I've already winter sowed 40+ milk jugs, mostly seed types that need a cold, moist period to germinate. They're sitting outside. We've had a couple nights when the temp dropped into the low 20's so they're frozen. Unless the warm weather continues right into early January I'm not worried about the ones I've done so far. I know from the Zone Wars others are busy sowing lots of containers as well.

Chances are the flats aren't deep enough. I fill the bottom half of the milk jugs with 4+ inches of growers mix because winter sown plants have amazing roots. Have a look:

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Those are gaillardia/blanket flower sprouts I took out of a milk jug back in June. I was going to pot them up but one look at those roots and I found a spot to plant them in the ground. I figured they'd be potbound within days!

What seed types are you going to winter sow? I've only done trees, shrubs and perennials so far. I don't normally do annuals or vegetables/tomatoes until March since they don't need the cold.

Oh I see. Thanks :) Yeah, I think I'm mostly going to be sowing perennials and maybe some trees for fun. For perennials I'm looking at Baptisia, Blanket Flower, Canterbury Bells, Columbine, Shasta Daisy, Painted Daisy, English Daisy, Delphinium, Foxglove, Heliopsis, Hollyhock, Lupine, Malva, Pincushion Flower, and Rugosa Rose. For trees, I may try Apple, Cherry, Crabapple, Dogwood, Lilac, and Pear.

I guess I'll save the flats for the Spring then for starting my annuals?

I've seen a ton of your pictures. Your gardens always look so beautiful. I hope mine gets like that eventually! :)

Generally speaking, seeds requiring cold stratification only have to have relatively extended periods of 40ðF or below to do the deed.

Your list is fine. I would hold off on the Pincushion flower and Malva. I would sow them in March or April.
I started mine today, I sowed the Delphiniums.

Thanks everyone :) I cant wait to get started!

bbfan10 - other than the heliopsis, your list looks a lot like mine did the first year. My dogwood trees from that year are now just under 30" tall. Most everything sprouted with high germ rates except for columbine. I grew apple and pear last year for a neighbor. This year I'm growing apple, dogwood, Japanese red maple, threadleaf Japanese red maple, beauty bush, red twig dogwood, spirea & St. John's wort in addition to perennials including Baptisia sphaerocarpa 'Screaming Yellow,' white baptisia, pink turtlehead, Japanese anemone, crocosmia 'Lucifer,' hardy geranium & Jacob's ladder, among a long list of others.

Glad you enjoy the photos. Posting them always makes me see the garden through others' eyes since I can see all the "areas in need of improvement" & work that needs doing. They are definitely coming along but they want to look like nan6161's garden when they grow up. Mine are still crawling on hands & knees.

I guess I'll save the flats for the Spring then for starting my annuals?

Why give annuals less soil to grow in than perennials? Annuals are garden workhorses that bloom non-stop from Memorial Day until the first frost and some even beyond that. Alyssum bloomed here until Thanksgiving last year. I winter sowed annual seeds same as for perennials. I don't do a lot of annuals but they develop roots same as perennials. I don't use flats for growing anything from seed now I've learned about winter sowing.

"Generally speaking, seeds requiring cold stratification only have to have relatively extended periods of 40ðF or below to do the deed."

Yes but here in the OP zone that is also mine we were an avg temp of 50 for the month of Dec so I have not WS anything yet. I have self sown poppies and echichina that sprouted in Dec it has been that warm here.

Here is a link that might be useful: http://www.accuweather.com/en/us/north-dighton-ma/02764/december-weather/2089444

"Yes but here in the OP zone that is also mine we were an avg temp of 50 for the month of Dec so I have not WS anything yet. I have self sown poppies and echichina that sprouted in Dec it has been that warm here. "

Plants which self-sow in your garden drop seeds anywhere from late Spring to late Fall. Some of them spend months in less than ideal stratification conditions before it gets cold enough.

But...some commercial seeds that might need long cold strat, or fluctuating temps for a long time, don't necessarily require the same conditions to overcome dormancy if very fresh. Commercial columbines need months to sprout, but when my plants drop seeds naturally they sprout in days.

Karen

In San Franciso, winter highs are generally in the high forties/low fifties and lows are in the high thirties/low forties. -Seeds that require stratification to germinate do just fine under those conditions.

susanc - you mean to tell me I'd have these amazing results even if the temp here didn't go down to minus 19 degrees every winter? I could easily live without the extreme low temps we get here in CT. And yes, I'm aware it gets plenty colder in other parts of the country. The 5-day forecast is calling for a low of 4 next week.

Note 1 to self: add layers of polar fleece. Note 2: find & put on wool socks. Note 3: bring in more firewood after completing Notes 1 & 2.

But...some commercial seeds that might need long cold strat, or fluctuating temps for a long time, don't necessarily require the same conditions to overcome dormancy if very fresh. Commercial columbines need months to sprout, but when my plants drop seeds naturally they sprout in days.

Exactly, fresh seeds from my columbine drop in time to get established for winter.poppies and ech from stored seed always seem to take forever to sprout. I was suprised to see them sprouting in Dec....

susanc - you mean to tell me I'd have these amazing results even if the temp here didn't go down to minus 19 degrees every winter?

Yep, but you would have a hard time getting peonies or lilacs to bloom, you would have to grow tulips as annuals, and you could only grow low-chill requirement varieties of apple and cherry trees...

P.S. I envy you your summers. Supposedly Mark Twain said, "The coldest winter I ever spent was a summer in San Francisco."

Susan, Mark could have said that about here, too :)

Lots of weeks our average temps in winter (day/night) will be somewhere around 40. At some point WS seeds will usually get some frost or a couple of days of freezing but it isn't necessary. BTW - Peonies bloom without problems, but my crape myrtle Zuni won't, too cool to set flower buds.

Tomatoes could sure use a little boost in summer though, it's a race every year to see if they have enough summer heat to ripen before first frost.

I was planning to try winter sowing this year too, but the weather has been very... odd. It hasn't been consistently cold. We'll get a night in the 30s and then a couple in the 50s. Yesterday almost reached 60s and I had to open the greenhouse to cool it off (aphid problems). I did sow a few containers a week ago. Fearing they might sprout early, I'm probably not going to finish WSing until later this month after I clear out the hoophouse to make room for any early sprouters.

Last year we had a snow storm the night after Christmas, and this year we've begonias, delphiniums and roses blooming in January. Hyacinths are popping up now. A light frost finally got the angel trumpets, lilies, and vinca. Oddly enough, the lantana right next to the angel trumpet is still going, albeit without blooms. A friend's gardens were taken out by frost in November, and he only lives roughly 1 mile away. It's amazing how things work...