How does my garden grow?

[sanzfrancisco]

Not particularly great, evidently.
I wanted to see if I could grow some dahlias, so I purchased six clusters. Two of the plants are coming up fine, (no flowers yet,) three are being snacked on by snails or slugs, and then there's this one. She started out very well, and is getting ready to bloom. However, a problem has presented itself.
Can someone tell me what this is?
Thanks,
janice

 

[seby0044]

I prefer to use grow tents to grow my plants. It seems to be a much more efficient solution.

 

[sanzfrancisco]

Thanks for the reply, but water droplets burned the leaves from being being in the sun.

 

[Marck]

The leaf damage in the photo is caused by Microlepidoptera larvae called leafminers. Basically the caterpillars of very small moths mine through the interior layers of the leaf as they feed. This damage is unsightly but usually does not severely affect the vigor of the plant unless severe.

 

[sanzfrancisco]

Thanks very much. I appreciate your response.