Six tips for watering container gardens

Every garden needs water, but with a container garden’s limited soil volume, proper watering is crucial for plants to stay productive.
“Proper drainage is just as important as the amount of water added to the container,” says Andrew Holsinger, University of Illinois Extension horticulture educator.
Soil type matters: Avoid using garden soil for containers. Like building a healthy soil in a garden, the balance of the components of your potting media will affect drainage. A good balance of organic matter can provide nutrients and added pore spaces to retain water. Vermiculite or perlite are commonly added to help with drainage. If reusing a container, disinfect it before planting.
Pick the right container: A variety of containers are suitable for growing vegetables and herbs. Choose your container based on what you plan on growing. Some plants such as tomatoes need more soil to accommodate the root system. Always chose a container with drainage holes in the bottom. Multiple holes are also better than a single hole.
Container materials: Non-porous and porous containers will affect the soil’s moisture level. Potting mix in clay, fabric, and unglazed ceramic containers will dry faster than plastic or glazed pots.
When to water? Check your containers daily. Most plants need to be watered when half of the moisture is gone. Use a soil moisture probe or estimate by the feel of the soil. The container will also become lighter as it dries out. Water thoroughly until the water drains out of the bottom.
Automatic watering: Self-watering containers can supply a reservoir of water to lessen the frequency of watering. Drip irrigation for containerized plants offers the ability to supply just the right amount of water at the right time.
Prevent water loss: Limit how much you need to water, by mulching the top of a container. “Mulch is an effective tool for reducing evaporation, even in container plantings,” Holsinger says.
For more information about growing vegetables and herbs in containers, visit the University of Illinois Extension successful container gardens website at go.illinois.edu/containergardening.
University of Illinois Extension develops educational programs, extends knowledge, and builds partnerships to support people, communities, and their environments as part of the state’s land-grant institution. Extension serves as the leading public outreach effort for University of Illinois Urbana-Champaign and the College of Agricultural, Consumer and Environmental Sciences in all 102 Illinois counties through a network of 27 multi-county units and over 500 staff statewide. Extension’s mission is responsive to eight strategic priorities — community, economy, environment, food and agriculture, health, partnerships, technology and discovery, and workforce excellence — that are served through five program areas — 4-H youth development, agriculture and agribusiness, community and economic development, health and community wellness, and natural resources, environment, and energy. Learn more at extension.illinois.edu.