Watering Potted Plants
Container grown plants dry out quickly and require more water than their backyard counterparts growing in open soil. This is because potting soil is often lighter and less compact than regular garden soil and the water holding capacity around the plant is determined by the size of the container. Watering potted plants once a day or even twice daily may be necessary, especially if the weather turns hot and windy or your containers are in full sunlight. Watch closely, and check moisture levels often. If the growing media appears pale or cracked, or feels dry below the soil’s surface, it’s time to water.
The easiest way to water container plants is with a watering can or gentle hose. However, when you water make sure that you are watering the soil and not just the plant’s leaves. Continue watering until it runs out the drainage holes in the bottom of the pot. The idea is to water thoroughly but allow enough time between waterings for the soil to begin drying out. A moisture meter, available at many garden centers, can be used to instantly determine when to water your plants. If the potting mix remains soggy for too long, air will be forced away from the roots and your plants may suffocate or drown.
Do not let plants sit in standing water. If a saucer is used under the container, make sure that it does not remain wet for more than an hour or two after watering. Poor drainage and damp soil conditions favor root-killing disease fungi that can develop as either root rot or dieback. Visit the Ohio State University Extension for more information about root problems on plants.
Are your potted plants drying out too quickly? Try grouping them together so they shade each other. This will reduce water evaporation and decrease the need to water so often. It will also cool the soil and help keep heat stress to a minimum. In general, smaller containers will dry out more quickly than larger ones – but the bigger the pot, the more water it will require with each watering.
Tip: Use organic mulches on top of your soil mix to reduce moisture loss during hot summer days.
If you find yourself watering potted plants far more often than you would like, or you will be away for extended periods, consider installing an automated irrigation system. Many are commercially available or you can make your own pop bottle drip irrigation system here.
Another way to reduce the watering needs of container plants is to mix water holding “agro-polymers” (sold under the trade name Soil Moist) into the potting mix prior to planting. These super absorbent beads capture water that would normally pass by root zones. As the potting mix dries, the stored moisture is released back to the plants as needed.