Penstemon 'Cambridge Mix' Seeds
If you want a plant that starts blooming in June and is often still going at Christmas, Penstemon is the answer. 'Cambridge Mix' is a stunning selection producing tubular, foxglove-like flowers in a riot of jewel tones: rich crimsons, deep purples, bright pinks, and cool blues, often with contrasting white throats.
These plants bridge the gap between bedding and shrubbery. They form bushy, semi-evergreen clumps that provide structure and colour for months on end. They are absolutely essential for the "late summer" garden, keeping the show going when the lupins and delphiniums have finished, and they are a top-tier dining station for bees.
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🌿 Understanding the Plant
Penstemon is a Borderline Hardy Perennial (often treated as H4).
It will survive most UK winters, especially in sheltered spots. It keeps its leaves in mild winters (semi-evergreen).
The Survival Trick: Do not cut them back in autumn! Leave the old top growth on the plant over winter—this acts as a frost blanket protecting the crown. Cut the old stems down to the ground only when new green shoots appear at the base in late spring (April).
🌱 Growing Guide: How to Sow and Grow
Penstemons are easy to raise from seed and grow quickly.
Germination:
Sow indoors from February to April. Surface sow onto moist compost and do not cover (or use a very fine dusting of vermiculite), as they need light to germinate. Keep warm (18-20°C). Germination takes 14-21 days.
Where to Sow:
They thrive in sun or partial shade. They prefer free-draining soil. If you have heavy clay, add grit to the planting hole, as they hate sitting in wet soil in winter.
Care While Growing:
Deadheading is key. If you snip off the faded flower spikes, the plant will immediately push up new ones. This cycle keeps the colour coming well into autumn.
📋 Plant Specifications
| Latin Name | Penstemon hybrid |
| Common Name | Penstemon 'Cambridge Mix' |
| Hardiness | H3/H4 (Borderline Hardy - protect in harsh winters) |
| Light Required | Sun / Part Shade ⛅ |
| Height | ↕️ 60cm - 75cm |
| Spread | ↔️ 45cm |
| Spacing | 🌱 40cm apart |
| Great for | 🐝 Bumblebees 📅 Long Season Colour 🏡 Cottage Borders ✂️ Informal Cutting |
| Seed Count | Approx. 100 seeds per packet |
🤝 Perfect Garden Companions
The bell-shaped flowers of Penstemon look best when contrasted with flat heads or soft grasses:
- ☁️ Achillea 'Ballerina': Shape Contrast. The fluffy, white buttons of Achillea contrast beautifully with the long, tubular bells of the Penstemon. Both flower for a long time through summer.
- 🌾 Briza Maxima (Quaking Grass): Texture. The nodding, shaking heads of the grass add movement to the sturdy clumps of Penstemon, creating a relaxed, naturalistic feel.
📅 Sowing & Flowering Calendar
Sow indoors in spring. Flowers from June to November.
| Month | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow Indoors | 🟢 | 🟢 | 🟢 | |||||||||
| Flowers (Yr 1+) | 🌸 | 🌸 | 🌸 | 🌸 | 🌸 | 🌸 |
🏆 Officially Recognised Excellence
Penstemons are a top priority for bumblebees. The tubular flowers are the perfect shape for bees to crawl inside, and they replenish their nectar quickly throughout the day.
- Regular price
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£2.20 - Regular price
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- Sale price
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£2.20
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