July Garden Journal: Penstemons

July can be hot, dry, sunny and by now most of that spring moisture has left the soil surface and plants are having to find water deeper down. If you have planted anything this year then your plants may need a little extra help to get established so don’t forget to water and feed if necessary too. A thorough soaking is always best as the water permeates deeper into the soil encouraging the roots to follow – the deeper you can encourage those roots to go the less watering you will have to do in the long term.

Plant of the month – Penstemon
Penstemons are a great old garden favourite, providing long lasting flowers that suit a traditional planting scheme but also look great within a contemporary planting palette too. They can be delicate, they can be big, blousy,  be brightly coloured, but they can be subtle too. There are so many cultivars to choose from that it’s hard to decide as to which one to plant.

The flowers are rather like those of the foxglove and are carried in tapering spires atop 2ft stems. They are produced right through the summer, from June until the frosts, and if you keep snipping off the stems as they fade, even more will emerge – they really do provide non-stop pleasure.

Penstemons were traditionally used as bedding plants in Victorian times as many of the cultivars would not survive the winter. Because of this they fell out of favour and it was wasn’t until the recent resurgence in perennial planting that they became more popular and readily available again. 

They have often been considered a difficult plant to grow as they can be a little unreliable, fade and not return after the winter. However, if you avoid planting them where its damp, maybe adding some grit when planting and never cut your penstemon down in the autumn – (Leave all the growth intact and wait until late April or early May to  trim back to new fresh growth) -   you should be able to grow some of the more hardy cultivars. Be aware when sourcing your plants Its normally the fatter leaved penstemon with the blousiest flowers that are the most tender and need more protection through the winter.

Penstemons thrive in sunny positions and tolerate dry conditions once established, they are easy to grow from cuttings so it can be easy to replace any plants that don’t survive too.  Their pretty colours and elegant habit allow penstemons to blend seamlessly into the herbaceous border. However, be mindful that it is probably best to plant penstemon in the spring rather than the autumn if at all possible.

Penstemon can be used planted with old-fashioned roses, between daisies (asters, rudbeckias and echinacea) and weaved  through softly flowing grasses such as Stipa tenuissima too. My favourite penstemons would have to be Garnet, Hewells Pink, White Bedder and Plum Jerkham. They are all versatile plants and a little tougher than some of the other culitvars. Don’t be afraid of Penstemon, embrace them and you will be rewarded with flowers to complement any scheme all summer long. 

Jobs to be Done July:
Ornamental Garden:
• Continue to deadhead herbaceous perennials and roses as flowers go over.
• Weed!!!
• Continue to edge borders.
• Cutback oriental poppies once flowered.
• Divide bearded irises if flowering is declining – re plant the youngest rhizomes.
• Deadhead roses.
• Trim evergreen hedges.
• Turn compost heaps.
• Cut back spent flowers of climbing hydrangea.
• Feed dahlias / cannas etc.
• Take cuttings of clematis.
• Sow biennials.

Vegetable Garden:
• Thin dessert apples and cooking apples.
• Sow spring cabbages and plant out winter cabbages.
• Water courgettes consistently to encourage a good crop.
• Mulch long term crops like brassicas
• Water fruit trees / bushes.