber Press).  Anyone who has become as obsessive as I have about primulas should have the book, which describes the history, distribution, and biology of the genus, as well as its taxonomy.  There are also a selection of color plates.  But for a really wide selection of pictures of primulas, see Pam Eveleigh's gallery of Primula species  (she uses Richards' taxonomic scheme).  As Richards makes clear, the overwhelming majority of primulas are from Asia, or as he puts it, "the eastern Sinohimalaya".

Candelabra primulas
Fortunately, the English, being great plant explorers, brought many Asiatic species home and they are available to gardeners.  The candelabra primroses are descended from those early collections.  They have been hybridized and released as special varieties, which are usually grown in sweeps together. But the species are still grown. The plant blooming to the left is Primula burmanica. Primula helodoxa is just visible to the right.  The hosta behind them is full-size; P. helodoxa is very tall.  The Asiatic primulas appear to require continual seed-harvesting and replanting.  For that reason, there are not many left in my garden.

Primula auricula
Another species that has been widely adapted to gardens is Primula auricula.  There are some varieties that are spectacularly colored, so that they almost appear to be from outer space.  They are usually grown in greenhouses and brought out only for flower shows.  But there are garden auriculas too. Note that the foliage is quite different from the other primulas shown.

Primula juliae
Primula juliae is not only a long-lasting and enjoyable garden subject, but was also the source of some of the colors now available in polyanthus.  It has a different growth habit, creeping to form a little colony over time.

Having grown, loved and lost a number of primulas, I've come down finally to concentrating on those I know will have some staying power in my garden.  They include my faithful Primula veris, the acaulis P. vulgaris types,  P. juliae, and the endless varieties of polyanthus. But probably I'll always be tempted by another challenge to engage more primulas.

This polyanthus is of the true "primrose" color.

Note: this article follows another one on primulas, Primula Fever, which describes more primulas and their hybrids and has more pictures.

No comments: