Now's the time for starting seeds indoors

Posted by talkdirt

Posted: April 7, 2008 - 3:31 pm

seedlings: Seedlings photo by Fran Durner

Cheryl writes: Spring must be here. Really. People (a few: OK, young) in flip-flops were squealing their way through icy puddles at Lake Otis and Northern Lights last Wednesday, and every one of the 30 chairs was filled at Dimond Greenhouse’s session on “General Spring Gardening,” or “Planting Seeds.”

Not outside yet. Might as well plant in the refrigerator. In Anchorage we’ll average only 90 frost-free days between May and sometime in September. Most plants take longer than that to produce, but we can give them the time they need by starting them indoors. This can save considerable money, and also, you can treat yourself to varieties not generally available at the nurseries. Old-fashioned vining petunias, for instance, or Italian white sunflowers.

Darryl Leiser, son of greenhouse owner Wayne Leiser, was cheerleader Wednesday night for the self-starters. He took out the mystery but left the wonder of getting pansies, petunias, dusty miller and stocks up in the house with help from a bright south window, or with grow lights.

It’s almost all about light. Seedlings need 10-12 hours of light a day (we’re up to more than 13 hours now). Grow lights offer you more control than the sun streaming through the windows but also cost, though except for the power, the expense depends on how much you want to throw at the ensemble.

One “special” grow light with enameled reflectors, timers, adjustable heights, etc., can set you back hundreds of dollars. They are mighty good-looking and work fine. Or you can go to the hardware store and build yourself a fluorescent double-bulb setup -- one cool white (CW) plus one warm white (WW) -- with a manual switch or plug, and raise and lower it with twine or shoelaces. That costs in the neighborhood of $50-$60. It will work fine too.

The time, says Darryl, is now because Memorial Day weekend, the magic planting-out holiday in Southcentral, is on its way.

Every single thing Darryl advised came from 90 years of experience with Leiser family greenhouses. “There are plenty of other ways of doing it,” he said, “ways that work, and if they’re working for you, then keep doing them. But these work for us, so they’re the ones I’m going to talk about.”

First comes good starter soil -- not dirt. The nursery uses a professional growing mix, a soil-less soil compound that’s sterile for starting seeds. Tailored compounds are more expensive but not more effective.

“Labeling is for people, not plants,” said Darryl. “Tomato mix, rose mix, azalea mix – they’ll make you feel better to buy, but the plants don’t care.”

A good growing mix acts like a sponge. Water won’t pool on the top (if it does, the mix is too dense) or sluice through (the seedlings will dehydrate).

Scoop the mix into small containers. He used a black plastic one about the size of a half-gallon milk carton. Lay something like a pencil or bamboo stick in the mix to make rows of uniform depth.

Cut the top off the seed packet, sprinkle in a little Bonide Bulb Dust and shake the packet to coat the seeds. The bulb dust contains sulfur and thyram and prevents damping off, the virus that can take out a flat of seedlings in two days. Damping off can’t be cured once the infection starts, but it can be prevented.

Planting the seeds in rows, rather than broadcasting, also makes it harder for the virus to jump.

Go up and down the rows, gently tapping the packet with a pencil to shake the seeds neatly into their furrows without letting them touch. Then carefully blanket the rows to a depth the size of the seed. An eighth-inch seed gets an eighth-inch of compound over it.

And label each row with the plant’s name, color and planting date. Seedlings look much alike. In six weeks, you won’t notice where the red petunias stop and the purple ones start. The neighbors, however, will. Later.

A garden log, says Darryl, is one of a gardener’s best friends. If your indoor planting was a little late this year, next year you can move it back several days. And you can keep up with what worked, what didn’t, what you’d like to do again and what you wouldn’t do at gunpoint.

Water the container gently, then put a plastic cover over the top of your bedding tray. These can be purchased, but a plastic bag is about as good. This is to prevent evaporation. You don’t want to water. “Watering at this point would be like Niagara Falls falling on these poor little seeds,” says Darryl.

When you see green in the tray, crack the plastic for 24 hours, then remove it. Now you can water. Gently.

Big seeds such as sunflowers, nasturtiums and lavateria are started individually in compartmentalized flats, a couple of seeds for each compartment. “The bigger the seeds, the faster they germinate,” Darryl says.

The middle of April or beginning of May, for instance, is plenty of time for sweet peas.

When the seedlings in the flat are about an inch high and have two sets of leaves, they’re ready for transplanting to individual pots. Gently take them out with something like a dibble stick, always holding them by the leaves, never the roots, and place them in their bigger homes, watering them in well.

“You water when your plants are dry,” he says. “Almost all plants like to dry out. It gives them incentive to develop roots.”

After 10 days or two weeks, the seedlings are ready for their first meal of mild liquid fertilizer. You want them to be stocky, heavy-set, rather than lank and spindly. Pinch them back if you need to to encourage them to branch.

About a week before you set them out, start getting them used to the idea by hardening them off. Used to, that involved taking the indoor flats outside for an hour the first day, two hours the second, three hours the third and so on, but as Darryl says, what working person has the time? No, he says, when the temperature is 42 in the morning, you know it’s just going to get warmer, so set your flats in a shady area when you leave for work, and bring them back inside when you come home.

If you don’t do this and shift them straight from house to flower bed, sun shock will set their growth back six weeks, he said.

Every time the nursery waters anything, it gets a much-diluted dose of fertilizer (here, Miracle-Gro), he says, on the theory that steady sustenance beats binging. Inside, outside, the principle is the same, and this holds true also for organic feeding. A 15-30-15 (nitrogen, phosphorus, potassium) formulation is good for flowers and vegetables, he says.

It’s better for plants to water the soil around them instead of splashing the leaves or flowers, and as to timing, in morning or evening. Whatever the ambient air, our soils are cold, and a splash of cold water at midday can surprise a plant as much as it would you.

The nursery puts Osmocote, a pelleted time-release fertilizer, on the surface of anything bigger than a 6-inch pot. In flowerbeds, they use it at the beginning of the season. Some people report good results. Some say it makes no difference.

That’s one of the wonderful things about gardening: Except for general guidelines, the rules are whatever works for you, so everything you do always has the potential of being a new adventure.

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