In addition to the veggies and herbs I'm growing, I've also got flowers in pots and planters on my front porch. My marigolds are filling out like crazy and buds are appearing. I was advised not to thin them out as they grow like weeds, which seems to be the case in these pots. The only issue with them is that I see some leaf borer activity. I'm currently looking for a spray that will kill the pests but not harm bees and beneficial insects. Neem oil is recommended by many. Pyrethrin is organic, but it appears it has to be applied very carefully to avoid hurting pollinators. Does anybody have any thoughts? My Shasta Daisies are finally coming along. My main question: do these need to be thinned out? I understand that these are larger plants, and the instructions seem to be that a lot this size should have no more than two or three. I've got two planters like this with Zinnias. They're largely thriving, and the larger plants have buds. However, one side of the pantry above has plants that have leaves that have wilted or dead light brown parts. I don't see any pests. What's going wrong here? The other end of the same planter has some of my strongest of these flowers, so I'm really confused. Also, do these need to be thinned out?

Finally, I've planted some marigolds in my back bed, but they're struggling. The ones from seed are stuck at about an inch tall and turning purple on the leaves. The full grown plants I transplanted are turning purple, too. What gives? (Sorry, no pictures of these right now.)

I appreciate any guidance.