I know this plant is invasive, but it is not illegal to plant it in NYS. It is such a beautiful ground cover. I would like to plant it under my peonies to keep weeds down. Would it be harmful to the peonies?
I don't necessarily think it will threaten your peony but without suitable measures taken, this plant could get out of control. I would ensure that it stayed within its bounds by implementing some type of edging and installing it a few inches in the ground. You could also place landscaping fabric or newspaper down around your peony plants and add mulch to keep the weeds down and then simply place containers of the celandine around it for looks.
I have plenty of Celandine plants in my garden. They bloom from May to September ?. However, because we have had to take down several trees, they are getting too much sun now and getting brown. Nonetheless, they keep growing new fresh stems/leaves under the "sunburnt" ones. 1) when is a good time to move them in shadier location? 2) most importantly: can I trim off the sunburnt parts or is this going to exhaust the plant or otherwise compromise next year's blooms? Answers and advice most appreciated:)
Yes, you can trim away any dead material. You can move them really any time, but I would wait till a cooler period in the weather. Then make sure they receive water after transplanting.