Xela's Garden
Penstamon 'Sour Grapes' [V]
Species: Penstamon.
Penstemon Common Name: Penstemon
Genus: Penstemon
Skill Level: Experienced
Exposure: Full sun, Partial shade
Hardiness: Hardy
Soil type: Well-drained/light, Moist
Height: 75cm
Spread: 60cm
Time to take cuttings: July to August
Flowering period:
July to October
Penstemons are superb value. They are perennials with the flower power of bedding plants, but they can be left permanently in the ground, at least in areas without severe winter weather. Elsewhere, take cuttings in late summer, treat as for pelargoniums and overwinter in a frost-free greenhouse or a window-sill indoors. A large range of named varieties such as rosy scarlet 'Schoenholzeri' is available, and these make handsome, bushy plants producing lots of trumpet-shaped flowers in short spikes throughout summer and early autumn. These blooms help to attract beneficial insects to the garden. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).
Photos of this plant
Reminders for this plant
Due over 15 years ago:
Prune
Penstemons can become woody and leggy if they are not pruned annually. So, to keep plants neat and compact, give them a trim once the hard, winter weather is over (usually in late April or early May). This timing ensures that the old stems are still there to shelter the new shoots from any damaging late frosts.
Step 1 Examine plants individually to see whether the new shoots come from the base or are just appearing along the stems.
Step 2 Cut out all the old stems close to the base
Step 3 Where shoots are growing from the bottom, cut out all the old stems close to the base. Penstemon with few or no shoots growing from ground level should only have their stems shortened, making the cuts just above the lowest set of healthy leaves.
Once a plant has been pruned, remove weeds and other encroaching plants. Apply a general fertiliser, such as Growmore, to the soil to encourage strong growth
Dead head
Remove the faded blooms regularly to prolong flowering.
Take cuttings
Take cuttings from non-flowering stem tips in late summer and over winter for planting out the following year.
Due over 14 years ago:
Prune, weed & feed
Penstemons can become woody and leggy if they are not pruned annually. So, to keep plants neat and compact, give them a trim once the hard, winter weather is over (usually in late April or early May). This timing ensures that the old stems are still there to shelter the new shoots from any damaging late frosts.
Step 1 Examine plants individually to see whether the new shoots come from the base or are just appearing along the stems.
Step 2 Cut out all the old stems close to the base
Step 3 Where shoots are growing from the bottom, cut out all the old stems close to the base. Penstemon with few or no shoots growing from ground level should only have their stems shortened, making the cuts just above the lowest set of healthy leaves.
Once a plant has been pruned, remove weeds and other encroaching plants. Apply a general fertiliser, such as Growmore, to the soil to encourage strong growth
Due over 13 years ago:
Fertilise
Once a plant has been pruned, remove weeds and other encroaching plants. Apply a general fertiliser, such as Growmore, to the soil to encourage strong growth
Prune
Penstemons can become woody and leggy if they are not pruned annually. So, to keep plants neat and compact, give them a trim once the hard, winter weather is over (usually in late April or early May). This timing ensures that the old stems are still there to shelter the new shoots from any damaging late frosts.
Step 1 Examine plants individually to see whether the new shoots come from the base or are just appearing along the stems.
Step 2 Cut out all the old stems close to the base
Step 3 Where shoots are growing from the bottom, cut out all the old stems close to the base. Penstemon with few or no shoots growing from ground level should only have their stems shortened, making the cuts just above the lowest set of healthy leaves.
Once a plant has been pruned, remove weeds and other encroaching plants. Apply a general fertiliser, such as Growmore, to the soil to encourage strong growth
Deadhead
Remove the faded blooms regularly to prolong flowering.
Take cuttings
Take cuttings from non-flowering stem tips in late summer and over winter for planting out the following year.
Due over 11 years ago:
Prune
trim in late April or early May. see previous notes
Fertilise
Apply a general fertiliser (eg.Growmore) to encourage strong growth .... see previous notes
Take cuttings
Take cuttings from non-flowering stem tips in late summer and over winter for planting out the following year
Deadhead
Remove the faded blooms regularly to prolong flowering.
Due about 11 years ago:
Tidy & mulch
See notes for Penstamon 'Garnet'
