Primula Species, Asiatic Primrose, Cherry Blossom Primrose, Japanese Primrose, Siebold's Primrose

A beautiful, tough, trouble-free plant that's well adapted to eastern North America---here it's the easiest of all primroses to grow. ...Read More />
Beautiful showy flowers in late spring, later than most primroses, held above the attractive foliage in umbels bearing 6-11 flowers.

If you want a common name for it, Siebold's primrose is unambiguous. There are many different species of Asiatic and cortusoides primroses.

The flowers show a great deal of genetic variability in color, patterning, size and form, and hundreds of distinctly different cultivars have been named. Colors range from white through soft pink to magenta or bluish lavender, and may differ on the petal reverse. Petals may be smoothly rounded, or as intricately cut as snowflakes. The Japanese have named and registered over 1,700 cultivars, and grow them in pots for their own festival. Check Google images for a taste of the diversity.

The Japanese compare the flower display to fallen cherry blossoms, and call this primrose "cherry-blossom herb". Here it blooms several weeks after the last cherry blossom has fallen.

Unlike most primroses, it can go summer dormant to escape conditions that are too hot or dry for it. Without regular irrigation, it generally goes dormant in mid-summer here (Boston Z6a). Mark the spot while it's in leaf to keep from disturbing it when it's dormant. I find it does best here in dappled shade and woodland conditions, though in Japan it's a plant of moist meadows.

Plants grow vigorously (but not aggressively) from shallow branching rhizomes, soon forming good clumps. Easy to propagate by division any time the ground is workable.

A great perennial for deciduous shade. Like all primroses, it dislikes hot humid summers---but if I lived in the southeastern US and wanted to try growing a primrose, this is the first one I'd try.

This a beautiful spring flowering perennial. It does go dormant in the summer, but until then the color of the flowers and the light gre...Read Moreen foliage simply glow in my shade garden. I can't even describe the flower color - but I love it. The very small initial plant has now become a small colony, and I hope it continues to increase. Very hardy and trouble-free.

December 5, 2007 -

There's a winter sowing database now in the works, so this comment may be totally unnecessary. But fo...Read Morer now, let me follow up on how my efforts to germinate seed of this plant went last winter: I sowed the seed on top of a layer of sand over plain ol' potting soil in a qt-size recycled yogurt container and put it outdoors on February 18, 2007. The seeds began germinating on April 1, and I now have some beautiful plants that look like they'll flower next spring. That's all there was to it - all of the detail below wasn't necessary in light of the fact that for centuries people have been putting pans surface-sown with primrose seed outdoors over winter and winding up with plants in spring.

The seeds seemed to be kept from washing out by lodging among the grains of sand, and I made little roofs of chicken wire to keep out animals. To keep out slugs, I attached sandpaper to the legs of the supporting table with rubber bands.

But I'll leave the details below for the time being to

1) highlight how very much simpler this method was than those below - no monitoring of temperatures, etc. - just put outdoors and forget; and

2) because, between them all, the sources below taught me how varied the germination process can be, and with so many plants' germination inhibitors to "crack", they are invaluable sources to know about.

January 25, 2007 -

Following is some detailed information on germinating this seed. For such a delicately beautiful woodlander that is so particular about the conditions under which it will germinate, I hope others will find this as useful as I do:

1) Sow @ 18-22*C [~64-71*F] for 2-4 wks; then move to -4 to 4*C [24-39*F] for 4-6 wks; then move to 5-12*C [41-53*F] for germination.

2) One site also advises alternately exposing the seed - repeatedly - to 70*F and 40*F for 3 months each. It notes the following:

a) 'Dry storage for 6 months is fatal to this seed"
b) "Germination is very prolonged"
c) "Requires darkness"
d) "Germination is improved by using GA3" (Gibberellic Acid

3) 2nd edition of Norman C. Deno's book, Seed Germination Theory and Practice - Deno's comparative results make an interesting comment on the foregoing:

a) When seed was sown in dark with GA-3, 54% of the seed germinated in the 3rd week, which was less than that obtained without using GA-3 when the seed was exposed to a temperature sequence of 70*F - 40*F - 70*F at 3 months each (62% germinated).

b) Exposing seed to 3 months each at 40*F-70*F-40*F resulted in no germination.

c) Seeds dry-stored for 6 months at 70*F or 40*F were dead.

Hmmm. Since the seed I just received from NARGS was probably harvested no later than last July, germination is looking dubious. Also, wintersowing it now would begin the sequence of temperatures around 40*F, which #3b shows isn't very promising, either. So, I will sow the seed anyway - half by wintersowing method, and the other half by the method in 3a without GA-3 (if I had GA-3, I'd try it).

My best option, at this point, might be to purchase a plant in the spring so I can harvest fresh seed to work with in the future. For the record, let me say that NARGS allows for members to contact the donors of seed like this to see if any fresh seed can be obtained.

This Japanese-Siberian species of primrose makes a good addition to the woodland garden. They have light green, crinkled leaves. A 6-8"...Read More stem arises with a few large white , pink or reddish flowers, often with a white 'star' in the centre. Very attractive species that is available in a number of named selections. The plant will go dormant my mid-late summer so carefully mark the area so you will know where it was planted.