Person reporting: Barbara Lewis
I should add that the description of P. pachyphyllus would be almost identical to that of arenicola. It blooms a little later. Pachyphyllus does not seem particular about placement in the garden; I had extra seedlings this spring so placed two in a very dry spot that got less than half day sun; they bloomed and are doing well now, in August. Pachyphyllus is another desirable garden plant.
Garden Location: near Denver, CO
Soil: sandy loam
After germination and the growth of three permanent leaves, lined the seedlings out (June 2007) in an area set aside for seedlings. Given shade in decreasing amounts for about a month. Arenicola adapted quickly and grew well in this setting.
Arenicola seedlings transplanted into permanent locations in the garden in late March 2008; adapted immediately and put on growth.. Plants sprinkled every day; currently (June 2008) being watered ever 36-48 hours. By 2009 I plan to have decreased watering to every 7-14 days depending on the weather.
Planted in groups of two or three. I think they look best in groups. Sites included: top of a berm, side of a berm and base of a raised planter.
Of the 45 penstemon species in my garden, arenicola was the first to bloom – third week in April. All the plants put on a beautiful show for about three weeks; their blue color was dazzling. Wouldn’t be without this lovely penstemon.
(Starting in October we will feature Penstemon isophyllus)