I have a couple of ideas, but first....do you know what kind of parsley you planted? It looks more like an Italian flatleaf type or maybe even Hamsburg, but beyond the fact that it may be a less-common type, it also has something wrong with it. Knowing what type it is might help us figure that out.

Also, do you use any sort of herbicide on your property at all, and have you seen any aphids or other pests on it?

I forgot to ask the most important question, and one or two less important ones.

Are you POSITIVE it is parsley: does it smell like parsley and taste like parsley? Also is this a first-year plant or a second-year plant?

It's flat leaf and it looked normal when I planted it. And it does taste and smell normal. It's in an herb garden surrounded by other herbs that are doing just fine so I don't know what would effect only that plant. Also, no pests on the parsley. I have something munching on the sage.

With flat-leaf parsley, as it matures, often the lower leaves do get sort of thick and large like that, but your leaves still have something else going on. The puckered and twisted appearance of the leaves is the symptom, and it is not always easy to figure out what has caused parsley leaves to look like that because there are several possibilities.

1) If you have had aphids or something similar on the undersides of the leaves, they could have caused the damage that left the leaves looking like that.

2) Aphids and some other insects help spread viral diseases that affect parsley. Your plants also can contract the viral diseases in other ways. The viral diseases don't necessarily kill the plants, but can cause foliage to have a distorted appearance like you're seeing on the leaves. No cure for the virus, and I generally just ignore a non-lethal plant virus if one pops up on something in my garden. Most previously healthy plants can outlast the virus and continue producing a harvest.

3) Herbicide damage. We have a major issue in this country with herbicides damaging plants. There are several ways it happens. One way is that someone within, let's say, a half-mile of you, sprays a herbicide on a lawn or whatever and some of it vaporizes and moves through the air, damaging whatever plants it hits. Often, when plants are hit by pesticide drift, it isn't a heavy enough concentration to kill the plants, but it can cause discolored foliage, stunted growth, and twisted, puckered, curled or distorted foliage. Another way is that a gardener inadvertently adds something to their soil that contains certain herbicide residues that are long-lived in soil, manure, compost, mulch, etc. Google "killer compost" to read more about this. Finally, sometimes it is a simple as a gardener or their non-gardening spouse (or their lawn service) using a weed-and-feed product on the lawn near the garden without thinking about the fact that the weed component of that weed-n-feed product can damage or kill broadleaved plants in the adjacent garden.

Your parsley should be fine even if it looks a little odd.

If you are seeing insects that you think are vectoring disease, you could treat with the insecticide of your choice, whether synthetic or organic in nature, following label directions, but I think the plants will be fine without treatment unless the insect situation worsens. Even though the distorted foliage looks peculiar, it isn't harmful to the plant or to you.

By the way, since only the parsley is affected, I think it is most likely a parsley virus. A parsley virus would affect only other plants that are in the parsley family, but it wouldn't necessarily affect all plants in the parsley family. Some plants just have better resistance to disease than others, just like some people have better immune systems than other people do.

Dawn