Initially follow steps 1, 2 & 3 of Upon receipt of your plants.
Growing penstemons is incredibly easy, with very little care and attention required, their major requirement is good drainage - they just can’t get enough! place them in a nice sunny spot and thats it, they are really that simple, but, if that is not enough they are incredibly easy to propagate from - which is another reason why we grow them!
Cultivation: They like an open sunny border, with free drainage adding lots of grit and sharp sand when planting will help if your soil is heavy. Good drainage is especially important if you are leaving the plants to over-winter. If growing in containers a multi-purpose potting compost with added grit to aid drainage, ideally mix the two together before potting.
Planting: Grow in groups to give a eye catching display, if you plant about 18” apart you will soon have a substantial clump, but remember do not disturb them - once planted there they have to remain! If you wish to move them we recommend you take cuttings and then plant the rooted cuttings in the new area.
Pruning: Do not cut back the flowering stems in the autumn as they help to protect the crown of the plant and its new shoots from the frost. When new shoots appear at the base, and all danger of heavy frost is passed, then you can cut most Penstemons well back being careful not to damage the new shoots.
Taking Cuttings: The best time to take cuttings is mid to late summer and over winter them for planting out in the late spring. Traditional “soft wood” cuttings (the same practice as done on fuchsias) will reliably produce results and can be easily rooted in pots on the windowsill. Mix 50/50 of potting compost with vermiculite, Hormone rooting powder will increase your chances of success and be sure to cover the pot with a polythene bag, until they have formed roots then remove. Your cuttings should root within 3-4 weeks, gently water the cuttings in but don’t over water during growth, once they have rooted pot on and then gradually harden off (i.e stand outside during the day and bring in overnight for a week or two) then they are ready for planting out in the garden .
Feeding: Is always beneficial to any flowering plant and Penstemons are no different, our plant food is ideal and can be used throughout the flowering season or alternatively use Miracle Grow or Phostrogen.
Remember Penstemons hate root disturbance and thus do not lend themselves to division.