Growing Silene/Rapid Flowering:

Preparing Racks of Conetainers:

Large numbers of plants are grown in small "conetainers" from Steuwe and Sons.
Spread the soil mix over the top of the rack and into the tubes, allowing the tubes to fill with soil.
Remove the unusually large chunks of pine bark etc.
When the tubes are filled to the top, firmly compress the soil into the tubes with your fingers.
Refill the tubes to the top with fresh soil (don't use the soil that has fallen beneath the rack while filling it; that soil is too fine, and should be thrown out or mixed back in with the rest of the soil mix).
Pick the full rack up off the table and strike it back down against the table two or three times. The top of the soil mix should now be just below the surface of the tube and the tubes should be relatively homogenous.

Seeds that have stored dry for approximately one month before planting have the highest germination percentage.
Before sowing the seed, the tubes filled with soil mix must be thoroughly watered. It is difficult to moisten the soil down the entire length of the tubes. Water them several times, allowing the water to soak in each time. You can tell when a tube is dry at the bottom because it feels ligth at the bottom and heavy at the top when you hold it in your hand.
Drop 1-2 seeds on the surface of each tube.
Germinate the seeds on a mist bench, and allow them to grow up a bit before transferring them to a regular watering scheme.

When most of the seedlings have large cotyledons, or the first true leaves can barely be seen, transfer them to a standard greenhouse bench.
Continue to water them gently, e.g. from a can with the nozzle upturned, so watering does not lay the seedlings flat on the soil.
Thin the plants to one seedling per tube.
Fertilize them with a dilute 20:20:20 fertilizer (e.g. Peters at ~1/2 tsp. per gallon).
With Silene latifolia, do not fertilize them in any regular fashion. Wait until the tips of the leaves are beginning to show a bit of red before you fertilize. A larger percentage of plants flower, and they do do more quickly when the plants are kept at relatively low nutrients. You'll know you've overfertiized when the plants crowd each other and only about half of them flower. At this point, it is faster to plant some more seeds than it is to wait for the rest of your plants to flower. Silene vulgaris seems to flower rapidly, even if you fertilize them quite a bit.
To encourage flowering, use lamps or otherwise ensure they have 16 hour days. In addition, have the lamps turn on from 30 minutes to 1 hour in the middle of the night to interrupt the dark period.

Department of Biology, PO Box 400328 University of Virginia, Charlottesville, VA 22904-4328
Email: drt3b@virginia.edu Phone:(434)982-5217