Wow! Great job! Thanks so much. I'll let her know she should destroy it before it destroys her garden.

Lantana.

Okay! With this info, perhaps we can help. First, parsley is a fall and winter crop here in Mississippi. You plant it when the temps start to fall about late October, and it produces through the cold months, bolting in mid to late spring. I assume that chinese parsley would be the same, since very many chinese greens are also cold weather crops. By the way, this info goes for cilantro and sage too. Sweet alyssum is a cool weather flower. It is virtually impossible for me to grow here in Mississippi. The weather is way too hot for it between May and early November. And, it wont do well in the cool months either, because it won't take much frost. So, it rarely has enough time to grow and bloom before either a freeze gets it in late fall or the heat of summer gets it in spring. I grow Euphobia Diamond Frost instead. It has the same baby's breath kind of look and the hotter it gets, the better it blooms. (No fragrance, though.) There could be one or two reasons for your marigold problems. We have had a weird spring here. It warmed up nicely in mid March and seduced me into planting tomatoes, squash, and cucumbers. Then the nights promptly cooled back down into the forties and the plants didn't grow. They were so stunted, that I finally pulled them up and replanted in May. (lesson learned.) Marigolds are a hot weather flower and they hate cold soil, so if you planted them before the last week of April, this could be your trouble. On the other hand, since your shastas aren't doing well either, and if they and the marigolds are planted together, my next guess is poor drainage. You say your soil is soft and squishy when it's wet. About three days after a rain, is it still soft and squishy? Moldable, like Play Dough? I'm betting the answer is yes. Virtually the entire state of Mississippi has clay soil. What you want is clay loam. That's the goal, but as LAgal said, it's not a fast or easily realized goal. The answer is organic matter and lots of it. That term includes any and/or all: peat moss, chopped leaves, homemade compost, grass clippings, composted (not fresh) manures, and kitchen fruit and vegetable peels (not meat or dairy). If you want fast results, you need to pile a minimum of six inches, though a foot or more is better, of this material and till it in. Let the soil rest for a couple of weeks (for the material to break down) and then plant. Be sure to mulch well. But it's so gosh awful hot out there!.... So, if I were you, I would pot up the shastas and anything else you want to keep, cover the entire area with cardboard or 10 sheet thickness of newspring (not shiny or colored ink parts), overlap the edges so no light gets in, wet it down with a hose, and then pile on the organic material for the rest of the summer. You want 18 inches to 3 feet of stuff. By mid to late fall, you should be able to plant in it, though if you want, you can wait till spring. Just cover the pile with pinestraw mulch over the winter. You'll be amazed at the difference in your soil! Everybody thinks that gardening is about plants, and it is. But the way to have a beautiful garden, is to create top notch soil. There's no shortcuts or detours around it. Build your soil and your soil will give you gorgeous plants.

Thanks for the confirmation. I'm pretty convinced that's what we were sold. Noticed it is much easier to start from seed than a. tuberosa, which is apparently another clue it's tropical. Nice plant in spite of the sap hazard. We've never had reason trim them, so not much risk - but always good to be aware. One of our "anywhere, anyhow, anytime" plants is Zexmenia. A consistent, though not prolific, bloomer that continues to look good on only rain water once established. Can be used in sun or shade. Not the best photo, but shows lantana and salvia growing through its fairly dense cover.