Early wild greens for homemade dog food?

I've been given a bunch of freezer burned ground beef. It's pretty rich so I'm cooking up "dog stew" to stretch it out and buffer the fats. The stew includes last year's potatoes, carrots, beets, and oatmeal.

(Note this will be 50% of their diet -- they still get good quality commercial pet food.)

Gardening season is a ways off. I'd like to add some "wild" early spring greens to the mix.

Grass: My hounds naturally graze on quackgrass (no chem) on the fencelines. If I cut it when it's young (maybe 4") and chop it up fine, that could be a source of vitamins/minerals and fibre.

Weeds: I'm not sure what would be safe. Don't need a vet bill. Chickweed? Lambs Quarters? Poplar tree leaves?

Thoughts?

Chickweed, in moderation, should be fine, lambs quarters will be great. Not sure about the poplar. Go easy with grass, it's something dogs usually chew on when they feel nauseated, and want to puke - kinda like epicac.

Thanks! These will be added in tiny amounts and cooked. My hounds are large dogs, so the percentage in their diet will be tiny.

I could just ask around for old peas or green beans from people's freezers, but where's the fun in that?

I feed my 2 raw, homemade. Hubby feeds his 1 kibble. I'm not a fan of kibble, he's not a fan of doing the work I do, to make the food. All 3 are omnibus, and will happily eat anything we put in front of them. As long as you're not giving them xylitol, onions or most other alliums,  chocolate, grapes, raisins, pecans, cashews, pistachios, hazelnuts, and a few other odds & ends, they will be fine - even healthier.

Garlic is controversial, but even my vet agreed that just enough that you'd expect random polite company to enjoy it - not a lot, is not only not bad for them, but offers the same heart health benefits, as well as helping fight heart worms.

Some of our dogs favorite training treats are small dices of carrots (in moderation - they're high in sugar), celery, cabbage, broccoli, pumpkin, & cauliflower. Blueberries (in moderation) are excellent for their eyes, particularly helping with the brown, nose-staining eye goo. Strawberries are great, and high in vitamin C - even the tops are great for them. Cranberries are great for urinary tract health, but not so much the sweetened dried ones. I avoid legumes, swapping in walnut or almond butter instead of peanut butter, because legumes tend to be inflammatory and high in sugars.

Sorry - you didn't ask for a book, lol.

No worries, I like books.

During summer we have all the garden veg and fruits in abundance. Or I can buy them at the grocery store now, shipped in from far away.

But our planting season is still weeks away. Our forecast tommorow is a temporary return to freezing temperatures and snow.

So I'm focusing at the early greens I notice popping up in microclimates on my property. Not for a big volume in our dog food, but a spring tonic of greens and the nutrients they may provide (provided they are not toxic). Since this is so offbeat that search engines cannot fathom such a search, I'm asking here.

I have resources, so if you have a question about a particular plant, just ask. By the way, bananas, as a very occasional treat are always favorites, and healthy - just high in sugars, so very limited.