Wick Watering for Container Plants

From the simple to the extravagant, the garden marketplace is full of products that can feed and water your container plants for you. But if you prefer to spend your money on plants, rather than "systems," you may want to consider a simple and inexpensive method using wicks. If you're leaving home on vacation for a week or two, or you simply don't have the time to water dozens of containers every day, wick watering can be an efficient, do-it-yourself solution to keeping your container plants happy.

How It Works

The theory behind wick watering is a simple one. A wick is run from the top of the pot down through a drainage hole and into a reservoir holding water. As soil in the pot dries out, capillary action from the wick draws water in from the reservoir and re-hydrates the plants. When the soil reaches it's moisture bearing capacity, the wick stops drawing water.

Method #1 (For Multiple Containers)

Materials:

• Wicking cord
• 5 gallon bucket (reservoir) or several plastic milk jugs

The best way to insert water wicks into your container plants is to "plant" the wick in the pot at the same time you're planting the container. The wick(s) should be long enough to reach from your water reservoir to the bottom of the pots. Excess cord can be coiled around the sides of the pot and hidden beneath the plant's foliage when you're not using it.

When calculating the length of the wicking material, keep in mind that the reservoir should be elevated slightly above your pots (a block or stool works well). If your pots are already planted, just use a pencil or screwdriver to gently insert the wicking material down into the potting soil--disturbing the plant's roots as little as possible.

Arrange your pots closely around the water reservoir. Make sure your plants are watered normally (from the top) before starting the process. As the soil dries, water will be drawn into the pots through the wick.

Method #2 (The African Violet Method)

Materials:

• Wicking cord
• Water reservoir that fits underneath pot.

A tray with a hole in the center, that allows the pot to rest of top of the reservoir.

This method works well for small, individual pots. It is commonly used to water small African violets. A shorter cord is placed in the bottom few inches of the container and run out the drainage hole. The pot is then set on top of a reservoir and the cord is allowed to dangle into the water and draw up the water as needed. If needed, fertilizer can also be added to the reservoir. This method works best for smaller plants because water will only travel about 4" up the wick.

Testing for Success

Don't set off on your summer vacation before testing out the bugs in your wick watering system. Wicks can fail for several reasons:

• The soil in the pot is too moist or too dry to draw in water.
• A wick is too small in diameter to draw up enough water for a large plant.
• There are not enough wicks in the pot.
• The soil is too heavy or too compact.
• The pot is sitting on top of the wick and the wick is getting pinched.

Most gardeners find this system reliable for a week or more, but if you're leaving town, perform a trial run for at least as long as you're going to be gone.

When to Change the Wick

Over time, wicking material will slowly get clogged with soil particles, algae, minerals, or fertilizer salts. Expect to change them every 6-8 months, which is also a good time to freshen up the soil in your containers.

Wick Watering Tips:

• Plastic or ceramic pots are recommended for wick watering. Terra-cotta and wooden planters tend to lose moisture through the sides of the pot and will wick water away from your plants.
• The right soil mix is important for wick watering. Soilless mixes or light "potting soils" work best. If using a regular soil, it should contain at least 50% vermiculite or perlite.
• A thirsty plant in a 6" pot can drink up to a quart of water per day. Bigger pots and plants with large root systems will need more than one wick per pot. Just how many depends partly on much water the soil will hold. A 3" pot will only need one wick. A 6" pot may need two, etc. Experiment.
• Nylon parachute cord works well ( 7/32"-3/8" diameter ) to make wicks. This is readily available at big box home centers, hardware stores, or outdoor stores. Acrylic, nylon, or polyester materials work best, because unlike natural fibers such as cotton, they don't rot or promote fungi growth. Wicks designed especially for this method are also available at many garden supply stores.