Penstemon barbatus 'Cambridge Mixture'

Sow in February/March for flowering the same year or in August for overwintering. Use a good seed compost and just cover the seed with a thin layer of compost or Sow-Lite (vermiculite). Germination takes 14-30 days at 15-18C (60-65F). Don't exclude light, sealing in a polythene bag after sowing is helpful.

When large enough to handle, transplant the seedlings to boxes or 7.5cm (3in) pots, and grow on in cooler conditions. When well grown, gradually acclimatise to outdoor conditions and plant out in late spring after all risk of frost has passed. Plant 30cm (12in) apart in full sun and well-drained soil.

August sown plants should be overwintered in a cold frame/ greenhouse etc for planting out the following spring. The flowers are excellent for cutting and last well in water.

Seeds and garden supplies will normally be delivered within the time period stated against each product as detailed above. Plants, bulbs, corms, tubers, shrubs, trees, potatoes, etc. are delivered at the appropriate time for planting or potting on. Delivery times will be stated on the product page above, or in your order acknowledgement page and email.

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For more information on how we send your plants please visit our Helpful Guide on plant sizes.