How to Refresh Soil in a Container Garden. If you grow vegetables, perennial and annual flowers or shrubs in containers, you absolutely do not need to replace the soil in every pot each year. Instead, you can save money and resources by refreshing the soil each spring. Refreshing the soil each spring is a quick, easy and inexpensive process-and it will help your container gardens look lush year after year. Here's what you need to do.
How to Refresh Soil With Perennial Flowers or Shrubs
If you have containers planted with shrubs or perennial flowers, you can refresh the soil without taking apart the entire pot. If the soil has been in the pot for more than a few months, a crust of larger soil particles, pieces of bark and vermiculite or perlite often forms near the top. Start by scraping this crusty layer off, plus another inch or two of soil beneath it.
Sprinkle granulated fertilizer evenly over the soil surface and scratch it in with your trowel (follow the application recommendations on the fertilizer's package).
Top off the pot with a layer of compost, making sure that you end up with the same level of soil that you started with.
How to Refresh Soil With Annual Flowers or Vegetables
Water your pots a few hours before you plan to refresh the soil, because damp soil is easier to break apart than dry soil. Meanwhile, spread a tarp out on a flat surface, like a driveway or patio, or if your pots are light enough to lift, you can also work on a table.
Dump the potting soil inside the containers out onto a tarp. Break it apart with your trowel and remove any dead plants, including their roots. Then, mix in some compost so that the potting soil/compost mixture is approximately 3/4 potting soil and 1/4 compost. Finish up by stirring in some granulated organic fertilizer (follow the application recommendations on the fertilizer's package).
Refill your pots with the refreshed soil. You do not need to put gravel or pottery shards in the bottom of your pots. This practice actually impedes drainage, makes containers heavier and is completely unnecessary. The most important thing for drainage is ensuring that your containers have one or more drainage holes. You can place a coffee filter over the drainage holes if you want to prevent soil running out of the holes the first few times you water.