Perennial Planting Guidelines
Herbaceous perennials differ from woody perennials when it comes to planting requirements. Here are some guidelines to follow when planting containerized herbaceous perennials.
- The plant crown should be even with, or slightly below, the surrounding soil. Herbaceous plants should not be planted high like woody plants are. There are a few exceptions where planting the crown more than slightly below the surrounding soil is advised. Peonies and Clematis are two examples.
- Loosen surrounding soil at least 3x the root ball width. More is better. If planting a group of plants, loosen the soil in the entire planting area. If the soil is not compacted, loosen the soil slightly deeper than the root ball depth. If the soil is compacted, loosen to below the compacted zone to ensure good drainage. Mix in a high quality compost.
- Container potting soil is not beneficial to the new transplant once in the ground. Remove the lower ¼ to ½ of the root ball if there is loose potting soil that can easily be removed without destroying the integrity of the root ball. If highly root bound, cut circling roots on two sides.
- Plant densely to discourage weeds. Ground covered by leaves prevents weed seeds from germinating by shading. More shaded ground means less weeds.
- Contour the final grade of the bed to keep water from running off the planting area.
- Mulch planting area with an organic mulch to conserve moisture, control weeds and feed the soil. Reapply as needed.
- Water heavily at planting and regularly until established.