Most foxgloves are biennial plants, meaning that they flower at Age 2. The dwarf pink variety ‘Foxy’ falls into this category. After that, the plant dies. So if you have ‘Foxy’ you can leave the seed stalk and hope that it will spread some seed around your garden for another year. In 2016, this biennial will make a small rosette of leaves and put down roots. In 2017, it will put up a flowering stalk. So there is not immediate gratification!
Other foxglove varieties are also considered biennials, but I’ve found I can trick them into thinking they are perennials if I cut down the flowering stalk immediately after bloom. This sends energy back into the root system and keeps the plant reasonably well rooted to bloom another year. If I left the seed stalk, all the plant’s energy would go to making seeds and not roots. The plant might not pull through another winter for me.
This plant also likes to go through winter with its green basal leaves intact and seems to gain energy that way. So don’t cut them away during fall cleanup.
It may be a good strategy to plant a few new foxgloves every year if they are an important part of your garden!