Last fall I planted some garlic in early October and then we had two weeks of 80 degree weather. None of it came up. This year, I waited until yesterday and planted three rows. It's late October, late by most standards for planting fall garlic, but I didn't want to lose them again. We like to practice crop rotation (less of a production than you'd think for a backyard garden). Crop rotation is good for preventing disease and also takes into consideration the nutrients left behind in the soil from what was previously planted there. We tend to move soil around too, because we're still expanding our garden with more raised beds the previous spring (having hauled two trailers full of compost while 9 months pregnant in May). After a bit of research, I found that most crop rotation plans suggest planting garlic after tomatoes. (Tomatoes shouldn't be in the same spot year after year. They should have two years in-between so that they are in the same spot only every three years. Also, other nightshades like potatoes or peppers shouldn't follow tomatoes either).
This year I planted some garlic we'd bought from the farmer's market and some we'd bought from the grocery store. I figured two types might make a difference. Last year I bought some from a catalog but they rotted before I got them in the ground, and then the garlic I bought from the local garden shop didn't come up at all.
I'd also heard that turnips and parsnips can be planted and then harvested in the spring when planted in fall (we're up in zone 4a here). I did plant some seeds several weeks ago, but nothing. None of our parsnips came up at all this year. It wouldn't be so bad if I could find them at farmer's markets but I can only find the ones covered in wax in the grocery store. I have already decided to give up on carrots because they are easily found at the farmer's market during any time we'd be able to produce them and our nutrient rich compost makes for forked (but very small) carrots. The turnips (and lettuce and kale) at farmer's markets are much better than we'd produced too - I'll leave those to the experts. But, I've got to continue to try for the parsnips.
Our kale, which I'd heard tastes better after a frost, is very small but growing (the rabbits got to most of it a few weeks ago). Now that it's past a frost date, I may harvest what little we have. Every time I say that our harvest is over, I remember that there's still something edible to get out there, and that seems to be true until the snow flies.
Last year I planted some tulips bulbs in the fall, but this year I have no desire to plant more. I enjoyed them when they came up until the rabbits bit off the tops. If those come back up, I'll enjoy those too, but I would rather spend my daylight hours playing with our daughters since we spent so much time on our garden over the summer. It's time for rest and relaxation.