‘Thorn’ is an extremely long-lived & vigorous Penstemon. I planted it in my garden 8 years ago together with other cultivars & ‘Thorn’ shows no signs of slowing down while most of the others weakened & died after a couple of years. It gets to 2-3’ tall & roots on the ground, so it is getting wider than the 2’ I expected. However, it is by no means a weed & is easy to contain. The name ‘Thorn’ is misleading since it does not have thorns – perhaps it is the name of a person, now forgotten. Sometimes it is misnamed ‘Apple Blossom’ (different cultivar) because the coloring of the 2” flowers resemble apple blossoms: creamy with red tips, very pretty & popular with the bumblebees. Cut off the spent flower spikes & it will bloom Spring-Fall. As with all Penstemon cultivars, cut it back in the winter to keep strong new shoots coming. Side-dress with a little compost in Spring & Summer.