Answer: In my experience the foxgloves will self seed where they are happy and the strain will self-select to some extent to accommodate itself to the growing conditions in your garden. The Excelsior and Shirley strains are both dramatic and tall and may need staking; since they are seed strains it will be up to you to select the best plants and allow them to reseed while deadheading the lesser quality plants. Without that effort, there may be some degradation in quality over time. This would be true with any seed strain you use. You might also find that one strain or another is better suited to and simply does better in your garden, so it is worth experimenting a bit.
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