In conclusion, soaking seeds of Penstemon
digitalis cv. Husker Red in 1000 mgL–1
GA3 for 24 h increases the rate and number
of germinating seeds whether seeds are
grown in petri dishes in a dark, warm growth
chamber, or a soilless mix with a clear plastic
dome over the flat in a warm greenhouse.
Soaking seeds in either 500 or 1000 mgL–1
GA3 and then sowing them in a soilless mix
either lightly covered or on the top of the mix
in a flat covered with a plastic dome in the
greenhouse will also increase the number and
rate of germinating seeds