Well, they ARE both Lamium. I didn't look up the botanical name of Dead Nettle or I would've realized that. And yes, henbit is smothering lawns all over the place here as well. Or maybe it is dead nettle ....

Well I'd ALSO urge against chomping on anything before you have a 100% ID - and some asian plants can be OK cooked but not so without careful prep. Anyway after stopping my fingershaking, I'd suggest it looks like some sort of hibiscus and maybe hibiscus sabdariffa or "roselle" or whatever passes for it - and in that case I didn't know the leaves were edible (WE STILL DON'T KNOW THAT) but the flowers/fruits certainly could be. Here is a link that might be useful: roselle- sour leaves

i'm actually really surprised it wasn't ID'd either, especially when you consider the competency i've experienced with the people i'd asked in the past (although the near-dozen people at Lowes, Home Depot and Ace weren't expected). i think the problem was my inclination to suggest i thought it was some variant of eupatorium. i think if i would have broken a leaf off and smelled it, i would have figured it out on my own - this is what worked for the two anise hyssop that came up on my side yard unexpectedly, and the tomatoes too. why wouldn't one of the MGs do the same, i wonder? either way, i really appreciate the ID. it's beautiful. if it wasn't such a profuse seeder, i'd put it in one of my raised beds with (the profuse seeding anise). maybe i'll do it anyway and try to control by pulling the seed heads. :)

Well, it is a little odd that you're only seeing this problem in some plants. That is, you'd think any deficiency would be common for everyone in the bed. There are many strategies for adding these nutrients Certainly just applying some broad spectrum fertilizer like MiracleGro can't hurt. But if you're serious about gardening, I'd recommend that you get a soil test done. Then you can work with facts. Now, I don't believe CA extension services do these tests, so you'll have to find another provider. Maybe someone from CA could weigh in here. FWIW, pure seaweed fertilizer has ZERO phosphorus. I'd look at the NPK rating on it, and see what it's got. Because of that, phosphorus is sometimes added to make it more complete. As to water, you don't want soggy soil, but Brassicas do like moist soil. Now, overwatering in a grow bag is kind of hard to do. They drain readily.