Penstemon 'Cambridge Mix' Seeds

Penstemon is a Borderline Hardy Perennial (H3/H4). In most parts of the UK, it will survive the winter comfortably, especially if planted in a sheltered spot with good drainage.

The Survival Trick: One of the most important rules for Penstemons in the UK is not to cut them back in autumn. Leave the old stems and foliage on the plant throughout the winter; this acts as a natural "frost blanket" for the crown. Wait until April, when new green shoots appear at the base, before cutting the old growth down to ground level.

Bumblebee Favorite: The tubular flowers are the perfect shape for bees to crawl inside. They are high-value nectar plants because they replenish their nectar supply very quickly throughout the day.

Penstemons are surprisingly easy to raise from seed and grow quickly enough to often flower in their first year.

How to Sow:
Sow indoors from February to April. Surface sow the seeds onto moist, well-drained seed compost. Do not cover the seeds (or use only a very fine dusting of vermiculite) as they require light to trigger germination. Keep at 18-20°C. Germination usually takes 14-21 days.

Where to Plant:
They thrive in full sun or partial shade. The most critical factor for their survival is drainage. They hate sitting in cold, wet soil over winter. If you have heavy clay, add plenty of grit to the planting hole to help the roots stay dry during the British winter.

Ongoing Care:
Deadheading is essential. If you snip off the faded flower spikes, the plant will immediately push up fresh new ones. This cycle ensures a continuous display of jewel-toned bells from midsummer right through to the first hard frosts of November or December.

The vertical, bell-shaped spikes of 'Cambridge Mix' look best when contrasted with softer textures and flat flower heads from our collection:

• ☁️ Achillea 'Ballerina': The Shape Contrast. The fluffy, white button-like flowers of Achillea provide a perfect horizontal contrast to the upright tubular bells of the Penstemon. Both are incredibly long-flowering.
• 🌾 Briza Maxima (Quaking Grass): The Texture Match. The nodding, shimmering seed heads of Quaking Grass add movement and an airy, naturalistic feel to the solid, colourful clumps of Penstemon.

Sow indoors in spring for flowers from June until the late autumn frosts.