I can't seem to get the four plants mastered?? any new advice??

Just keep plunking one of the people on it. I usually start with the rose or the lily. Once they get those two then the other two seem to take that person less work.

still trying and no luck

I've found that the cactus is the easiest and once they've studied that a couple times then the others are easier. Look for the message at the bottom that says "villager improved at healing."

Funny, I find that they have the hardest time with the cactus. Once they get the others first then they can get the cactus. The only time they got the cactus first when it was their choice to study it. Not because I plonked them there.

I restarted the game once, but both times the first they did was the green one on the left. I kept plonking them there and voila. Actually the first game, the one I restarted, I used different villagers for the plants and it still worked. The second was the fruitless plant, then cactus, then the others.

Man this one was one of my easiest ones.

I've just gone anticlockwise starting with the rose each time I start a game, and they figure it out no problem. It usually only takes a couple of goes at plonking them down.

I wonder whether having their skill preference set to healing makes a difference, as I've always had my healer go and do the herbs as soon as they've cured that first villager who is sick.

I start at the rose, if that villager doesn't get it I move on to one who does. That one usally will solve the puzzle.

It doesn't have to be the same villager if that helps. I got that puzzle with two.