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Penstemon ‘Sour Grapes’


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Great for wildlife
Attracts Wildlife
60cm x 45cm
Partial Shade, Sun
Fully Hardy

Penstemon are short-lived Summer flowering perennials grown for their long-flowering season and popularity with the bees. Also known as Beardtongue, their tubular flowers look similar to those of a Foxglove. ‘Sour Grapes’ is one of the best known Penstemon varieties. Clusters of nectar rich, greyish-blue flowers with a pink blush appear on sturdy stems. Great in borders, rock gardens, along walkways or in containers. We particularly like their cut flower arrangements!

Additional information

Plant Type
Flower Colour
Fully Grown Size
Garden Position
Light Level
RHS Plants For Pollinators
RHS Garden Merit Award
Pot Size
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Penstemon 'Sour Grapes' emerges as a true horticultural delight, earning its place in our selection with delicately interesting blooms and it's ecological significance. Adorned with tubular, bell-shaped flowers in mesmerising lavender and violet hues, this perennial creates a stunning visual display that extends its charm to cut flower arrangements. The elongated spikes of 'Sour Grapes' make an excellent addition to bouquets, bringing the garden's beauty indoors. Honoured with the RHS Plants for Pollinators award, this popular Penstemon variety goes beyond aesthetics, making a positive impact on the local ecosystem by attracting and nourishing pollinators such as bees and butterflies. Its ecological significance aligns seamlessly with our commitment to sustainable gardening practices. 'Sour Grapes' fits effortlessly into various garden styles, enhancing the beauty of cottage gardens, wildlife-friendly landscapes, and contemporary designs. Its versatility extends to different soil types, providing gardeners with an accessible and rewarding plant choice. Our team adore Penstemon 'Sour Grapes'; a pollinator-friendly perennial that not only enriches your garden visually but also offers the versatility to grace diverse garden styles and bring its charm indoors.  

Planting Conditions

For optimal growth of Penstemon 'Sour Grapes,' choose a planting site that offers full sun or partial shade. These perennials thrive in well-drained soils, appreciating moisture without enduring waterlogged conditions. Ensure the soil is not excessively wet, especially avoiding heavy clay soils. Enhance soil drainage by incorporating grit and additional organic matter if required. This thoughtful approach to planting conditions provides a conducive environment for the Penstemon to flourish, promoting healthy root development and contributing to a prolific display of vibrant blooms in your garden.

Watering & Feeding

Efficient watering and feeding contribute to the flourishing growth of Penstemon 'Sour Grapes.' During the Summer, water weekly, adjusting frequency in cooler periods and reducing once the plant is established. Apply a layer of well-rotted manure or leaf mould for annual mulching, promoting moisture retention and soil enrichment. Boost its vitality with a weekly Summer feeding regimen, employing a liquid fertiliser. This attentive approach ensures your Penstemon receives the essential nutrients and hydration for robust development, ultimately enhancing its resilience and vibrant floral showcase in your garden.

General Care

Penstemon 'Sour Grapes' demands prudent general care to maximise its longevity. These short-lived perennials may face Winter challenges, so delay pruning until Spring to safeguard against losses. Secure their continuity by taking Summer cuttings, a proactive measure to prevent potential Winter setbacks. By adhering to this strategic approach to general care and pruning, you can nurture a robust and enduring display of 'Sour Grapes,' ensuring a resilient and vibrant presence in your garden.