I have lots of Foxgloves growing in our patch of Ninewells wood. Not surprising as this is one of the wildflowers which is always quick to colonise when an area of woodland has been felled. There were a few to be found around the edge of the wood before the Corsican Pines were removed but now they are quite widely dispersed through out the area. The same has happened in other areas of the wood where pines have been removed. In a few years time their numbers will start to decline as the Silver Birch and other deciduous trees start to grow up and the light levels subside again.
Foxglove seeds are programmed to only germinate in light conditions. A single plant can produce over 7,000 seeds so it is not surprising that lots of plants pop up after a wood has been cleared. How long the seeds remain viable is an interesting question. Trawling through the literature I have found numerous estimates, such as ‘remain viable for many years’ that’s not particularly useful. Then I have read ‘for at least five years’ and I have seen reference to ‘several decades’, but nothing very specific. My guess is that some seeds may remain viable for as long as 50 years. I base this on the fact that our Corsican pines were about 55 years old so the wood had been subject to deep shade for a period of 50 years. Also after the pines had been removed and the brash had been scrapped up into piles, the newly exposed soil quickly produced new Foxglove plants and not just around the perimeter but right throughout the area.
However as I am going to maintain a mix of densities and species of trees they will still manage to grow and flower in certain areas.
Foxgloves flower in their second year, this is a good sized specimen photographed in early April. It should produce a really impressive flower spike later in the year. It will probably survive to produce flowers in its third and fourth year but not necessarily and the flower spike will not be so large.
Of course everyone knows that this plant is both poisonous but contains chemicals which when extracted and administered in the right dosage can be very effective in heart failure. A product called Digoxin was approved for heart failure in 1998. Of course you should not be tempted into any form of self administration. It could kill you.
Although it is toxic to us it is the food plant for the Lesser yellow underwing moth and another moth called The foxglove pug (Eupithecia pulchellata). The caterpillar of Lesser Yellow Underwing will eat a variety of other plants but he Foxglove pug is more fussy and it has an interesting survival technique. Once it hatches, it selects a foxglove flower and using sticky silk threads, seals the opening of the tubular flower and then proceeds to eat the reproductive parts, the anthers and stigmas, eventually pupating inside the flower. Flowers which have a resident Foxglove plug will remain on the flower stalk long after others which were not selected have withered and died.
There is another Foxglove that you might come across, it is called Straw Foxglove (Digitalis lutea) and it is a yellow straw colour with much smaller individual flowers bur still growing in a spike like the traditional Foxglove. It is a garden escape but has become established in the wild in some places. My photograph is of a plant growing’wild’ but only just. It was about one meter away from the fence to a garden but still in a remote rural spot.