With Snapshot 2.5 TG being a pre-emergent that will prevent germination, you will want to wait atleast 4 to 6 months after the application of Snapshot 2.5 TG for planting any seeds, flowers, bushes, shrubs, etc.
I would recommend calling the Cooperative Extension in your area and speak to the master gardener to get the plant identified. I would definitely be happy to recommend something for you when you have the weed identified.
http://www.csrees.usda.gov/Extension/
Please refer to the Snapshot product label for a full list of tolerable plants. If you need anything else, please let us know.
Snapshot 2.5 TG - 50 lb. bag Can be used in Peonie beds. It will only prevent seeds of listed weeds from germinating or multiplying.
If you just want to place containerized plants on top of an area treated with Snapshot 2.5 TG, then we would recommend waiting until the application has been watered in and the area is dry. If there is a lot of movement while the application is wet, then you may disrupt the barrier and get inconsistent treatment from the Snapshot application.
Snapshot 2.5 TG - 50 lbs. does not kill any weeds. It will only prevent seeds from germinating but it does not list skeletonweed on the label as a controlled weed. We do apologize but we are not able to find a product that is labeled for it and would work. We did find this article here that might help.
Snapshot is a great product and listed for many tolerable species and targeted weeds. We would only recommend applying near the ones listed on the product label. We cannot comment on the safety around a different plant, flower or tree variety that is not listed.
Snapshot 2.5 TG - 50 lbs. can be reapplied 60 days after initial application.
Snapshot is not known to be volatile and should not harm the other plants as long as they do not share the same soil.
Snapshot can be applied to beech grass for preventing listed weeds to emerge.