When foxglove is mentioned, we think of the biennial Digitalis purpurea, the best-known and most common foxglove. However, that particular foxglove does not do well for us. It is not that you cannot grow it. It does grow, but rather reluctantly. In both gardens I have had, you could grow them, but not very successfully. It must be due to a combination of climate (they can be killed by our winters) and soil (they prefer a slightly acidic soil). However the other foxgloves, mostly yellow, do very well for us.
|Various Digitalis naturalized|
There are two yellow foxgloves, the large yellow foxglove (Digitalis grandiflora) and the small yellow foxglove (Digitalis lutea).
|Digitalises lutea and grandiflora|
Digitalis grandiflora is a yellow, perennial digitalis. You would expect that with a name like grandiflora, the flowers would be rather large. In fact, they are bigger than those of the small yellow foxglove, but not as big as those of Digitalis purpurea. It is really perennial. I have clumps that are very old. It is supposed to be the toughest of foxgloves. Like all foxgloves, the plant grows from a rosette, and the flowers are speckled spots, in this case brown. If you cut the stem after it has flowered, it might bloom again later on.
Digitalis lutea is also perennial. As you can see from the picture, I grow it in a rather wild area where it has naturalized and seems to be able to survive competition. Since it prefers shade, I was thinking I should move clumps of it next to some hosta. The flower scapes would look quite nice blooming above the hosta leaves.
|Digitalis lanata with D. lutea in the background|
I particularly like the Grecian or woolly foxglove, Digitalis lanata. The name refers to the leaves that are woolly. The white flowers, veined in purple/brown, are also a bit woolly. These flowers are bigger than those of Digitalis lutea but smaller than those of grandiflora. In our garden, Digitalis lanata are biennial and select their own spots. They self seed, just a few here and there, in dry sunny spots. All three of these digitalises are about the same size, 60 to 70 cm.
The most interesting thing about the woolly foxglove is that it is used medicinally. All parts of digitalis are poisonous. They slow down the heart. Fortunately they are very bitter, and it is unlikely anyone would eat them. In 1785, a Dr.Withering discovered that it could be used to treat heart failure. It is a particularly interesting story because in fact he did not discover the medicinal properties but learned about them from "an old woman" a Mrs Hutton. So it is an example of an important medication that was actually discovered by traditional healers. Also interesting is the fact that nowadays, unlike most medications, the active ingredient is not chemically synthesized, but extracted from the plant, Digitalis lanata.
|Digitalis lutea and grandiflora|
I have also grown a biennial called Digitalis ferruginea which, as the name implies, is rusty coloured and quite tall with small flowers. I don't seem to have taken any pictures of it. It is more interesting as an architectural plant, since it reaches 1.2 meters.
Another interesting thing about foxgloves is that the name does not come from fox but from folks. In this case the "little folks" or the fairies. As well, apparently, if you make an infusion of foxgloves and put in the water of a flower arrangement, the flowers will last longer!