B and T World Seeds' reference number:
USDA average, annual, minimum temperature Zone:7
Type of plant - perennial
Flower: deep PURPLE, WHITE throat
Height in meters: 1
Penstemon Stapleford Gem
is included in the following B and T World Seeds flowering plant categories:
43: Herbaceous Border Plant Seed List
185: Plant Species whose germination is improved by Smoke
Penstemon Stapleford Gem seeds will usually germinate in 18-21 days. Normally will only germinate with light so surface sow. Sow seeds about 1mm deep in a Well drained seed sowing mix at about 15°C.
Stratification (cold treatment or vernalization) Some seeds need to be overwintered before they will germinate. Some seeds need just a couple of weeks, others 3 months. Seeds can be stratified in dampened peat or sand, in a plastic box or bag at 4°C or 5°C in a refrigerator. The seeds should not be frozen or in a wet medium. Very small seeds can be sown on the surface of their growing medium, in pots sealed in plastic bags, and kept in the 'fridge. Many vernalized seeds need light to germinate when they are sown in the "Spring".