What's this little guy called? I expanded my annual beds and built a hugel a few weeks back, and now this plant is popping up along the edges. I don't remember seeing it in years past. I'm in CT, USA, zone 7a.

Kris, it looks a lot like Shepherd's purse; that being said, sometimes watercress can sometimes resemble Shepherd's purse. I'm sure its in the brassica family, though. If you haven't planted cress in the past, with the seeds somhow running amok, it is likely shepherd's purse.

Hmm, I don't think it's watercress.

When I did a google search, shepherd's purse seems to have a clear circle of leaves, kind of like dandelion, and a stalk that looks a bit like mustard going to seed... I'm not sure!

They are also tiny. About the size of a dutch clover.

What does it taste like?

I hadn't tasted it. Just popped outside and tried some. Ben was right about it being a brassica-- it smells and tastes like broccoli!

Ben Johansen wrote:sometimes watercress can sometimes resemble Shepherd's purse

Hehehe double sometimes, so you know its good.

Winter cress?

Actually no, that has yellow flowers.

Looks very familiar to what I normally kill as a weed,
Any smell from it?

We have lots of that. I believe it's Hairy Bittercress, Cardamine hirsuta
https://en.wikipedia.org/wiki/Cardamine_hirsuta

Is apparently edible, but not very palatable.

I have loads of this stuff. It's especially petulant prevalent this spring.

Is it going to cross pollinate with my kale or cabbage?

Cardsmine hirsuta it is. Looks exactly like the wikipedia photo.

I thought it was kinda tasty.

I have been encouraging dutch clover, dandelion, purslane and creeping charlie in the lawn. I think I'll just add this to the list! We have a 2 year old so a little bit of grass is nice for her to run around in, but If we have to have a lawn, I like letting it at least be a polyculture of sorts. I wonder if our mild winter allowed this stuff to proliferate? Maybe there was a little of it before? A closer look revealed tons of it mixed into one area of the lawn as well as around the new beds!

Pros: make pesto out of it, feed the bees in early spring.

Con: attracts aphids? Or is this a pro since it could be a "trap crop"?

https://www.growveg.com/guides/useful-winter-weeds-chickweed-bittercress-and-henbit/

R Ranson:
It seems unlikely that it would cross pollinate with Kale or cabbage, since it's a different genus. We have a LOT of it here that goes to seed before we can get to it, and have never noticed any cross-pollination. It also seeds quite a bit earlier than our brassicas.

Kris: I've never noticed a lot of aphids on it here.

Kevin Wilson wrote: Hairy Bittercress.

High five, Kev. +1 props

R. Ranson, I just noticed today that in just about a month and a half, these little guys have entirely gone to seed and nearly disappeared beneath the other, more vigorous growing things. They certainly did go to seed long before my kale, bok choy, and mustard, which are still just about 6 inches tall, and nowhere close to producing seeds. Kevin's right