Taking care of container-grown flowers and vegetables is similar to caring for plants grown in beds. But plants grown in pots do require extra watering and feeding. Here are some pointers for taking care of the plants in your container garden:
Water frequently: Because potting soil dries out faster than regular garden soil, container-grown plants need frequent watering (unless you're using self-watering containers). In really hot weather, you may have to water more than once a day, especially if the plants are large and roots fill the pots. If you let your vegetables go dry just once, you may spoil your harvest, causing conditions such as blossom-end rot on tomatoes.
Here are a couple ways to check whether your container is dry:
Stick your finger in the soil: If the top few inches are bone dry, you should water.
Lift or tip the container on its side: If the soil is dry, the container will be very light.
Water thoroughly: Wetting dry potting soil can be tricky. Sometimes, the root ball of the plant (or plants) shrinks a bit and pulls away from the side of the pot as the soil dries so that when you water, all the water rushes down the space on the side of the pot without wetting the soil. To overcome this problem, make sure you fill to the top of the pot with water more than once so the root ball can absorb the water and expand. In fact, you should always water this way to make sure the root ball is thoroughly wet. It's important, however, to avoid overwatering the soil; do the finger check before watering.
If you still have problems wetting the root ball, place your pot in a saucer and fill the saucer repeatedly with water. The water soaks up into the root ball and slowly wets all the soil.
If you have a lot of pots, you may want to hook a drip irrigation system to an automatic timer to water them; nurseries and garden centers sell special drip emitters designed for pots.
Fertilize frequently: Because nutrients are leached from the soil when you frequently water container flowers and vegetables, you need to fertilize your plants at least every two weeks. Liquid or water-soluble fertilizers (you just add them to water) are easiest to use and get nutrients down to the roots of your plants. A complete fertilizer that's organic is best.
Watch for pests: Worried about insects and diseases harming your container plants? Don't be too concerned. In general, container-grown plants have fewer pest problems because they're isolated from other plants. Insects aren't waiting on nearby weeds to jump on your plants, and sterilized potting soil doesn't have any disease spores.
Even though container vegetables tend to have fewer pest problems, you should quickly deal with any problems that arise so your whole crop isn't wiped out.
Because container vegetables are often located on patios or decks that are close to the house, special care should be used in spraying them for pests. Although container vegetables don't get as many pests as in the garden, you may have to spray occasionally; so, if possible, move the containers away from the doors and windows when you spray.