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Approximately 2730.00 seeds per gram
seed-counts are only a guide, not to be used for accurate calculations.
B and T World Seeds' reference number:
The average, annual, minimum temperature zone where Penstemon cardwellii is cold hardy
USDA Zone:8 10° to 20°F (-12° to -6.5°C)
Flower or inflorescence:
br. PURPLE, tubular, - 5cm., in infl.
|Height, in meters: 0.3
Height, in feet: 0.99
|Penstemon cardwellii seeds may be subject to seasonal availability
Common names for Penstemon cardwellii:
is included in the following
B and T World Seeds flowering plant categories.
|1||: Stock list|
|Our stock changes almost every day, with seeds arriving and being shipped all over the world.|
We only stock long lived seeds, except for a few species that are always in demand.
Seeds that are not in stock are acquired fresh when ordered.
|9||: Alpine and Rock Garden Seed List (Hardy and Tender)|
|43||: Herbaceous Border Plant Seed List|
|88||: Natives of U.S.North West|
|185||: Plant Species whose germination is improved by Smoke|
|"Smoke" contains a butenolide compound produced by certain plants when heated, it speeds up or starts the germination of seeds from many different genera.|
|700||: Humming Bird Nectar Plants|
Some knowledge about growing from seed is necessary to germinate even the easiest seeds.
Most seeds require humidity to germinate, even desert plants like
require that their growing medium remains moist until germination.|
Most seeds require oxygen to germinate, if buried too deep in their growing medium, or if the medium is too wet,
the seeds may not get the oxygen they require.
Penstemon cardwellii seeds will usually germinate in 18-21 days.
Penstemon cardwellii seeds need to be "overwintered" before they will germinate.
Stratification; cold treatment or vernalization. Seeds of some species 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".