Should I Put Worms in my Container Garden

Should I Put Worms in My Container Garden?

Container gardens are ideal for people who have limited room for a large garden or like the simplicity and ease of a self-contained environment.  While many people may be tempted to add earthworms to a container garden, adding worms is a bad idea. Not only are earthworms unnecessary, but a container garden is not a suitable habitat for earthworms to thrive.  

In the ground, earthworms work to aerate the clumpy soil and transport valuable nutrients to your plants. Usually, fresh potting soil is used for container gardens which is already light and airy. Plus, most potting soil mixes already contain additional vitamins and nutrients, making the addition of earthworms superfluous. If you find your container garden is lacking nutrients, try adding fertilizer, compost, or manure to help supplement your plants.

Do I Need Worms?

Earthworms add little benefit to a container garden.
Earthworms are not needed in a container garden.

When planting flowers and vegetables directly into the ground, the soil is hard-packed, tough, and rigid. Earthworms can help break the soil into smaller pieces, aerating the soil as they move in search of food. In the ground, worms are largely beneficial and help to increase drainage, keeping your pants’ roots healthy and happy.

However, in a container garden, the soil used is typically potting soil. This type of substrate is loosely packed, light, and fluffy. Plus, potting soil is usually packed full of valuable nutrients and fertilizer specifically designed for potted plants. In a container garden, worms are not needed because the quality of potting soil is already ideal for plants.  

Why Are Container Gardens Unsafe For Worms?

Adding worms to your container garden is unnecessary for the health of your plants and could jeopardize the overall health of the earthworms. Container gardens are very different from the natural soil found in the ground and often provide an unsuitable habitat to keep earthworms healthy. Container gardens are unsafe for worms because:

  • Temperature – Unlike the earth found in the ground, soil in container gardens is subject to a range of temperature swings. When the temperature changes too quickly, it can become inhabitable for worms. A hot summer day can cause the soil temperature to spike, killing the worms.
  • Moisture – While soil in the ground gets natural groundwater to keep the soil moist, container gardens largely rely on regular watering. The soil can dry out completely and quickly, which can be fatal for earthworms. Conversely, the soil in a container can become too flooded, especially after an intense rainstorm, which could drown earthworms trapped in the container.  
  • Nutrients – Because a container garden has a limited supply of nutrients, which are not regularly replaced, an earthworm will quickly run out of food. A container garden simply does not contain enough nutrients to support a healthy earthworm population.  

What If I Keep My Container Garden On the Ground?

One of the main challenges with keeping earthworms in a container garden is the limited amount of resources available to the worms. Putting a container directly on the ground, with large drainage holes at the bottom of the planter, may be a way to combat the challenges posed by container gardens.  

If the drainage holes are big enough for the worms to move through, it could potentially provide a suitable living environment for the worms. When the soil is too moist or dry or lacks the needed nutrition, worms could simply leave the container garden. However, with a less than appealing habitat, chances are limited that worms would return to the container garden once they have escaped through the drainage holes.  

How Can I Compensate Without Worms?

If you notice your container garden is suffering without the presence of worms, there are ways to compensate and help your container garden flourish. The best ways to counter the lack of worms in your garden include:

  • Fertilizer – Add fertilizer to your container garden to help give your plants targeted and beneficial nutrients. Fertilizer will help to revive and replenish the soil. 
  • Compost – Adding natural compost to your container garden will help to boost the soil’s nutrients. Compost can be mixed together with potting soil.  
  • Manure – Another natural option to help increase the quality of the soil in your container garden is to add manure. Mixing manure with your potting soil helps bring microorganisms to your container garden. These will help break down organic material faster, creating more available nutrients for your plants to absorb.  
  • DolomiteDolomite may be needed to balance the pH of the soil

Are Worms Harmful to Container Gardens?

Should I put Worms in my Container Garden?
Nuisance worms like caterpillars can eat plants.

Earthworms are not a harmful addition to a container garden, although they may not offer much benefit. There are, however, a handful of potentially dangerous worms that will move into container gardens. These worms can be detrimental to your plants. Some nuisance worms considered pests in container gardens include:

  • Grub Worms – Sometimes just called grubs, these worms are technically the larvae form of larger beetles. Grubs will eat the roots, stems, and leaves of just about any plant they can find. These insects grow slowly, so they will feed off your plants for an extended time.  
  • Cutworms – Another insect in larvae form, cutworms are butterflies and moths. Some people call cutworms caterpillars. These insects pose two dangers to your plants. First, the larvae will feed on the roots and stems of your plants. Secondly, after the caterpillar transforms into a butterfly, it will return to the same plants to lay new eggs, repeating the destructive cycle.
  • Nematodes – While some nematodes are hugely beneficial, feeding on bacteria that would otherwise harm plants, other nematodes will eat the plants. Parasitic plant nematodes will attack the plants in search of nutrition.  

How Can I Get Rid of Nuisance Worms?

Once nuisance worms like nematodes, caterpillars, and grubs have moved into your container garden, it can be difficult removing them. Generally, three forms of removal methods are recommended.  

  • Mechanical – Physically remove visible worms with your hands. This method may only be practical for worms you can see on the surface and won’t help with worms living deep in the soil. 
  • Biological – Some gardeners will introduce a different insect species known to feast on nuisance worms. Some options include ladybugs or mantis.  
  • Chemical – To chemically remove nuisance worms, some people prefer to use insecticides. Be sure to use insecticides safely, especially if you grow edible vegetables in your container garden.  

Final Thoughts

Container gardens are wonderful additions to any home, especially when they produce beautiful flowers or delicious vegetables. Because most people use potting soil that is loosely packed and full of nutrients, the addition of earthworms is not necessary. Not only will worms offer little benefit, but they could potentially die in the container garden because of inhabitable living conditions. Nuisance worms, like grubs and caterpillars, may take up residence in your container garden and should be removed to protect the overall health of your plants.