You can only plant garlic and some onions such as multiplier onions this month or the next in Zone 6, for harvest in July-August. Arugula will come up but not be ready before a killing frost. But you can manure the beds.

Agree it is too late in your zone now except for the garlic and onions unless you plan to grow under cover. If you have a protected area close to the house that you can cover easily as needed then try some leafy greens but you'll need luck too.

Much better to spend this time getting the garden ready for next year and planting spring flowering bulbs.

Dave

It's true that garlic is the only vegetable left on this year's planting list, but you can still plant cereal rye as a cover crop. And you can use veggie beds as a nursery area for hardy annuals sown from seed like bachelor buttons and chamomile. If you can find plants, now is a good time to set out all kinds of perennials, and bulb planting season is starting. Lots to do while your new veggie beds are in a state of becoming.

Thankyou for the feedback! I'll work on constructing my bed for now and getting some garlic and onions in the ground! I may also do some bulb flowers for spring. thanks again. - Katie

You might have a chance with collards. They can get well into the teens without any damage.

Although collards can take low temps when well established, I think they would need to have been planted a while back to be worth growing over the winter. If planted now they wouldn't reach much size before being stalled by the temperature. Mine have been in since July and I'm picking now. Strange time of year: we're eating beans, zucchini and kale.

Collards have zero chance. We have already had 3 freezes in Zone 6.

I am in zone 6b (one frost) and i will be planting lettuce, spinach, arugula(growing already), radish, carrots. I will use a floating row cover, and a cold frame. There is a good ref book - Year - Round Vegetable Gardener, Niki Jabbour.
Using the row cover takes a little more work and planning, but it give you a little extra time.

Here is a link that might be useful: Floating Row Cover

I agree about the collards, but I would use transplants & cover them with paper the first few frost.
A small hoop house, even with open end would help some.