A longtime favorite for spring gardens and landscapes, the peony is a hardy and easy-to-grow perennial. Best planted in a sunny spot with well-draining soil, your peony will give you an abundance of bright, vibrant blooms that, depending on the variety you have, will be in shades of deep rose, pink or white.
Unlike many plants, your peony does not require regular feeding or fertilizing. Depending on the type of soil in which you plant your peony, you can even skip fertilizing for a year and it will still produce blooms for you. In fact, overfertilizing will reduce flowering. But, to have an abundance of blossoms with vivid colors, apply a low nitrogen fertilizer (5-10-10, or 5-5-5) in the spring when the shoots of the peony are 3 to 4 inches tall. A low nitrogen formula will provide you with more blossoms and not an overabundance of foliage.
For dry fertilizer, spread it out from the plant crown, where the leaf drip line will be. Work the fertilizer lightly into the soil about 1 inch deep, then water the area thoroughly. Do not dig too deep into the soil when working the fertilizer in. Peony roots are not deep, and direct contact with the fertilizer will burn the tender roots. Again, underfertilizing is far better. Peonies love potash. Work 2 cups of bone meal, or two to three handfuls of ash from your fireplace, into the soil surrounding your peony in early spring. Rose fertilizer also works well for peony feeding. If you have loose, porous soil where nutrients are lost and washed away from watering and rain, you can apply another, light feeding at the end of summer or early fall to feed your peony over the winter.
The first year you plant your peony, you should not feed it any fertilizer but allow it to become established. Your peony will be much hardier and capable of utilizing any fertilizer you feed it much better after the first year in your yard.