seed starting without lights

I am very good at starting plants under lights.  However, my husband and I are trying to minimize our energy consumption, and my new goal is to get very good at starting seeds without lights. My three south facing windows are already full of plants that I bring into the house for the winter. I am fortunate in that I have 2- 8 x 16 ft passive solar high tunnels. Great for shoulder seasons, but I have never tried to utilize them for starting seed. I am zone 5b and currently we are having a mostly mild fall. I am toying with the idea of trying to start onions and leeks now under multiple layers of plastic - tunnels within tunnels - for spring transplants. I have also just set up a community leaf collection site and have lots and lots of fall leaves to use. If anyone has experience, great reference books, youtube links or just suggestions, I would love to hear them.

Don't know if this is helpful, or if you're specifically looking for advice on how to start seeds in the high tunnels, but... The spring before last I started a bunch of seeds in a west-facing window. I did have grow lights, but not enough. When the seedlings started crawling towards the window, I experimented with propping up a mirror behind them, to reuse the light that got past them and make the light exposure more even. It worked decently, they grew straighter, and I started dreaming about making a box or cabinet with one side open towards the window and the inside coated with pieces of mirror-glass, so that all of the light that didn't hit the plants on the way in would be reflected back on them. Don't know if I'll ever do it, but I think it might work. The top would have to be openable, otherwise watering would be a pain, and the pieces of mirror should be angled to focus the light from all directions on the bottom of the box.

Those plants you are overwintering are using your seed starting space.

When I over winter plants I often use my shower or my laundry room where they do not get direct sunlight.

If these plants are not producing flowers or fruit, my opinion is they do not need direct sunlight.

You are the best judge of whether that direct sunlight is needed.

Why not try starting your seeds on those three south-facing windows?

This sounds like a fun experiment.

I'm thinking about the spots in my yard that harbor/grow plants that are happier a zone or two warmer than I am.    They are in sheltered places with windbreaks that get the earliest morning sunlight.  Some have large rocks nearby that I suspect help hold the heat.  Now, I"m not going to be starting seeds out there in February, but I can get a jump on the season putting seedtrays out during the day and pulling them back in at night.   Just tossing out some thoughts on maybe where you try the double insulated covered area (like a cold frame I'm thinking?) ..  maybe placing it in a microclimate that gives it a jump?

I just got a greenhouse this fall.   I'm looking forward to exploring and experimenting with what it allows me to do!  

I've found that it takes no light to get seeds to sprout, and not much light (say, a single 2 ft cool fluorescent) to grow small shoots for immediate consumption. Heat matters more than light.

But I learned the hard way that starting plants to grow large enough to transplant outdoors (tomatoes, for example) need much more light if they are to grow strong stems that can resist wind, avoid being leggy.

I had no success starting tomatoes from seed until I bought a 2-tube LED grow light optimized for plant-growing wavelengths (red/blue). Even then, I have to lower the bulbs until they are sitting just above the seed tray, and gradually raise it as the plants get taller.

Suddenly I was able to grow quantities of tomato starts successfully!

As humans, we don't realize how much brighter sunlight is, relative to almost any artificial light.

I have a solar powered watch. The instructions say that a day's power usage will be charged after 5 minutes of direct sunlight, or 10 minutes of cloudy sunlight...or 8 hours indoors sitting very close to a bright lamp.

Think about what that implies for plants!

Your best approach may be to sprout the seeds in the warm house, perhaps in your furnace room, near a wood stove, or on an electric heat mat.

Then plant the sprouted seeds on a windowsill, even if not south-facing. East-facing will probably work. Once the plants get a little larger and stronger, perhaps transplant them to the outside high tunnels.

This will be easier if the crops have some cold tolerance.

Cathy James wrote:But I learned the hard way that starting plants to grow large enough to transplant outdoors (tomatoes, for example) need much more light if they are to grow strong stems that can resist wind, avoid being leggy.

Cathy brings up a very important example about getting "plants to grow large enough to transplant".

I would imagine that no matter where the seedlings get started without light those sprouted seeds are going to need light.

South-facing windows or artificial lights. East-facing windows will get morning sun and west-facing windows will get afternoon sun so my guess is that these will work if the seedlings can be moved during the day.

I have always had the best luck with just planting my seeds outside after the danger of frost in the spring.

Anne Miller wrote:
I have always had the best luck with just planting my seeds outside after the danger of frost in the spring.

Here in Vermont my frost-free growing season is about 120 days. So for some sub-tropical crops, particularly tomatoes and peppers, starting inside is necessary to get a jump on the season. Most years I would get very little fruit if I direct-seeded tomatoes outside.

However, many plants can be started outside well before last frost, with little or no protection. Peas, lettuce, spinach, mustard, claytonia, and many others can usually be planted in mid-April here, even though last frost is mid-to-late May.

Cold frames and tunnels are great season extenders.

I don't know why, but many gardeners, even experienced ones, don't plant anything until after last frost and are surprised that anyone does. I'm routinely eating fresh spring salads at the time they are thinking about putting the garden in.

It's only plants with no frost tolerance and a desire for hot weather, such as tomatoes, peppers, corn, and beans, that shouldn't be planted until the danger of frost is past.

Hello friends planting is the prime of getting food and fulfilling our requirements seeds are sown under shinny sun light which sustains photobiological process which I get to know more from here stone age farming

I don't use lights. I have a south facing window, a west facing window, and an east facing room. The east facing room has a window I can't use that faces south, and a large east facing window the plants go under. I get my best results there but I only use it for a few weeks because it blocks my freezer.  And I start hundreds of plants every spring.

I rotate seedlings daily. Sometimes twice per day. It helps to have them on trays you can just flip back and forth.  I like to kind of 'pet them' with my hands to gently move the stalks before I turn them. I think it helps strengthen the stems.

I start things in 72 plug trays or even just sown on a tray of soil, and then move them to solo cups as they grow bigger.

I also stagger my plantings - frost tolerant plants (brassicas) are hopefully already being planted out by the time I need to prick peppers and tomatoes into larger pots. And some of my flower and herb plugs I start when I move the tomotos into bigger pots.

As it warms up, I put plants on my south facing covered verandah on days it's not forecast to go under 5C overnight. They get a lot of light there, more than they do in my house. I start then next to the house and slowly move them towards the edge of the porch. Even midway away from the edge, I think they get better light than they do indoors. If I put them right on the edge immediately, they burn. Last year I think they had about 3-4 weeks of being mostly on the porch before we were officially past last frost.

I start squash from seed, but do so on the porch at last frost or maybe 2 weeks before, in solo cups. I find no difference between squash that go into the ground at last frost, and those that go in 3 weeks later. Squash/cucumbers direct sown get eaten by things.

I suspect that (with shade cloth and a willingness to bring things in on cold nights) your high tunnels could be excellent seed starting space.

Thank you everyone for your suggestions!
The plants taking up my window space are plants that I consider to be valuable. 6 year old bay tree, 3 year old rosemary bush, a scented geranium that I have never found again. Plus my bulbs that i force for my garden fix and sanity.
I really like the idea of using mirror or maybe mylar blankets to reflect and bounce light in the high tunnels! Definitely experimenting with that one!
I have a few years of direct seeding hardy crops into the high tunnels for fall/winter/early spring harvest. Seed starting of less winter hardy veg and herbs/flowers is a new one for me.  We start several hundred plants each winter/spring, but the amount of energy we use to run heat mats and lights is significant enough that I want to find a less power hungry way. I consider it a new life skill for my retirement years.

The things I am specifically coming up short on are the crops like onions/leeks that are recommended to be started in January.  I can germinate them in the house. Its the part after that which I am having trouble wrapping my head around. I have been reading Charles Dowding, and he does this with a hot bed in his polytunnel. I think he is a couple of zones warmer than I am though.  I have also watched Edible Acres Youtube where he direct sows seedlings into a warmish polytunnel  and then transplants out, but I dont think he starts until March. I want to be ready to plant out onions/leeks with my potatoes in the very early spring.

I guess I just need to pick something to try and get after it!
At this point I am looking hard at mylar to increase light. 12 inches or more of ground leaves mixed with grass clippings and chicken/duck manure to create a hot bed. and then multiple layers of plastic to keep plant babies warm. Gardening is always one big experiment!!
Thank you all for your suggestions. Wish me luck!

I’ll offer just a couple notes.
1. Seedlings would do fine in windows, but sometimes the direct light can be a bit much when they’re young and tender. Rotating is a good strategy. You can also use something that diffuses the light and breaks up the direct beams. Like a light diffusing window film perhaps.

2. Plants in tunnels are great. Sounds like you can easily keep them warm enough with your plan. Just look out for TOO warm. A few hours on a surprise warm sunny day might nuke them. So it just takes some mindfulness to vent on those days, or get real fancy and incorporate one of those hydraulic panel openers for green houses (automatic, no power, just fluid that reacts with heat to extend an arm.)