About a month ago I dug out of the garden and potted up some Lunaria...
About a month ago I dug out of the garden and potted up some Lunaria ‘Rosemary Verey’ (money plant) seedlings. They have grown and were doing well, until today when several of them are suddenly wilted! There is a photo of the flat, and another of an apparently healthy plant with a wilted one. This seems to be the same thing that happened to 3 boxes of bare root echinacea (coneflower) that I bought at Sam’s Club in March. I potted them up and all seemed to be going well until individual leaves—not whole plants, at first—started to wilt. This started when they were still inside under lights. They were not overwatered. It progressed until, out of about 20 plants, I have one left. Can you tell me what is going on? This is driving me nuts.
This looks like lack of establishment. Wilting is a symptom of poor roots such as overwatering. What type of soil did you use when repotting? If it was a heavy potting soil or garden soil, this can causes poor root growth conditions and the plants decline. The soil is too dense.
For young plants they need heat, good light, and a soilless potting mix. (seed starting mix - peat moss, perlite, and vermiculite).
Here is more information on seedling care http://extension.umd.edu/hgic/topics/seedling-care
I think it must be something else. I used a bag of Miracle Gro potting mix, and the plants have put on substantial growth since they were potted. They were very small seedlings when they were dug. Also, why would only some of the plants wilt? Could this be a disease?
Since you transferred the seedlings from your garden to the containers inside it is possible you may have transferred some fungi when you repotted.
Also, If your containers are saturated with water, the roots will stop growing and pathogenic fungi that like wet soil can infect your plants. The damping off organisms Pythium, Phytophthora, and Rhizoctonia, can quickly kill a container of seedlings if the growing media is kept too wet. See more http://extension.umd.edu/hgic/topics/wilt-fall-over-or-cut-soil-line-vegetable-seedlings-and-transpl...
Knock several of the plants out of the pot and look at the roots. They should be firm and white. Pull on the roots. If the outer part of the root comes off in your hand then they are infected. If brown, then the roots are dead.
Also, the foliage looks like it has some leaf spots and we cannot say why. This is usually an issue if plants are in a humid environment. There is no cure for the root rots or the leaf spot. If you have any plants left that are not affected, you can plant them. If you have any seeds left from last year, you can plant seeds.
Here are some factors to consider for the next time you plant. If an infection occurs, dispose of the plants and growing medium, wash containers and tools to remove any debris, and soak them for 10-15 minutes in a solution of 1 part chlorine bleach to 10 parts water. Then rinse with clean water.
Use a soilless seed starting mix as some of the potting mixes may contain compost. Wait until the top of the growing media is dry before watering.
Take a look at our website and videos on seed starting and seedling care.