Planted containers of trees, shrubs, perennials, or combination plantings need occasional maintenance to keep them looking their best. Soil particles decompose over time, causing compaction and making it harder to absorb water. Depending on the size and shape of your container and the types of plants used, most containers should be refreshed every two to five years or once the soil level has dropped several inches. The ideal time for this maintenance is late winter or early spring.
There are several components of this project:
- Removing the plant(s) from the container
- Removal of old soil
- Light trimming of roots and pruning of plants for health and desired shape
- Cleaning/inspection of container for cracks (reseal if winter cracking is a concern)
- Adding fresh potting soil
- Repositioning plants, editing/adding to plant combination, more fresh soil
- Fertilizing with slow-release, organic nutrients
- Mulching or top-dressing, if desired
Spread out a tarp, drop-cloth, or old shower curtain on the ground. If working with a very large pot, carefully lay the container on its side with a towel or cardboard to protect it, loosen root ball from sides of pot with hori hori knife, spade, or other tool, and tip pot or pull gently on a strong, woody part to remove plants; use a trowel to coax out the root ball if it doesn’t come out easily.
Remove Old Soil
Set the plants aside in the shade and continue to empty all or most of the old soil from bottom of pot. Check for obstructions to the drain hole; make sure pot can drain.
Prune Plants & Lightly Trim Roots
The plants that you have removed will have some old potting soil still stuck around their roots. Massage the root ball to loosen and allow as much soil to fall away as does naturally. Inspect the root ball for healthy color and size; if root-bound, score or trim roots to allow them to spread and remove old, damaged, slimy, or discolored roots. Trim plant to desired shape and size. If container has a combination of plants, separate each plant to inspect them individually.
Clean & Inspect Container for Cracks
Apply a liquid pot sealer to avoid freezing and cracking or clean container with 1:9 bleach to water solution if you are concerned about past pest or disease problems.
Add Fresh Potting Soil
If the pot is tall and doesn’t need to be counterweighted at the bottom, you may want to add a small amount of filler to the container before adding soil; only do this if planting annuals or using the container for a single season. Always use high-quality potting soil such as G&B Potting Soil or Malibu Baby Bu’s Potting Soil.
Reposition Plants & Add More Soil
Replace plants on top of fresh soil after mixing in an appropriate amount of fertilizer; press them firmly into the container. Continue to add more potting soil around the plants using light pressure to push out any air pockets. Be sure to cover all roots and to position plants at their original soil level. Always water well after planting and follow up with water and fertilizer as needed.