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Begin gardening early by starting perennial seeds indoors

“The seed-starter works, always, at the edge of a mystery. Though we may take it for granted, we are part of that mystery, along with the fragility, resilience, the dependability of the green world.”

– Nancy Bubel, The New Seed-Starters Handbook, 1988

As the last leaves fall from the trees in my yard, I have been moving my gardening indoors to my greenhouse, where I’m beginning to sow perennial flower seeds.

I agree with Nancy Bubel about the joys of starting plants from seeds and, to me, there is something particularly satisfying about nurturing seedlings inside during winter while most herbaceous perennials outside are dormant.

First, I gather all of my perennial seed packets and come up with a sowing schedule. My choices for the first seeds to sow include spring-blooming flowers such as columbine and wall rockcress. Although many perennials will focus on developing healthy root systems and foliage the first year and then bloom during year two, others will flower the first year if they are started early enough. I’m trying this with carnation and veronica.

Estimated germination times listed on the seed packets are also important to note. Although most perennials take 2 to 4 weeks to germinate, others, such as white trillium and queen of the prairie can take 3 to 6 months.

Some seeds need special treatment before sowing, such as scarification, soaking or cold stratification. Seeds with a hard outer coating, such as bear's breeches and the climber passion fruit, should be nicked with a sharp knife or razor blade and soaked overnight to assist germination. Other perennials need a period of moist, cold conditions in order to germinate, including anemone and delphinium.

Next, I prepare the planting medium for sowing. I like to use a prepared, sanitized, soil-less medium consisting of finely screened sphagnum peat moss and perlite with an added wetting agent that improves water permeation. Other gardeners I know like to make their own seed-starter mixes, while others use potting soil. I’ve had the best results when using a light, airy mixture.

Seeds should be sown in a pre-moistened medium. I pour it into a wheelbarrow, add water, and mix with gloved hands until the medium is damp but not wet. Then, I fill 3- or 4-inch pots with the medium and tap once or twice against the tabletop so the medium settles evenly, leaving a 3/4-inch space from the rim. I still sometimes sow seeds in multi-celled plastic trays, but have switched to using more small pots because they make it easier to accommodate the needs of individual seedlings, and they allow seedlings more room to grow strong roots, thus reducing transplant handling. As I fill up the pots, I arrange them on a plastic tray that makes carrying multiple pots easier.

Most perennial flower seeds should be lightly pressed into the soil and barely covered with a sprinkling of the medium. Larger seeds will need to be planted about 1/4-inch deep and covered. Light usually aids in germinating herbaceous perennials, although there are some exceptions. Blackberry lily, cyclamen and forget-me-not all require dark conditions to germinate. (Read more about lighting in this week’s blog, http://blogs.esouthernoregon.com/theliterarygardener.)

Finally, I place a plastic dome over the trays and pots to retain heat and protect plants from cold damage. Some perennials germinate more successfully in drier conditions, including hollyhock, coneflower and lupine; for these, I leave the dome off and cover with floating row cover at night if needed. I keep my greenhouse air temperature around 45 degrees at night, and the thermostat for the heating mats, providing bottom heat to the trays, is set at 70 degrees. I prop open the domes during warmer days so the soil doesn’t become too wet, which can foster a fungal disease called damping off.

Greenhouse gardening in the winter is magical. On days when it’s dark and gloomy outside, I love the feeling of being inside, gazing on rows of new plant life awash in other-worldly fluorescence. There, I work enthusiastically, as Nancy Bubel put it, “at the edge of a mystery.”

Rhonda Nowak is a member of the Jackson County Master Gardener Association and teaches writing at Rogue Community College. Email her at rnowak39@gmail.com.