On bank holiday Monday a neighbour asked me to take a look at a plant in her garden that wasn’t thriving (a seven year old Euphorbia characias… time to take it out!), and while I was there, she pointed out her Thermopsis montana and exclaimed how much she loved it but in the same breath, what an absolute thug it was, even invading her lawn! I had to agree with her, although it is by no means number one on the nuisance list.
I was therefore very happy indeed to be able to introduce her to its close relative and seldom seen T. lanceolata which is not only well behaved and clump forming, but I find that the soft lemon-yellow colour of its lupin-like flowers is also preferable. The foliage is trifoliate and grey green: it’s hardy and easy to grow and is the perfect cottage garden plant. Looks fabulous with anything in the blue/purple range.
So, buyer beware … the invasive one is T. montana and is also known as T. rhombifolia. And the two most important words to remember are ‘clump forming’ but do double check with the seller!