How much water do gardens need? Often not as much as we dump on them.
One rule of thumb is an inch of water a week – which is about 60 gallons for a garden of 100 square feet. That is for the average garden (outside the South) in decent soil.
Requirements grow by ½ an inch for every 10°F above 60°F or so, more for gardens with water-intensive produce such as cucumbers, zucchini and tomatoes. The baseline is average temperature – daytime high and nighttime low – divided by 2.
Why an inch? An inch of water should penetrate about six inches into the soil, feeding major roots. Careful watering, avoiding the leaves, also uses less water and reduces water-related plant diseases. Water plant by plant near the roots, not by hosing down big beds or setting up sprinklers.
Proper technique is a great start. Implementing a few water conservation habits in the home is the next step and can generate a surprising amount for garden use.
A gallon holds 128 ounces, so the average garden needs 77 ounces of water per square foot each week. As a reference point, a half-gallon jug contains 64 ounces. Brushing our teeth with the water running wastes more than that.
Consider how much water simply goes down the drain in an average home. Tap these ready sources to conserve water and cut your utility bill:
- Catch water from warming up the shower in a pail. A 10-minute shower uses 25 to 50 gallons of water. If the showerhead produces 3 gallons a minute, keeping a bucket under the tap for even 30 seconds while the water warms up means 1.5 gallons per shower.
- Place a bucket outside under a window air-conditioner. These units produce 1 to 2 gallons of condensate each day.
- Rig tubing from a central A/C system condensation outlet. A water barrel placed horizontally can collect 5 to 20 gallons of water a day this way.
- Collect remains from discarded water bottles. I grabbed a few from my car and one from the porch and collected a quart.
- Empty water from a dehumidifier into pails. Depending on model and the climate, dehumidifiers can remove 3 to 8 gallons of water from the air each day.
Keep a bucket in the kitchen. Rinse produce in the sink over a large bowl or pan then dump it in the bucket. Empty pets’ water bowls, too, before giving them fresh water.
Some people siphon bath water and keep pans or bowls under sinks when they wash their hands and brush their teeth. (Many others turn off the water while they brush their teeth).
Invest in a few manageably-sized buckets with good handles and take two at a time out to the garden when they are filled. This is work, yes, but it also is a great workout. Just remember to lift with your legs.
Your back, your biceps, your budget and your planet will thank you.