So How Much Water Do Your Plants Need?

It depends on a number of things: 

Origin

From where did the plant species originate (rainforest, desert, etc.).

Tissue type

Is it woody like a tree or shrub (You need a saw or clippers to prune it), or herbaceous like a geranium (You can squish it with your foot)? Woody plants can go weeks without water. Most mature trees can thrive on monthly deep watering.

Structure

Plants with small, narrow, and tough foliage can survive without water the longest. Plants with big, soft, thin leaves will require the most water. However, there are always exceptions.

Maturity

Older established plants do not require the frequency of water that young plants require. But when you do water, soak ‘em good!

soil type

Plants use water at the same rate and amount regardless of soil type, but heavier soils stay wet longer that sandier soils and need to be watered less frequently than sandier soils..

weather

Temperature, wind, humidity, solar radiation (sun intensity). Guess which factor will dry a plant out faster: high temperature or high solar radiation? It’s solar radiation. Air temperature is indirectly dependent on solar radiation.

microclimate

Sun or shade exposure, reflected heat, low lying areas (frost), water runoff, obstacles to air flow (hedges, fences), etc. all have effects on the rate of water use by plants.

 

Bottom line: Don’t be afraid to experiment. 

Skip watering for a week and see what happens (nothing will happen - unless it is super hot). Then try two weeks, three weeks or more, until you see signs of stress (pale leaf color, wilting). You will be shocked at how long your plants can go without water. When you do water, soak the heck out of your soil so all roots get some water.

  Image © Inland Empire Landscape Contest

Image © Inland Empire Landscape Contest