for the last 3 years, peony bush develops brown spots on leaves and buds. The buds do not bloom.
Your peony may have a fungal disease, botrytis blight (gray mold) or leaf blotch. Here's an article that tells you how to deal with it:
https://www.gardeningknowhow.com/ornamental/flowers/peony/controlling-peony-measles.htm
th 0-10-10. This is 3rd year it fails to get flowers from the buds.
These articles will address the issues at hand:
https://www.gardeningknowhow.com/ornamental/flowers/peony/why-your-peony-buds-but-never-flowers.htm
https://www.gardeningknowhow.com/ornamental/flowers/peony/peony-care.htm
Though your tap may be salty... Rainwater is not. If you water with rain water, you can avoid any issues with less than ideal tap water.
Here is an article that will help you with the care of the plant:
https://www.gardeningknowhow.com/ornamental/flowers/peony/peony-care.htm
I have peonies that die back to ground level each year and two tree peonies also...We will be moving to a new home next year and wish to take them with us...Is this going to work?? I also want to divide them so my daughter can have a start from each of them...
Herbaceous peonies, those that die back in winter, resent being moved but it can be done. They may not flower for several seasons, however. Tree peonies, once established, should not be transplanted.
Here is more information. Hope it helps!
https://www.gardeningknowhow.com/ornamental/flowers/peony/how-to-grow-a-tree-peony.htm
https://www.gardeningknowhow.com/ornamental/flowers/peony/dividing-peony-plants.htm
I have just purchased a container peony at a nursery and have a couple questions. It is in a pot approximately 8 inches in diameter and 7.5 inches in height. The plane is approximately 18 inches in height. Will this peony be ok in its present container through the rest of the year and be transplanted next spring? Or should it be transplanted this fall before winter?
That will have plenty of room in the container. It would be best to, only, transplant once.
Here is an article to help you care for the plant:
https://www.gardeningknowhow.com/ornamental/flowers/peony/peony-care.htm
A couple established bushes start to grow, then suddenly the bud and upper stem turns black and dies. This is the second year that it has happened. The second problem is affecting a couple of bushes that I have had at least 18 years. This year, most of the bushes grow about half the normal height and only a small portion grew to its full size. The first picture I attached shows the black buds and stems. The other show the two heights of my older bushes. This year, we have had a tremendous amount of rain. So much that the soil does not dry out between storms. Does this have anything to do with it?
Are the plants in more shade than they used to be? I can see in the photo the peony is in shade but the irises are in sun. Peonies need full sun to thrive.
Bud blast causes the black buds and stems and is usually a cultural issue. I've included a link to a care article below. Because of the rain, you may have fungal issues such as root rot going on that is causing the plants to stop growing. Plants normally can't be saved from root rot.
https://www.gardeningknowhow.com/ornamental/flowers/peony/peony-care.htm
https://www.gardeningknowhow.com/ornamental/flowers/peony/peony-bud-blast.htm
https://www.gardeningknowhow.com/ornamental/flowers/peony/how-much-to-water-peonies.htm
Not easily. This requires very precise conditions to perform tissue cultures. This is something that I don't recommend anyone that does not have quite a bit of laboratory experience to take on.
This article will explain agar use for plants:
https://www.gardeningknowhow.com/garden-how-to/propagation/seeds/agar-growing-medium.htm
This document from Michigan State University will give you a decent run-down of performing a tissue culture:
https://www.gardeningknowhow.com/garden-how-to/propagation/seeds/agar-growing-medium.htm