Start your … seeds |

Start your … seeds

Carol O'Meara
The Denver Post
Special to the Daily

One look at the cheerful, bright portraits of veggies and flowers had you purring with delight, your willpower crumbling before their sun-drenched colors. You pored over catalogs, mapped out your planting plan and ordered the seeds. But now those packets are here and you’re staring at them, wondering if the equipment to get them started will take a bigger investment than your kids’ college tuition.


What you need to grow food from seed is closer than you think: in your kitchen. Food containers, cups, cartons and jugs are perfect for sprouting your own groceries without breaking the bank.

“I’m using those clamshell containers you get buying fruit, like blueberries,” says Steve Newman, greenhouse crops specialist for Colorado State University Extension. “They’re perfect for starting seeds, with holes in the top and bottom for drainage and ventilation. All you do is put a bit of clean seed-starting mix into the container, sow your seeds, then close the lid.”

Newman has a 3,200-square-foot greenhouse equipped with high-tech lights and monitors at his disposal. But he still starts his family’s vegetable garden from seed at home.

“It’s easy and fun. Anyone can do this, and it’s a great project to do with kids. Give them their own little container to put on their windowsill.”

Those baby plants want at least an inch of starting mix and more than an inch of air space, so try to purchase the larger tubs of berries, not the half-pint, 1-inch tall boxes. When you’re done noshing on fruit, run the tubs through the dishwasher on the top rack to clean them.

If you don’t have berry boxes, almost anything can be used to start seeds, even egg cartons. Those made of Styrofoam need drainage holes poked into the bottom of each cell; the pressed paper ones don’t. But the paper ones do start breaking down quickly. Plant them, egg carton and all, right into the ground (Styrofoam should not be planted).

To help seeds germinate, use a humidity tent, a plastic covering that holds moisture in. But not all household plastics are the same, Newman warns; plastics either breathe or don’t breathe. Bread bags are ideal tenting, while shrink wrap is a no-no. Milk jugs with the bottoms cut off make good covers.

OK, now stop scrimping

Recycled containers are fine, this guru of greenhouses says, but when it comes to the black stuff, don’t scrimp. Seed-starting mixes give you what you pay for. Top-quality, soilless, sterile medium helps avoid disease problems.

The biggest danger to seedlings is drying out. Newman recommends placing one sheet of paper toweling at the bottom of the container, then putting the box on a water-holding tray. Water from the tray will be absorbed by the paper towel, then into the seed mix to water the baby roots.

As the seedlings sprout, crack open the container to let air circulate inside. Overly humid conditions will encourage damping off, a stem-killing disease caused by a fungus. Also, immediately place the youngsters under lights so they don’t stretch and become leggy. Seedlings should be stocky; if yours start reaching, Newman suggests sprinkling a small amount of potting soil around the stems to encourage roots to grow.

Tomatoes, peppers, eggplants and herbs can be started this way. Once they get a set of true leaves – not that first pair that pops out of the seed case – pick them out and pot them into a slightly larger container. Two-inch pots work best, since seedlings should slowly graduate up into slightly larger containers. Plop them into huge pots too soon, and they’ll suffer from salt buildup in the soil. Fertilize them at half strength until they’re 4 to 6 inches tall as often as the fertilizer package directs.

Timing is everything

If you want cucumbers, melons, pumpkins and squash to get a head start, use a different method. Their fragile roots are fussy about transplanting.

Newman recommends a simple, transparent technique: Jiffy pellets under plastic. Hydrate some Jiffy Pellets (the small peat discs that plump in water), put them on a plastic tray, and then plant one or two seeds per pellet. Cover each pellet with a clear plastic cup. Once the seeds sprout, pinch off the weaker ones, leaving just one seedling per pellet.

They’ll grow aggressively, so wait until two weeks before planting out to start them so that they go into the ground quickly. (You’ll need to tear off the net casing of the Jiffy Pellet before planting but be gentle about it.)

Tomatoes, peppers and eggplants need six to eight weeks indoors; start them now and plan to repot them as they grow.

Seedlings should get plenty of sunshine, but if you don’t have a sunny southern window to put them in, you’ll need lights.

“This is where things can be simple or complex,” Newman says. Although his own 1,000- watt light setup turns his shed into a glowing sunburst, Newman admits that home gardeners don’t need that much light.

“I start most of my seedlings under a fluorescent shop light with one cool white and one warm white bulb. Or use cool white fluorescents with incandescent bulbs in a nearby lamp. This provides the spectrum of light plants need to thrive,” he said.

You don’t need a huge investment in lights, says Trela Phelps general manager of City Floral, Denver’s oldest greenhouse. As hydroponics have become popular, the cost of grow lights has come down. If space is small, they’re ideal for seed starting. Still, keep lights close to seedlings – 2 or 3 inches above them – so they don’t stretch.

“Seed starting is a big thing now. It’s the most popular class we offer,” says Phelps, a 24-year veteran of the retail garden center. “People are excited about it; they’re starting things that they can’t find at the store, unusual varieties they want to try.”

Corn and beans are the easiest to sprout, she said, making them a good choice for gardening with children. “They’re perfect for little kids who want to try a science experiment,” Phelps says.

But don’t overinvest, Phelps cautions, or seed-starting becomes more expensive than purchasing seedlings at the store. “Seeds aren’t too expensive; you can buy a package for 79 cents. After that, all you need is a tray, peat pots or Jiffy pellets, a dome, water and light.”

Read Carol O’Meara on her blog,

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