FARGO, N.D. — Do you remember your first job?
Maybe you were a babysitter or worked at McDonald’s. Maybe you delivered newspapers.
My first job was unusual. I was a trained assassin.
A research company trained me to torture and assassinate sunflowers.
Every day I grew deadly diseases in the laboratory. Every night I would attack the sunflowers with those diseases.
I was taught the key to killing plants was improper watering. I turned on the sprinklers in the field to get the plants wet and then spread the diseases at night. The diseases loved the moisture and humidity.
Don’t irrigate plants like that. Keep the plants dry and don’t irrigate at night.
The best time to irrigate is during the morning. Plants in the morning actively absorb what they need, and then have all day to dry off until the dangerous nightfall.
Don’t irrigate during midday or during high winds. You can lose a third of the water before it is absorbed by the plants. Water is too expensive to waste.
Keep the leaves as dry as possible when irrigating. Target the water toward the roots, where plants drink.
Irrigate deeply and infrequently, not shallowly and frequently.
If you water deeply, the roots will grow deeply. If you water shallowly, the roots will stay near the surface and be more sensitive to drought. Roots grow where the water is.
It is better to irrigate deeply once or twice a week than irrigate shallowly more often.
Plants in gardens need an inch or two of water per week either from your hose or from rainfall. You can set out containers in the garden to estimate how much water is an inch.
Use common sense when watering. Plants need more water when it is hot and dry. Drooping plants are a sign the plants need a drink.
Do not splash soil on the plants when you irrigate. Many blights that kill our tomatoes and other plants come from the soil. When you splash the soil on your tomato vines, you are spreading diseases on the leaves. A soaker hose or watering wand can help to minimize soil splash.
Mulch can help. Mulch acts as a barrier that prevents soil diseases from splashing onto your plants. Mulch also conserves the moisture in the soil.
The next time you water your plants, do it correctly. Irrigate in the morning. Apply the water at the roots and irrigate deeply. Don’t let your plants become the latest victims of an assassin.
For more information about gardening, contact your local NDSU Extension agent. Find the Extension office for your county at https://www.ndsu.edu/
— Tom Kalb, NDSU Extension