Penstemons are pretty much exclusively found in North America, mainly in the western part. Many of the western ones are challenging to grow in the humid and rainy east, but some of the garden strains are easier. Penstemon gloxinioides "Sensation" is a seed mix which produces a wide variety of colorful plants. P. gloxinioides is a Mexican species (and may be synonymous with P hartwegii, there seems to be some confusion in that I see these "border" penstemons under either name) and thus is not as cold hardy as most of its US brethren, but they grow fast from seed and can be grown as annuals if started early. I remember growing these years ago when I was a kid. I don't see them growing in gardens around here, so I had to search to get seed, and as is often the case, Chilterns in the UK was my source. They usually take a beating during winter in NY, often dying but sometimes respouting from the base, but in this extraordinary year, they sailed through the very mild winter with practically no damage. This allowed them to begin blooming in May, and they are still blooming off and on. I'm sure if I were to deadhead them they would make even more flowers but I want to get my own seed to try in the future. Many new buds are forming so I expect another big wave of bloom in a few weeks time in August.
There are named cultivars of this that are propagated from cutting, I did get a couple of these from Forest Farm and am curious to see how they compare to the seed grown plants. Right now neither of the two plants from FF is in bloom, but I anticipate they will do so in about a month or so.