Container-grown plants can be planted at any time. If your bud union and roots aren't aligning this way, your pot is too large or small. I prefer planting bare root peonies because they are less expensive than container grown plants and by planting them in the fall they will have time to develop a strong root system, ready for robust growth next spring. How to Grow a Peony in a Pot. Peonies prefer heavier soils (but not waterlogged), in a sunny or lightly shaded position. Mix plenty of organic matter into the planting … This way they won’t need to compete with other plants and it will be easier for you to control light and moisture. Peonies are hardy plants from zones 3 to 8. Bare root planting season is pretty short, and if you're not on the ball it can slip right by you. Dig a shallow hole no more than 5cm deep and firm the base of the hole. Now the term bare root means that all the soil was removed from around the tuber when the plant was dug from the field. While we are talking about peonies let’s dispel another myth: that peonies don’t like being moved. Position rhizomes with buds facing upward, backfill and lightly firm soil, then water thoroughly. However, they perform at their best in regions that get 500-1000 "chill hours" per winter, temperatures between 35-45 degrees. If you want to give your new perennials a little extra TLC, you can get them started in pots. • Herbaceous peonies are sold as bare root rhizomes with a few buds or ‘eyes’ and are best planted in autumn. Most plants need to be shipped and planted while still dormant and before their buds start swelling. Planting Bare Root Perennials in Nursery Pots. Subject to rule number 1 (above), carefully lift the plants in the autumn and replant or divide them (remember to keep 3-5 buds on each bit of root that you divide and if you are planting them in a container, don’t overwater them). Ensure that the bud union is level with the rim of the pot: The roots of a bare rooted rose plant will be pruned so that their roots are half the distance of the container when the bud union sits at the rim of the pot. Place the bare rooted rose bush into the pot. Ideally, plant bare-root peonies while the soil is still warm in the autumn, or as it warms up in the spring.