- Start the seeds indoors from February-May or August-November.
- Alternitvely, sow directly outside from late spring
- Sow the seeds on the surface of moist, seed compost and lightly cover.
- Cold stratification helps break the seed dormancy. Place the sown tray in a refrigerator for 4-6 weeks if germination is slow.
- Then place in a heated propagator between 18-22c.
- For best germination, provide distinct fluctuations in temperature by moving the tray to a cooler location at night (around 10–15c) and returning it to warmth during the day.
- Seeds will usually germinate within 21-35 days.
- Once seedlings are large enough to handle, transplant them into individual pots.
- Grow on in cooler conditions with good light.
- Gradually acclimatise the plants to outdoor conditions before planting out.
- Plant out after the risk of frost has passed into their final flowering position.
- Water as needed until established.
- Cut back the stems after flowering or leave seed heads in the winter for wildlife.





