My list is based growing in the ground (not raised beds -- this is my experience). If you're growing in raised beds, you may be able to start a week earlier (they will warm up faster). If you need to build beds, you'll need to have those ready before you can start anything.
I can't give exact dates, because individual locations vary widely in what can be done at different times, but I will tell you the signals that tell you when you can do the different tasks.
I highly recommend a good reference like Ed Smith's "The Vegetable Gardener's Bible". It provides concrete planting times (based on frost date) for all the common backyard veg crops, and Ed is from Vermont, so his climate is similar enough to yours that the advice still applies. (I'm in NH.) I mention some vegetables below, but consult a good reference for info specific to what you're growing.
- Ideally, in the fall you will apply manure to the beds that will be growing "hungry" crops. (Tomatoes, corn, cabbage-family (brassicas), and squash-family.) This is also a good time to plant cover crops. Mulch may also be added.
- If you have fruit trees, late winter is the time to spray.
- In the spring after the ground thaws, wait until it dries out enough so that you can till without making clumps. The point of tilling at this time is to kill cover crops that you planted the prior fall, to incorporate manures that you added, to incorporate mulch that was added in the fall, and to incorporate any crop residue left over from the previous year. (You may opt to go "no-till", but my advice for now is to use appropriate tillage.) Depending on how your raised beds are built, you may be able to use a rototiller, or you can turn them with a sturdy garden fork.
- Now is the time to make sure you have all your supplies.
- Irrigation (not necessarily all of these): hose, watering can, sprinkler, drip hose, etc
- Row cover, if you will
- If you have deer or other pests, now is the time to verify that your
land mines are still "hot" fence doesn't have holes.
- As soon as you have tilled you can plant hardy crops like peas, spinach, and kale.
- (But don't plant immediately after tilling under winter rye -- the rye gives off a chemical that prevents seed germination for a week or two after tilling. I try to plan my cover crops in the fall so that I don't put rye where the spinach and peas are going in the spring.)
- If you have a soil thermometer, it may be useful to wait until the ground warms up to 60F or so; the seeds will germinate better when the soil is warmer.
- You can also "chit" your seeds indoors so that they are pre-germinated when you plant them out. As a first timer, you'll probably have better success waiting for the ground to warm up a bit and planting in the ground.
- Figure out your "last frost" date. Lots of planting times are based on when the last frost happens -- you don't want to plant tender (cold sensitive) plants and have them get killed by frost.
- If you're starting tomatoes and other tender plants from seed, then about 6 weeks before last frost, start these indoors under lamps.
- After they germinate (1-2 weeks), you'll need to thin them and "pot up" to larger pots.
- About a week before last frost, you'll need to "harden off".
- On or after last frost, you can plant them into the ground.
- About four weeks before last frost you can plant semi-hardy vegetables like cabbage, carrots, and chard.
- About two-three weeks before last frost you can plant vegetables like potatoes.
- On or around last frost, plant tender vegetables.
- At this point, you're already harvesting some baby spinach, kale, and lettuce for salads.
- A week or two after last frost -- when the ground has really warmed up -- plant heat-loving stuff like watermelon and squash.
- At this point, the spinach and lettuce may start to bolt. You can plant more heat-tolerant varieties of lettuce to replace the bolted sprint lettuce.
- SUMMER: weeding, harvesting, watering, etc
- When the peas are done in midsummer, pull them out, rake over the bed, and plant a hardy fall vegetable like short-season cabbage, broccoli, turnips, carrots, or kale, or something quick like beets or radishes.
- About a month before you expect the first frost, pinch out the growing tips on your tomato plants so that the plant puts energy into ripening fruit instead of making more vegetation.
- In the late summer/early fall, watch the forecast for frost warnings. When a frost is imminent, you can either cover your tender crops (tomatoes, peppers, etc), or you can harvest everything (even the green tomatoes).
- When the frost hits, pull out all the tender plants.
- If you had any disease, dispose of the plants; if you were disease-free, compost them. Rake over the space.
- Take soil samples to send to your cooperative extension service for testing. Then you'll know what to add for fertilizer the next spring.
- Where you expect to plant "hungry" plants the following spring, apply rotted manure.
- Where you expect to not be planting early plants like peas or spinach, plant winter rye or some other suitable cover crop. (I favor winter rye because it's cheap, widely available, reliable, and hardy; other covers are ok too.)