Seed Sowing 101

By Penn Parmenter:

Seeds sown & covered with plastic.

Seed starting for the 2017 season is now underway!

If you’ve never started your own seedlings, this is the time to do it. It’s fun, inexpensive, and the germination process is a kick in the pants.

Besides seeds, you will need a soilless seed starting mix, a flat, 6-pack cells or other small pots. I reuse many of mine year after year and clean them only when I suspect bugs or disease occurred when I used them last.

You can find organic soilless seed starting mixes all ready to go or you can purchase coir and perlite and make your own. Coir is coconut fiber and is great at holding moisture. Although it can be used alone, I mix it with perlite to stretch it. Be sure to buy plain horticultural perlite and not from a name brand like Miracle-Gro as all their products are laced with chemical fertilizer intended to hook your plant. The plain coir comes in an inexpensive small brick; you add water and it expands like crazy. I wet mine with diluted liquid kelp to give the seeds a little nutrition. You can save it and reuse it as well.

Emerging eedlings with cotyledons (first baby leaves).

If I am using my preferred homemade, deep wooden flats, I use filler in the bottom half. You can use leaf mold or, like me, decomposed pine needles from under Piñon trees. I add the coir or coir and perlite on top; the roots love to reach down into the pine needles. I do this to stretch my medium because I grow so many plants, but you can also just use the mix.

An organic store-bought mix is ready to go into flats or pots. Before you start, moisten the mix until it holds its shape just a little when you squeeze it, but not so much that you can squeeze water out. I never use peat pots or plugs; they take a very long time to decompose in our western soils and climate, which makes it harder for roots to spread.

Potted-up seedlings with true leaves. 

Anytime you sow, seed to soil contact is very important for good germination. Sow seeds an equal depth to their size. For instance, barely cover fine lettuce seed but sow larger pea seeds deeper. After you cover the seed with the appropriate amount of medium, press it down with your hand - not too hard, just firm it so the soil and seed come together for the best germination.

Many seed starting kits come with a plastic bottom flat and a clear dome cover to help keep seeds evenly moist through germination. I use a wooden flat with a produce bag on top, which works great. After watering, I lay the plastic on top of the pots, 6-packs or flats to help keep them moist. I spot water around the edges when it dries out. I use little plastic watering tips that screw onto a plastic bottle or a mister for soft, gentle watering. Plastic cake boxes or salad mix containers make a perfect seed starting kit; just add 6-packs or pots. They have a bottom to catch the water and a perfectly fitting plastic dome cover. I used those for years until I graduated to my beloved, old-fashioned wooden flats. Once seedlings are up, I remove the plastic. If damping off disease occurs, (sudden plant death at the soil level), remove the cover and take it off the warmth (heat mat). I find airing out the flat will usually stop it. Misting with chamomile tea (naturally high in sulfur) is a good preventative measure.

Once your seedlings have their ‘true leaves’ it’s time to transplant them; this is called ‘potting up’. After the cotyledons (the first two baby leaves) germinate, the true leaves will be next; they look like the plant you are growing – the cotyledons do not. You can tell that it’s time to pot up when the leaves on top are wider than the pot they are in.

Depending on timing and the variety, you may have to pot up more than once. If you start seeds too early, the plants won’t like languishing in a tiny pot. If they outgrow it, pot them up to the next size (but not too big) while you wait for spring to keep their momentum going strong.

The seed packet will tell you when to plant for setting out in spring. If it says, “sow 4-6 weeks before the last frost” that means before the average last frost date where you live. At 5,000' on the Front Range that could be right after Mother’s Day, but for the mountains it’s usually June 1st or later.

I use recycled 2.5" pots I get from nurseries, but yogurt cups, the bottom half of a milk carton or box container will grow seedlings just fine. Poke a hole in the bottoms though; drainage is important at every stage.

When transplanting, get your station prepared; moisten your potting soil, spread out your materials so everything is ready when you begin to ‘prick out’, the process of lifting the tiny seedling out and into a waiting pot. I use a popsicle stick or butter knife to get under and lift out young seedlings and I always hold them by their leaves, never the stem. It’s too easy to squeeze too hard and kill them. I like to use organic Happy Frog for potting up; its good nutrition means I rarely have to fertilize at all. If I do fertilize, it’s with Liquid Kelp or my own Compost Tea.

I group warm weather varieties separately from cold weather varieties because their germination temperatures vary. This info is often on the seed packet too. Generally, warm weather plants like 75°F to germinate, while cool weather plants prefer 55°F. I use the top of my propane heater or the stovetop for germinating – the pilot light is just right. A cool corner of my house is perfect for germinating cool-loving plants like broccoli, kale and greens. You can also purchase seedling heat mats that regulate the temperature of the flat really well.

If you grow too many plants (and you will), this gives you an opportunity to delight a friend or neighbor with the gift of your own selected, carefully grown variety.

Penn & Cord Parmenter garden and grow food and seed near Westcliffe, CO. Both are regional high-altitude gardening instructors and the founders of Smart Greenhouses LLC, a sustainable greenhouse design company, and Miss Penn’s Mountain Seeds. www.pennandcordsgarden.com