Will Pulsatilla vernalis survive wet, mild winters?

[Gene Mirro]

I can give them well-drained sandy soil.  But the winters here are very wet and mild (typically 5C) and cloudy.  Will they survive outdoors?

[Hoy]

Hi Gene,

Sorry, I have never tried P. vernalis down here at the coast, only at the mountain cabin.
I have had other Pulsatillas though and they do fine as long as they are not crowded out by neighbours.

[Steve Garvie]

Our conditions in eastern lowland Scotland are very similar with no shortage of winter rain, frequent mild episodes and almost complete lack of snow cover. The coldest month is January with a winter average of 3C; December and February being 5C & 4C respectively. These are the conditions in Cyril Lafong's garden where Cyril grows a few P. vernalis outside without cover. A quick google search should reveal images of Cyril's award-winning plants.

If memory serves me right the open garden plants are seed-raised from his own stock over a number of years and so there may have been some selection to favour seedlings better able to cope with local conditions here. Cyril's garden is on a southerly sloping aspect with surrounding tree cover and so is not generally exposed to strong wind.  In mid-winter one of the beds containing P. vernalis is in perpetual shade of the house due to low winter sun.

If you wanted to maximize your chances of success I would select as exposed a site (for wind) as possible, in good light and with good drainage. Avoid tree leaves and wind-blown detritus in the evergreen foliage and consider using a sheet of glass as winter cover (november-->flowering time). Though drainage, wind exposure and good winter light are helpful, scorching summer sun and dryness at the root in growth will likely prove fatal.

Hopefully Cyril will see this thread as he is best qualified to answer ............and has the plants to prove it!   

[Cyril L]

I can give them well-drained sandy soil.  But the winters here are very wet and mild (typically 5C) and cloudy.  Will they survive outdoors?

Hello Gene

I agree with Steve’s advice.  The well-drained sandy soil is certainly a good start for your wet climate.  High summer temperatures may be more detrimental but I think the summers in Washington state are cool, which should be of benefit.  A cover over winter will undoubtedly help and may give a better flowering performance but I do not provide any protection for my plants in the open garden.

In eastern Scotland, temperatures rarely get above 25 C in summer and annual precipitation is 70 cm.

One of my plants grows in a crevice bed with a sandy soil and gets very little sun in winter.  It is 4 years old, grows slowly due to the poor substrate and has 3-4 flowers in the spring.  Another plant on a raised bed is older but bigger and bears up to 8 flowers.  This bed gets a lot of sun but is well drained.

I suggest trying plants in different locations in the garden but the optimum place would be a cool place with plenty of light.  Sometimes it is a matter of trial and error to find out the ideal spot.  Also, some clones may be more suitable for a particular environment.  My plants are seed raised from a plant of the Scandinavian (Norwegian) form I got in 1998 (which is grown in the alpine house).  These plants are more vigorous in cultivation, producing more flowers than those from mainland Europe.

I know of a garden, about 50 miles north of where I live (so cooler) where P. vernalis used to be easy to grow outside, but this is not the case now.  There may well be pathogens that eventually get a hold in a particular environment, making life difficult.

Cyril

[Gene Mirro]

Thanks for the information.  My climate transitions from winter to spring very very gradually.  So this plant will probably be blooming in dark, wet weather.  The flowers may not get pollinated.  Since I would like to collect seeds, I think I will try it in the cold greenhouse.  I may have to hand-pollinate.