I have done this outside about froze to death and this year inside. Oh boy I think doing outside is easier. Where do you winter sow?
I am spoiled. I have an unheated greenhouse I sow in. I even put a space heater out there if I get too chilly. So much better than the mess in the kitchen. When Dh got me my first greenhouse I yelled at him ans said I did not need it, Winter Sowing works without one...it is my glorified potting shed.
Always kitchen, and I just dealt with the mess. And tried to time it so DH wouldn't see the process before it was cleaned up :)
I haven't sown yet this year but I have a nice spacious laundry room just off the kithen in my new house with plenty of tiled countertop, good light, and an oversized deep sink with sprayer on the faucet - that's where I'll be when I get organized with life in general to be able to sow. Oh, and vinyl flooring between room and back door, no dripping over anything I can't easily take care of.
There is a cedar garden shed with window, electric lighting, no heat but outlets, no water - I haven't quite investigated the possibilities there. I let DH put garden things away from moving and I'm a little afraid to even open the door for now :)
I've always sown in the kitchen as well. Never even thought about anywhere else - too darn cold outside! I only sow about 6 to 8 jugs at a time, so the mess is manageable.
In an unheated basement. Kitchen not an option.
My house is very small - just a cabin actually - so I have to work out in my cold frame which is 50 feet long and about 6 feet high. I use a small space heater which works well most of the time, but this week with temps in the 20's, I'm not getting a lot done. The weatherman has promised better days ahead so I'm hopeful that I will be able to sow starting again about midweek.
In my messy unfinished dungeon of a basement. Mess can stay for days, doesn't matter.
I wintersow in the middle of my kitchen floor. I spread a cheap shower curtain on the floor and it contains most of the mess. I fill a medium rubbermaid bucket with soil and work out of that on the floor. I use a restaurant bus bucket to transport my jugs outside so there's no dripping.
I wish I had a garage or a mud room to work out of instead.
I WS in my kitchen as well no way im gonna freeze my backside off doing it outside.
Usally takes 5-10 trips to take to take them all outback behind the shop.
I winter sow on the floor of the family room. Spread out a piece of plastic and fill the containers there. The bale of Pro-mix is stored in the garage, and I put some in a 5 gallon bucket and bring it inside.
Sometimes I use a 1/2 pump gallon-sprayer to moisten the potting mix. I've discovered what's even easier, is to put the containers outside on the deck when it's going to rain, and let the rain moisten the potting mix. Then they come back inside to sow!
My son's gone off to college, and I live alone when he's not here (except for a tenant who lives in the apartment), so I can make any mess I want. :)
I fill the containers in the garage then bring them into the kitchen seed where I water, add the seeds, cover the seeds with soil if they require it, then put them on a tray on the island where they get taped then carried out to the patio.
Like Dee I only do six or so at a time so it's pretty easy to clean up.
I also do it when my husband's not home so he doesn't stress out about the mess. He keeps threatening to get me a shed or hot house, but I point out that without electric or water it would not work because I wouldn't use it.
I mix the Pro-mix with water in 5 gallon buckets in the summer and store them indoors so they won't freeze. Now, in the kitchen I prepare all of my jugs and fill with dirt. It isn't messy at all. I cover the table with newspapers but don't find it a messy job.
In mid April I will get out my 16oz. clear beer cups (which I save each year) and sow the tomatoes which I allow to germinate in my south facing windows. I have the peppers on a heating pad. (BTW, with the tomatoes, I only put 2" of soil in the bottom of each cup and 4 seeds. As they grow, I fill since they root all along the stems. With the clear cups you can see the root system.)
Now I like your idea of mixing in buckets in summer RyseRyse! You actually mix the potting soil and the water together in the summer? No bad effects from doing this so early? This step is the worse step I am dealing with when winter sowing (such a mess) so if this will work I am going fill my buckets and water the soil down in late fall.
I agree Mary the watering part is the most time consuming and messiest part of WSing.