Question? Issue with harvesting wild plants?

I just decided to start up a new game and I'm trying to get my gardening going better and make more money. I can't buy the good seeds yet so I'm trying to harvest wild plants and trees. But I'm having a problem and I'm trying different things to see what's going on. The issue is that the wild plant is rarely havestable, sometimes I visit a family on a lot that has good harvestable wild plants growing outdoors nearby. So, I will stay there talking with them and allowing time to pass and the plants you can see have harvestables on them, sometimes even glowing that greenish color meaning they can evolve. I go to harvest, and it will not let me harvest the plant, I can either view or uproot. But sometimes and I can harvest a plant even of that same type(snapdragon) but very rarely. I've been in the same general area without traveling for maybe 7 sim hours and still can't harvest. I would suggest that maybe a garden skill of 4 is not high enough but there was an occasion or two where i did harvest a good wild plant. So, am I missing something? I looked at Carls sims guides, and some other places and didn't really find an answer that suited my exact situation. Basically, one video said stay on a lot for a long-time fishing or something then the plant will develop, and you can harvest. Well, I've basically done that. I even visited the same area two days in a row thinking maybe it takes a whole day in a half for the plant to become harvestable. Some plants like a lily I didn't even see it develop any, while other plants in same area did develop but yet still unharvastable. Is there a trick to this I'm not understanding? and lastly I tried viewing the plant and then returning back to that plant later thinking maybe viewing it would trigger something but nothing.