How to Water a Window Box


Watering a window box may seem similar in theory to watering houseplants. However, you have additional variables to consider. Since window boxes are exposed to the elements, they often require more frequent watering than houseplants. They also require more frequent watering than a traditional garden, because there simply is not enough material in a window box to retain moisture as long as in a traditional garden. Much of the guesswork in window box gardening can be eliminated with the use of a moisture meter.

Step 1

Install a moisture meter in each window box according to the manufacturer's instructions. Usually, you will just need to stick the probe into the soil.

Step 2

Water your window boxes until you see water run out the drainage holes. Do not overwater.

Step 3

Monitor your window boxes carefully, especially in dry, hot weather. Your moisture meter will tell you when the boxes need watering. In some cases, you may need to water your window boxes twice a day.

Tips and Warnings

  • Do not assume that your window boxes have had enough water just because it has rained. Always check your moisture meter. Make sure that no water is lingering between the window box and your house. You may need to change the configuration of your window box if this happens. Moisture that is constantly trapped between a window box and your house can lead to damage and rot, both of the window box and your house. Do not use a garden hose without a spray attachment when watering window boxes. Its increased power will wash soil away and may also displace seeds and young seedlings.

Things You'll Need

  • Moisture meter(s)
  • Watering can (optional)
  • Garden hose with spray attachment (optional)
  • Mulch


  • Organic Gardening: Window Boxes
  • Ask the Builder: Window Box
Keywords: window box watering, moisture meter use, window box care

About this Author

Amrita Chuasiriporn is a professional cook, baker, and writer. In addition to cooking and baking for a living, Chuasiriporn has written for several online publications. These include Chef's Blade, CraftyCrafty, and others. Additionally, Chuasiriporn is a regular contributor to online automotive enthusiast publication Chuasiriporn holds an A.A.S. in culinary arts, as well as a B.A. in Spanish language and literature.