Mindy, I'm not sure what the benefit might be you are trying to achieve. It's not quite the same as what they would be exposed to naturally, which would be fluctuating temps, bathing rains, snow following by melt in some areas.

Our climates are very different, but where your containers are triple wrapped so to speak, my own are completely open to the elements with nothing on top other than some added grit. I can get away with that in my always-rainy climate because my pots are not going to dry out - but still, I'm having trouble understanding why you are affording them that much protection. It may work, I haven't tried it, but how will you water if that becomes necessary?

Supposedly 3 layers can add two zones...and they will be easy to water. I just have to move a couple of bricks and there are arugula and broccoli that get watered periodically atm. So my goal is to increase speed of sprouting and speed of growth by theoretically moving them 2 zones south.

Well, if that may get you some earlier sprouting then fine, but it isn't what most winter sowers do. We just put the containers outside and let Ma Nature take care of them after that. WS should be less work, this seems very involved. How do you regulate the heat inside your containers since they're triple wrapped?

How does this zonal change square with planting out? Hardening off? Seems like a lot of effort for questionable results.

Bakemom: they would still go out at normal timing for zone 5, the hope would.just be that they'd be larger plants and sooner.

Trudi: maybe I'm not explaining it very well. I put them inside a bed that is covered with a low tunnel essentially. The low tunnel is there regardless because they are for early spring veggies. So there was.no extra effort to put them in there aside from lifting up the fabric and plastic. The temperature woo be controlled the same way as.the beds. I just open an end if they need venting.

I've only sown perennials and biennials so far.so I figure maybe they'd.be ok anyway because that's similar to whY they'd go through.in.nature....?

No, it's not similar. In nature the seeds are where ever they fall or are blown by winds and they germinate when mother nature tells them to which is not within a covered area that is providing as much excess warmth as you would be with all the extra covering that you are talking about.

Also in nature, the seeds are fully open to the elements of mother nature, snow, rain, sleet, sun, clouds etc. which provide all the necessary requirements for the seeds to germinate.

The containers that we use for WS already increases the soil temp a small amount, but what it really does is contain those seeds in one location so that they germinate where they are placed instead of at the mercy of mother nature and where mother nature may or may not have them travel.

this idea may or may not work, but at the same time, you can not plant out before the proper time and you would think you would have to "harden them off" as they are not germinating in a "natural environment and temperatures" that are part of your zone and especially your yard and garden beds.

What you are describing doing, at least as I read it, is to create an outdoor location to attempt to circumvent the indoor light setup for growing under lights, have the room that can go with wintersowing, yet have, at least some of the control of growing under lights; i.e. the earlier germination and plant size when it comes to plant out time.

So there was.no extra effort to put them in there aside from lifting up the fabric and plastic.

Now I'm a bit confused. Fabric? is there fabric covering your seedlings as well as plastic or was that a typo?

If there is fabric covering your containers than I don't see how they are going to germinate at all. Why would you have any of your seeds covered with fabric and then plastic?

The temperature woo be controlled the same way as.the beds. I just open an end if they need venting.

I don't understand how this idea would work to control the temps in your covered containers.

You have already increased the temps of the soil by putting them in covered containers. Adding extra plastic covering under a tent and possibly fabric as well, increases the temps for sure, but just lifting fabric will not do much to decrease the temps in those containers very quickly.

Containers heat up rapidly without much effort when covered. Adding all this extra covering will no doubt cook seedlings, possibly rot the seeds from fungus before they have a chance to germinate and sure will not help with a mass excess of condensation that would occur, far more than is normally expected in the containers.

when temps get too warm with the containers just exposed to the elements, as we normally do with WS, we need to open the containers so that seedlings and plants don't cook in the heat, or move them out of the direct sun they may be in, or let some of the excess condensation evaporate.

Having them all under some kind of covered raised bed, as you have described, sounds like a heck of a lot of work in an attempt to gain a few weeks in seedling size and the end result may or may not make a difference in the long run.

WS seedlings are super hardy, have super strong and large root structures that are not seen on any kind of plants that are forced germinated under lights vs letting mother nature do the work for you.

You sound like you are trying to combine both ideas into one and do it outdoors, but what you are describing is more of an artificial forced germination vs letting mother nature do the job for you and hence you may not get the results that the rest of us get with WS.

What you could do, and I think would be a really good idea to determine how well your idea will work is to sow some of the seeds as you have described and some of them as we normally would WS the seeds.
Then come fall you can compare the results and decide which way works better, if one way did work better for you than the other or if there was no difference.

But, as Trudi said, WS is supposed to be easy, and you are describing an awful lot of work to me as well.

Fran

Mindy - eliot coleman - the father of protection (wow - that sounds kind of mafioso doesn't it????) has said that the decreased light with each layer is a problem, and he stops at 2.

However, as this is just for germination, If you already have the protection up and in place, why not try it? The agribon is vented by design of course - make sure your containers and the plastic layer are vented to let excess heat escape - and then I would think it would work.

The other side is if the sedlings get too advanced, too soon, and crowd in the containers?

What about trying some of the most hardy with the triple protection, and some regular, and see what you find out.

I think that's what ill do t-bird. I was going to say something about the decrease in light in relation the heat as well but wasn't quite sure it would make sense.

The seeds will sprout earlier. Depending on your climate you may need a heat source to protect against freezing temperatures. An unheated structure will get down to the outside temperature.

I don't see why it wouldn't work just fine. As long as the temps don't get too high and the plants have air circulation and adequate hydration, It would be great if you could speed things up a bit.

Martha

++ on the air circulation. Last year tiny sprouts, long wet cold spring, & had algae + mildew growing inside milk containers. When the tops were removed it helped tremendously. Increase that air flow & don't protect the baby sprouts more than the jugs!

It sounds like you're using hoops and covers to extend the growing season and get them to sprout earlier. Lots of people do that, but without winter sowing. Yours is more a combination of WS/season extension, then. The decrease in light from too many layers is something I had never heard before and is now tucked away safely in my brain for future reference.

I'd suggest as an experiment doing duplicate plantings of the same seeds as true winter sown, leaving the pots with one layer and fully exposed, and see what the difference in growth rate is. I'm curious to know if it makes a difference.

If the rows are too long opening both ends might not be sufficient for venting. Maybe keep a thermometer in the middle area and keep an eye on it? The worst that would happen is you need to lift the middle area, or the entire thing, for a period of time.

As a winter sower I look for as little work as possible for the greatest return. Which is why terrene is turning me into a 2-liter sower from an aluminum flat sower-once I have my collection of containers I'll no longer need to save them.

If this method works for you and the effort to you is effortless, then have at it and enjoy. :)

And let us know how your sprouts do!