I really love it too. I think it wants damper soil than I can give, but I do my best. It likes marshes.
Mine is in full sun, on the edge of the pavement... in exceedingly well drained soil! Agree that it is very late to emerge . No mention of that in gardeners World site...see link below
Quote...Commonly known as Wallich milk parsley, Selinum wallichianum is a native of the Himalayas where it grows on the open, sunny slopes found there.
In the UK it makes a fabulous border perennial bearing broad umbels of white flowers, held above delicate, fern-like foliage, from July and into autumn. As the flowers fade, they transform into beautiful seedheads that further extend the interest. A reliable and long-lived hardy perennial.
For best results, grow Selinum wallichianum in full sun or partial shade in moist, well-drained soil. Don’t be alarmed if the new foliage takes a while to emerge in spring it usually appears in late spring. Selinum wallichianum has been awarded the Royal Horticultural Society’s Award of Garden Merit (AGM)."
I really love it too. I think it wants damper soil than I can give, but I do my best. It likes marshes.
"Selinum wallichianum is a native of the Himalayas where it grows on the open, sunny slopes found there."
Lol. Ok. Certainly a rocky mountain side sounds very dry. Some sites describe it as a marsh plant. The Times says
"Waterlogged or boggy ground provides the perfect conditions" for it.
Lots of sites say it likes "moist, well drained soil". I always bang on about how this is contradiction in nature. You cannot have "moist, well drained soil". (Other people loudly disagree ).
The Telegraph says this (I have no idea why I should be able to see behind Telegraph paywalls, but I can):
"In our gardens it relishes good deep soil... It thrives here in heavy
clay but does best where the drainage is sharpest. It appreciates a
humus-rich mulch of home-made compost."
That seems contradictory to me. It wants sharp drainage, clay and humus-rich soils. How is that advice of any use at all?
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I'm not sure this is the place for the (useful) exploration, but the swallowtail butterfly exclusively feeds on milk parsley.
"
For a long time [this butterfly] has been confined to parts of East Anglia where its
only food plant, milk parsley, flourishes. The butterfly’s favourite
habitat is wetland, such as the moist bog and fen found in eastern
England.... the swallowtail and the milk
parsley thrived for thousands of years in the wetlands of eastern
England, but from the 18th century onwards this important habitat has
been slowly but surely drained and replaced by wheat fields. The
moisture-loving milk parsley has died out in many areas and the
swallowtail, relying exclusively on this plant, has disappeared along
with it... As a result of research carried out
during these attempts, it has been discovered that it is essential that
the ground is kept very moist to keep both milk parsley and butterfly
alive."
Posts
Agree that it is very late to emerge .
No mention of that in gardeners World site...see link below
https://www.gardenersworld.com/plants/selinum-wallichianum/
Quote...Commonly known as Wallich milk parsley, Selinum wallichianum is a native of the Himalayas where it grows on the open, sunny slopes found there.
In the UK it makes a fabulous border perennial bearing broad umbels of white flowers, held above delicate, fern-like foliage, from July and into autumn. As the flowers fade, they transform into beautiful seedheads that further extend the interest. A reliable and long-lived hardy perennial.
For best results, grow Selinum wallichianum in full sun or partial shade in moist, well-drained soil. Don’t be alarmed if the new foliage takes a while to emerge in spring it usually appears in late spring. Selinum wallichianum has been awarded the Royal Horticultural Society’s Award of Garden Merit (AGM)."
https://www.theguardian.com/environment/2022/jun/22/britains-largest-butterfly-at-risk-as-fungal-pathogens-kill-food-source