How to water outdoor containers

Containers are a great way to grow vegetables or annual flowers outdoors, especially on a balcony, patio or deck.

Any container must have at least one drainage hole - and no gravel in the bottom of the pot, which actually impedes drainage. The best soil for containers is a soil-less medium made up of peat or coir, with a smal percentage of perlite and/or vermiculite. Garden soil is not recommended because it tends to compact. For more information about growing in containers see: Vegetable container gardening

Use your good judgement when watering your outdoor containers with these tips: 

• Small containers need to be watered more often than large containers.
• Plastic and glazed ceramic containers tend to hold moisture longer than porous clay or terracotta containers which dry out much more quickly.
• Weather is a factor too: windy conditions and hot, dry weather means watering more often, sometimes twice a day. You may not need to water as often when the weather is overcast and cool.
• Check your plants often during a hot spell for signs of wilting or flagging. Water as often as needed.
• The best time of day to water is in the morning. In this way, plant roots will have access to moisture during the heat of the day. 
• A layer of mulch on top of the soil in your containers prevents water loss through evaporation.
• Know the needs of your plants. Plants like succulents need the soil to dry out in between watering. Vegetables, in particular, tomatoes, peppers and cucumbers need to be evenly moist for good fruit production and to prevent disorders like blossom end rot.
• Use a watering can or a hose with a rain nozzle to water. Be gentle - a hard spray of water can wash soil out of pots and damage roots. 
• Apply water slowly and thoroughly, so that all of the soil-less medium is moistened and excess water runs out of the drainage hole.
• Don't use a saucer under pots - if plants sit in water for too long their roots can rot.
• It's a good idea to raise your pots off the ground - using pot feet or bricks or whatever you have handy - to enable water to drain freely from the drainage hole.