Cheyenne Garden Gossip

Gardening on the high plains of southeastern Wyoming

Winter sowing


Winter sown seeds 3 - Michelle Bohanan - by Barb Gorges

Laramie County Master Gardener Michelle Bohanan displays one of the milk jugs she uses for winter sowing.

Published Mar. 6, 2016, Wyoming Tribune Eagle, “Winter sowing starts garden at perfect time.”

By Barb Gorges

When I asked her for tips on starting perennial seeds this spring, Laramie County master gardener Michelle Bohanan said, “winter sowing.” I soon discovered it is an increasingly popular concept and practice.

Winter sowing is what our native and other temperate zone plants do naturally. After they set seed, the flowers and fruits dry. Within months or years, they either shatter and release the seeds, a messy bird picks at them, or the wind blows them. You might shred a few dried flower heads yourself from time to time.

The seeds eventually come in contact with the ground where they are subjected to moisture and cold. That, and the cycles of freezing and thawing, eventually break the seed coat which is necessary if it is tougher than the strength of the seedling.

Surprisingly, many seeds require light to germinate. Day length, or cumulative solar warmth, tells them when it is safe to sprout.

With our occasional spring snowstorms, it’s good that not all seeds, even of the same variety or species, require the same exact amount of light and heat. If the first up are frozen out, the slower germinating fill in behind.

Of course, the plants that have winter sowing down to a fine art are the weeds.

The problem with merely sprinkling seed over your flower bed is that seed is expensive and you don’t know how hungry your local birds and mice are going to be.

It occurred to New York state gardener Trudi Davidoff to safeguard her winter sowing by seeding in shallow, covered containers she set out in her garden. In spring, there was no need to harden off the seedlings since they were already acclimated to the outdoors. She merely transferred them into her garden. Another benefit? No need for grow lights or heat mats. She’s been spreading the word since.


Winter sown seeds 1 by Barb Gorges

Cut the milk jug just below the handle, forming a pot 4 inches deep, and a separate cover. Photo by Barb Gorges.

How to winter sow


I visited Bohanan on a nasty day in January with half a foot of snow on the ground. I brought along a translucent plastic gallon milk jug and a little packet of alpine aster seed I’d received in a seed exchange.

With a pair of heavy-duty scissors, Bohanan punctured the jug just below the handle and cut all the way around, creating a 4-inch high pot and a separate cover. She put in about 3 inches of her favorite commercial potting soil, already moistened.

Next, she spilled a couple dozen seeds onto a plastic container lid and with a toothpick, sorted through them, kicking out any unfertilized seeds. They look lighter because they don’t have the germ of the seed needed for germination.

Winter sown seeds 2 by Barb Gorges

Seeds that require light to germinate are placed touching the surface of the potting soil. Photo by Barb Gorges.

Like many small seeds, these require light, so Bohanan gently pressed 16 into the soil but didn’t bury them. Then she forced the upper half of the milk jug, upright, into the bottom half to protect the seeds, leaving off the jug’s cap.


In other, wetter climates, the top and bottom can be slashed to allow snow and rain to water the seeds and then drain, but in our drier climate, Bohanan has had, over seven years, good results without making additional openings.

However, I found I had to puncture the bottoms after the snow on top of my jugs began to melt.

On the Internet, a search for “winter sowing” shows many kinds of recycled containers. The bottom needs to be at least 3 inches deep for the soil and the top needs to clear the soil surface by at least 2 inches. The top also needs to be clear or translucent. You provide adequate ventilation and drainage openings as needed.

On the jug in permanent marker Bohanan wrote the name, source and number of seeds and the date of planting.

Winter sown seeds 4 by Barb Gorges

The planted milk jugs can be safely left out in the cold and snow. The seeds will sprout in the spring. Photo by Barb Gorges.

Back at home, I put the milk jug in a snowdrift on the northeast side of our back fence. While I wait for spring, I’ll empty more milk jugs and try planting more seeds.


Bohanan already had 35 jugs going and figured she was only 25 percent of the way through her winter sowing plans.

This technique is easier than my experience last year sprouting orange butterfly weed—a type of milkweed. I had to leave the seeds, planted in moist potting soil and covered with plastic, in my refrigerator for 6 weeks to achieve “stratification,” the term for this cold treatment.  Other seeds need scarification, scratching a break in the seed coat, and this winter sowing method can help.


While seeds left lying on the ground require no help from us, ones in containers do.

Bohanan’s milk jugs have the opening at the top, plus the gaps where the upper part of the jug is pressed into the bottom, that allow for some snow and rain to seep in and some heat to escape when it warms up in the spring. She forgoes slits in the bottom because she puts some jugs in her unheated sunroom and would rather not have them leak on the floor.

However, she does check her jugs regularly to make sure they don’t dry out, especially the ones under cover of her hoop house. She can tell by the lighter color of the soil (although this doesn’t work for all potting soils), or she can lift the jug and tell by the weight if it needs watering.

Knowing how much water to add might be a trick, and if you think you might be prone to overwatering, you should probably add bottom drainage openings.

When the weather gets warm, to keep seedlings from baking, it is necessary to pull the top off and prop it on the bottom diagonally or even remove it entirely during the day.

Timing and location

All of this still sounds easier and cheaper than setting up lights or buying starts next spring. With our last frost nearly three months away, there is enough time to accommodate even seeds that need 8 weeks of cold.

But figuring out where to put your jugs is also important. Placed along the south-facing wall of your house may cause some seedlings to sprout too soon. Along a north-facing wall may delay them. But the mini-greenhouses are easy to move. Just experiment.

What to grow

Try native perennials from our northern temperate climate, Zone 5 or colder, especially if you are turning your lawn into bird, butterfly and bee-friendly habitat. Popular flowers include varieties of penstemon, coreopsis, milkweed and gaillardia.

Try cold-tolerant vegetables from the cabbage family, herbs and flowering annuals, but probably not slow-starting annuals like petunias. It would take all summer for them to finally bloom.

The seeds of tropical plants, like tomatoes, eggplants and peppers, may also get started too late to produce before first fall frost. Instead, see tomato growing advice archived at


Winter Sown, Trudi Davidoff’s site.

Dave’s Garden, Gardeners all over the country have recorded their success winter sowing a variety of plants, but be aware of what zone they report from.

Alplains, This catalog specializes in native plant seeds and has essential propagation information. However, use the following website to translate the Latin names.

The Missouri Botanic Garden’s Plant Finder, This is one of Bohanan’s favorite sources of information.

Typical native perennials for the Cheyenne, Wyoming area: Blanketflower, Gaillardia spp.; Gayfeather, Liatris punctata; Tickseed, Coreopsis spp.; Beardtongue, Penstemon spp.; Black-eyed Susan, Rudbeckia spp. All photos by Barb Gorges.

7 Seed Starting Secrets


Seed starting aids

Seed starting aids, photo by Barb Gorges

Published Feb. 16, 2014 in the Wyoming Tribune Eagle, “7 seeds of knowledge: It might be cold outside, but now is actually a great time to start your garden by planting seeds indoors. Here are some helpful tips.”

By Barb Gorge

Why start seeds?

“It is so much fun to grow your own stuff,” said Barb Sahl, who teaches Laramie County Master Gardener classes.

Plus, you can grow varieties that may not be available at local nurseries. Best of all, you can time their growth so that they are the optimum size for transplanting to the garden.

Yes, even though it looks a lot like winter, now is actually a great time to start your garden.

Step 1 – Read the seed packet

Get seeds that are in packages dated for this season. The older the seeds, the less likely they will germinate.

Look for short-season vegetables so you can harvest before frost.

The “Silvery Fir Tree” tomato that I tried last year is supposed to produce a ripe tomato in 58 days after transplanting outdoors.

Most vegetables have short-season varieties available, even eggplant. “Orient Express” is rated for 58 days to maturity, and “Marketmore,” a cucumber rated for 60 days.

Cheyenne native Willi Galloway, author of “Grow Cook Eat,” recommends 75 days for our area.

Check to see if seeds are better directly seeded in the garden—some don’t transplant well.

Look for how many weeks before the last frost you should start seeds indoors. Our average last frost date is May 24.

The packets will also tell you proper planting depth. For tiny seeds, it is so scant, place them on the soil surface, sprinkling a little dry soil on top and moistening with a mister.

Check to see if your seeds need special handling. To germinate, some need soaking or nicking or exposure to direct light or to sit in darkness. Some even need to cool in the refrigerator.

Seed-starting medium

Seed-starting medium, photo by Barb Gorges

Step 2—Use seed starting soil

Kathy Shreve, another Master Gardener mentor, is adamant about buying special soil designed for starting seeds. It’s available in most places selling gardening supplies. You will have a higher rate of success because it’s sterile—it doesn’t carry fungus that can kill seedlings, and it’s lightweight so the seeds don’t have to struggle through the heaviness of typical garden soil.

I don’t need a lot of this special mix. Once the seedlings have several true leaves, not just those first two “seed leaves,” I can move them into larger pots with regular, cheaper, potting soil.

Because the seed starter soil is super-dry, be sure to mix it with water before filling the pots.

Accelerated Propagation System

Lee Valley’s “Accelerated Propagation System,” photo by Barb Gorges



“Accelerated Propagation System,” showing water reservoir and wicking system, photo by Barb Gorges

Step 3—Use sterile pots

Kathy and Barb both swear by “accelerated propagation systems.” There are several brands, but the one we use is from The clear plastic dome keeps the soil surface moist until the seeds sprout.

But the water reservoir is key. A wicking system waters each cell from below so that seeds are never jostled from top watering. And before seeds sprout, the reservoir may not need filling for several days, letting you take a vacation before the more demanding part of plant parenthood begins.

Because the seedlings require only a few weeks before they need repotting, I have been able to start all my small seeds in shifts in this watering system, which is the size of an egg carton. More robust seed varieties do well in other containers covered with plastic wrap until they sprout.

I scavenge for my other containers, carefully reusing plastic pots from plant sales and nursery purchases, as well as whatever stores throw out. It’s appalling how much plastic waste the horticultural industry produces.

Any container you can sanitize can be reused—styrofoam cups, tall drink cups (especially for tomatoes), yogurt cups—just be sure to poke a lot of holes in the bottom for drainage. Clean them and then soak them in a 10 percent bleach solution for a few minutes, then rinse.

There are pots made from compressed fibers of various kinds. The idea is that you can plant the pot and all right into the garden and the roots will grow right through the walls. My experience is that the roots stay in the pot. It is better to tear it away when transplanting and throw the pot in the compost pile.


PotMaker makes pots from newspapers, photo by Barb Gorges

Last year I tried the “PotMaker,” a little wooden cylinder that you roll a strip of newspaper around several times, fold the bottom inch or so underneath and crimp the fold. Remove it from the cylinder and fill it with potting soil. If handled carefully, or rather not handled after setting in a plastic tray, these little pots will hold up until the plant is ready for transplanting outdoors. While newspaper is degradable, I prefer to remove it, if there aren’t too many roots already growing through it.

You could use any cylindrical object to make the size pot of your choice. Wrap the paper around two to three times, but not so tightly you can’t slip it off. And use a freshly read newspaper—nothing that’s been sitting out for weeks accumulating disease spores.

heat mat

Heat mats provide heat under a flat of seedlings, photo by Barb Gorges

Step 4—Provide bottom heat

Some types of seeds, such as vegetables of tropical origin such as tomatoes, peppers and eggplants, are happier with warmth from an electric heat mat placed beneath them. Vegetables from cold climates, like cabbage and broccoli, don’t care so much. Yes, this is an investment, but especially necessary if you are starting your seeds in a chilly basement.

Last year, I dispensed with the heat mat when I decided to start my seeds in the hall bathroom instead of the basement. It has no windows, just a skylight, and is the warmest spot in the house—over 65 degrees. No one uses the bathtub now so I put in freestanding shelves and hung up lights.

Step 5—Provide extra light

“A windowsill is hardly ever sufficient to grow good stocky seedlings,” said Kathy.

Catalogs are happy to sell you special grow lights, but for the brief time seedlings are with you, a 4-foot shoplight with two fluorescent bulbs, 5000-6500 degrees Kelvin (daylight is approximately 5,600 degrees), is adequate for two standard 10-by-20-inch flats.

Turn on the lights when you get up in the morning, and turn them off at bedtime.

Keep the top of the plants about 1 to 2 inches from the light bulbs. Either hang the lights on chains so that their height can be adjusted, or stack stuff under the flats to bring them close to the lights.

Step 6—Provide wind

Really! Both Barb and Kathy keep small, ordinary oscillating fans going across the room from their seedlings. It prevents damping off disease, when seedlings keel over and die.

Also, plants respond to air movement by reinforcing the strength of their stems so you’ll have stockier, stronger plants.

This has worked for me when I started seeds two years ago. Last year, in the bathroom, I didn’t use a fan and didn’t lose any plants. However, Kathy and Barb’s plants did look better than mine.

Step 7—Water and fertilize carefully

More indoor plants are lost to overwatering than anything else. Once your seedlings germinate, take off any plastic covers and make sure the surface of the soil gets a bit dry before the next watering. As the seedlings grow, their watering schedule will change. Plan to check them at least every day.

Most seed-starting and regular potting soils have fertilizer added, so let the little plants chew on that a few weeks before giving them anything more—and then figure half strength of whatever the directions recommend.


Don’t worry if by the end of May your plants aren’t blooming and as mature-looking as the ones at the store. Blooming plants sell better, but often their roots are pot-bound in those tiny containers and the plants, especially flowers, may not really recover to grow much the rest of the summer.

You can make sure your starts aren’t pot-bound and are at just the right stage to jump into the garden and keep growing.

Starting from Seed: Starting seeds indoors

lettuce under lights

Lettuce under lights

Published March 25, 2012, in the Wyoming Tribune Eagle, “Gone to seed: Planting and nurturing a garden from scratch can be one of the more rewarding aspects of the summer season. But keep a few tips in mind before turning over soil.”

By Barb Gorges

My eyes were bigger than my garden when I shopped the seed catalogs last month.

In my quest this summer to cultivate an early tomato from seed, as well as an annual (the dwarf cosmos), I now have 18 packets of seed sorted by when they need to be started indoors. By the way, it is now time to get those seeds started, if you haven’t already.

But some plants do best when seeded directly into the garden. I have five packets of sunflowers on standby, along with seeds for lettuce and radishes.

I’ve done the calculations (number of days to germination, plus two weeks to transplant size before May 24, the average last frost date), or used the information on the seed packet, and marked a spare calendar with the planting dates for each plant.

The earliest is Marine Heliotrope Peruvianum, very tiny seeds, which I started March 1. I’m not familiar with this annual – it showed up instead of a marigold I ordered, but I’m curious. I’m the gardener who lets things sprout in the perennial bed and waits to see what they are—if I don’t immediately recognize them as bindweed or thistle.

There are three factors important to seed starting success, says Shane Smith, director of the Cheyenne Botanic Gardens. They are: sterile pots; new, sterile soil and planting seeds to a depth twice the width of the seed.


Pots need to be sterilized with a good scrub for ones being reused, plus a few swishes in a 10-percent bleach solution.

As for soil, you could bake your own at 250 degrees until it reaches 140 degrees for 30 minutes to sterilize it, but it smells. Instead of garden soil, buy fresh “soil-less” potting soil, which is light and fluffy and usually sterile. If you have time, leave it out in sub-freezing weather for a couple of weeks to kill everything.

You can make your own soil-less seedling mix: 3 parts milled sphagnum, 2 parts perlite and 1 part vermiculite.

For my pots, I’m trying a bag of “Seed Starting Jiffy-Mix.”  It’s very dry and needs to be mixed with water before putting it into the little seed-starting cells—otherwise it sheds any water I pour on it.


The rule of (the green) thumb is plant no deeper than twice the width of the seed (not the length or thickness), Smith says. Seeds have evolved to sprout with just heat and moisture (though a few actually need light, too), but if they don’t reach sunlight before they use up the energy stored within the seed, you’ll never see them.

Master Gardener Kathy Shreve demonstrated how to pick up a very tiny seed: Use the end of a dampened toothpick, and then brush the seed onto the surface of the growing medium.


Pots need to have drainage holes in the bottom. While you are waiting for seeds to germinate, the growing medium can’t get too soggy or too dry.

I was particularly intrigued with Shreve’s Advanced Propagation System. It is a commercially available miniature, self-contained greenhouse, with a tray of planting cells, a clear plastic dome lid to keep moisture in and a water reservoir below that should only need filling every few days.

The ends of a porous mat hang down into the reservoir and capillary action brings moisture across the mat placed under the planting cells where the soilless planting medium wicks it up to the plants.

A less fancy method is to gently spritz the soil surface when necessary and lay plastic wrap over it until sprouts show. Verena Booth said she sprouts difficult seeds the way alfalfa is sprouted for salads, and then pots them. Or try folding seeds in a wet paper towel placed in a plastic bag. It worked for me.


The only sunny windowsill at our house is already full, so I’m using a 4-foot fluorescent shop light suspended over the workbench downstairs. Windowsills are rarely bright enough and ours would be a poor choice anyway since we have low-e glass which keeps out a part of the spectrum and makes my houseplants leggy.

However, Master Gardeners Shreve and Barb Sahl agree that cool white fluorescent bulbs work fine for starting plants. The blue spectrum is perfect for seedlings. Keep the light close to the seedlings, 1 to 2 inches above. If the height of the light isn’t easy to adjust, or you have plants of different sizes at the same time, add blocks of wood or something under the short plants’ pots to get them close enough. Shreve gives her seedlings light 16 hours a day. Sahl leaves her lights on 24/7.


Damping off disease breaks a lot of hearts. One day the brave little seedlings are vigorously reaching for light and the next they are lying flat—rotted off at the soil surface. Sterile soil helps prevent this. Shreve and Sahl also use moving air, a preventive seeds started outdoors get naturally. But it’s too cold to open a window, so try a fan set on low and placed across the room.

The other benefit to subjecting seedlings to a breeze is stronger stems.


Heat, especially for plants of tropical origin—tomatoes and peppers—is necessary to germinate their seeds. The cost of plugging in a heat mat I bought through a garden supply store to put under a flat of seedlings is probably less than turning up our household thermostat to 80 degrees.

A week after planting, 30 percent of my heliotrope seeds had sprouted. Before April I plan to start the tomato and cosmos. If all goes well, I may be looking for ways to hang flats of seedlings under all of our fluorescent ceiling lights.


When sterilizing potting soil by baking it in your oven at 250 degrees, it must bake 30 minutes after the soil temperature reaches 140 degrees.