I have lots of questions for you:

Where do you live? It's very helpful to include the state in your "Posted By" link.

What kind of soil and what kind of soil prep did you do before you planted? Clay? Sand? Did you till, amend, double dig, etc.? Or did you dig holes in your lawn and plant?

Where are these plants? Sun? Shade?

When did you plant? March? May?

The answers to these questions will give us clues as to your trouble. Without them, we can only shrug.

Thanks Donna. Here is my question again with more details.

I live in Oxford MS, zone 7.

One patch is in front of the house where the previous owner had some scattering wood mulch but didn't plant anything. It had weed fabric underneath, which I tried to pull out when digging before planting the seeldings. The soil is clayish, hard as stone when dry, and soft and squishy when soaked. I added some top soil and humus and manure before putting down the seeldings. In the patch a few gardenias and a magnolia tree (it's outgrowing the corner now) are doing quite well.

Another patch was dug out from the lawn. It grows tomatoes and beans but the bok choy seedlings stay with two baby leaves and finally disappear after rain and worms.

Both patches have good sunlight - at latest from 10am on. They are planted early to mid April.

Any advice is greatly appreciated!

anfun, donna is always helpful, so stay tuned. I'm in Lee county so near you. i am not having a good year for veggies, i think too much rain??? or maybe even too much sun, as i put my tomatoes in a new raised bed this year but last few years was a more shady location which i guess gave some relief from 'full' sun. but this is not about me. i'm reading between the lines and sounds like possibly you have not been gardening there very long. it takes time to really improve this clay soil. i'm here 4.5 yrs now and my beds are all pretty lush now. except the veggies this year. continue to improve your soil by adding organic matter. i compost and use that too. i mulch with shredded leaves that i collect in fall, my favorite mulch. i also use pine straw which is available in spring. or rake it if you have pine trees nearby. bottom line, things will improve. and there will be good years and not so good years for the entire garden or just for certain plants.
laurie

Thanks Laurie. I had some potting experience in my school days and my plants used to all die :(. Now that we have our house the garden is just calling for me. At least the previous owner left some established plants to keep my hopes up. The gardenias are blooming like crazy now!

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.

Wow, donna, that's some great advice! I've got some work to do :) At least I know what to do now. Thank you so much! Indeed gardening is not for the impatient.

Oh one more thing, I guess I need to remove a feet or two of existing poor soil before piling on 18 inches to 3 feet of organic material right? Otherwise the bed will be too high ...

Here's my true story. Several years ago, we owned a home that had been built after the top of a hill had been removed for fill. The house sat right on top of the hard pan layer. Needless to say, I wanted a garden. We rented a monster tiller one Saturday and my poor husband labored with that thing all day long in the heat and it did not penetrate more than 2 inches. Literally. We gave up and took the tiller back. I subscribed to Organic Gardening Magazine back then (now defunct) and I read about sheet composting in it (now called lasagna gardening. It's basically what I wrote above.). I tried it with the cardbaord and the organic material in the fall of that year. It made quite a mound on top of the area. By the next spring it had all composted and settled down to no more than one or two inches above the original grade. I went out there with a shovel and stepped on it. It went all the way down to the handle with virtually no effort! Miraculous! When we left that house ten years later, that bed still had the best soil on the property. Try it. You'll like it! :)

I live in Dallas, where it is also hot. And I hate to garden in the heat, so I use an even easier way: straw bales.

They're 4' long x 2' wide and tall, so I lay them side-by-side wherever I am going to put in a new row, with 18-24" walking paths on either side (which don't need improved soil). That automatically gives me a 4' wide bed, which is perfect for weeding or harvesting from both sides. Heavily fertilize the top of the bales to provide nitrogen, then water them enough so that there's no run-off, but enough for them to stay wet (they normally need a fairly heavy watering the first time or two, then just a quick watering once or twice a week if it doesn't rain). In 6 months or so, you can roll them to the side and start planting. You don't even have to use any cardboard or paper! Only the outside of the bale will still have much structure (where it stayed dry), so I normally break that up and use it for mulch. I discovered this method one spring, after I failed to move my Halloween display! That is as easy as it gets, I think!

Felis, yours sounds like a great idea. What do you use to fertilize with nitrogen, and why is it important?

In the mean time, let me report what had happened in my garden patch since I went off with Donna's method. I did exactly as described by Donna, put down card board, piled on leaves and twigs, grass clippings, etc. to a pretty high mound. Everyday I also insert my scrap vegetables and fruits under the mound, and a couple of times I got a large bag of vegetable scrap from the restaurants. After two months of rain and sun and wind, the mound has flattened some, and at the spots where I added "wet" vegetables, the mound sank more. I remember reading about "greens" and "browns" when composting, so the vegetables are greens, and dry leaves and woody stuff are browns. They need to both be present for the pile to decompose efficiently.

Now a funny thing happened. Some seedlings emerged from the mound and before I know it, they have covered half the patch. Turned out they are watermelons plants from the seeds I dumped into the pile. Since they landed on such rich soil (below the surface there is already nice black/brown compost), they are growing like crazy. The seeds started in late July. I'm curious to see whether they will find enough time to grow a few watermelons for me :)

I have also started to move the plants in the pots to their new home. Can't wait till next year to see the outcome of all this fun (and hard) work!