I’d say anything under 30% should be good. We’re a few hours to the west of you so not exactly sure about Houston. More than that and things might get leggy.

With brassicas (looks like you have kale there) if they get buggy I just pull off all the big leaves, give them to the chickens and let all of the stalks regenerate in fall. If space is at a premium then cut them out and replant with summer veg.

Hope that’s helpful