Of the ones you haven't tried yet, I have sown:

cukes
delphiniums
cosmos
zinnia

All of these have done very well for me. The delphiniums were a bit more finicky, but it was, if I recall, usually with the seedlings and aftercare, and not with germination. Also, I have trouble with getting the delphs to overwinter. But the actual germination rate by WSing was quite good for me.

I've also sown basil, marigolds, and echinacea with great success. But I can't really give any tips as to what you were doing wrong, because I really just throw the seeds in the containers and stick outside and leave them to their own devices.

I will say that if this past year was your first time trying these, it was a very wet spring here on the east coast, and I know that affected me badly. I lost a lot of many kinds of seedlings. Did you have trouble with germination, or with keeping the seedlings alive? Oh, I will add that I usually start any vegetables and herbs later in the season, like April. I don't know if that makes a difference or not.

Remember the old saying - if at first you don't succeed, try, try again!

Just ask PV and me about kiss-me-over-the-garden-gate, lol!

:)
Dee

I think everything but the marigolds germinated. The basil came up late. And in general I thought maybe I took the covers off too quickly, or too soon, because a ton of my seedlings didn't continue to grow. Disappointing.

Maybe the wet spring didn't help. Thanks!

I definitely will keep trying. It's so fun! And maybe it will be more fun this year since I expect to be worrying less over my baby plants.

And the echinacea didn't come up either. But these seeds were harvested/stored by a home gardener. Don't want to place blame, but maybe that had something to do with it.

Sweet and hot peppers - You're two zones warmer than me, but when I WS them, they germ., but didn't ripen before first frost. Mine are started indoors now.
cherry tomato - WS all of my tomatoes this year, and the first ripe one was earlier than the indoor sown ones from last year!
det. tomato (celebrity)
bush beans - These are heat lovers and will rot in cold damp soil. Either spring sow them using the WS method, or direct sow after last frost date.
*cucumber - not frost tolerant, I'd sow close to last frost date, or direct sow
*Brussels sprouts - Haven't grown these, no one at my house will eat them, LOL
*broccoli - Excellent results wintersowing them, but may not grow this year. They are space hogs, and mine only produced tiny little heads.
*kohlrabi - Haven't grown, but should be great for WS
*watermelon - Another heat lover, plus doesn't transplant well. I'd direct sow after last frost.
*honeydew - Same as above
*canteloupe - Same as above
**basil - I SS a TON of this each year. Not frost tolerant though, so be sure to cover if it sprouts before last frost date. Mine usually doesn't take off until the nights warm up a bit.

*candytuft - Haven't grown
*blue fescue - Haven't grown
*delphinium - Haven't grown
*cupid's dart - Haven't grown
*cosmos - Sow close to spring, not frost tolerant, so if it sprouts will need protection
*zinnia - Same as above
aster
**marigolds - Same as above
**echinacea - WS well, but usually won't bloom the first year

As you can see, quite a few on your list are frost sensitive. It doesn't mean you can't WS them, but just be ready to provide extra protection until after the last frost date once they have germinated.

BTW, my list for next year is already 6 pages long, LOL!

Bonnie

*cucumber- yup
*broccoli-did really well with ws
*watermelon-yup
*canteloupe I direct sowed
**basil- like it hot, starting them early didn't seem to get them to grow faster than the later started ones. They take a long time I recomment a mammoth variety like genovese, mammoth or purple basil.
*cosmos-yup
*zinnia- yup
**marigolds- yes but these really need a layer of dirt as coverage to come up well. They don't like being sprinkled on top.
**echinacea -I've heard a lot of mixed reviews on these, last year my first winter sowing they did great for me. They seem healthy and I can't wait to see how they do next year, colorwise and everything.

My list is a spreadsheet from last year for the things I will be watching in case they come back or grow well and the new things I'll be trying.

WOW! Thanks for the info, Bonnie.

My peppers this year seemed "stunted" for lack of a better word. I can't believe you start them now!

My cherry tomatoes were *amazing* this year, but the bush tomato not so much.

Thanks again. I love how WS'ing makes this time of year, and the cold winter months, exciting!

Ooops! Don't think I worded that right. What I meant was that after that first year, I decided to only start them indoors. They will be sown in March. Sorry for the confusion : )