Thoughts on Watering

On Thursday 2/26/15, a school garden training program will be held in Traverse City; please note our previous post on that event. As a small part of the proceedings, I'll be saying a few words about watering food garden plants. As a friend of mine is wont to say, "Everything has to have a drink." Here's an outline of what I'm planning to say:

Conserve water when possible

• Whether planting indoors or out, start with planting mix or soil with structure that holds water well.
• Add organic matter as needed to improve soil structure.
• Mulch with material that dries quickly on the surface but reduces evaporation from soil.
• Learn which plants require more water and which can do without; apply only what’s needed.
• Most plants, even in sandy soil, can do well with less than the equivalent of an inch of rain per week.  That’s about 60 gallons per week per 100 sq ft of root zone.
• Use a rain gauge to help determine when plants have received sufficient water.

When starting from seed:

• Especially indoors:
• Premoisten soil or mix before planting.
• Apply a light mulch, e.g., milled sphagnum, which dries quickly, reducing chance of fungal pathogens.
• Cover containers to reduce evaporation, but watch for fungus growth!
• Mist or gently sprinkle soil surface twice daily as needed to keep moist until germination is evident.

After germination:

• If indoors, move to a cooler area and begin bottom watering to keep surface relatively dry to reduce chances of disease, e.g., fungal “damping off,”
• If outdoors, gradually allow soil surface to dry before additional watering.  Don’t overwater, but make sure soil several inches below the surface is moist.
• If in doubt, squeeze a soil sample tightly; if it “clumps” together, it’s too wet.

As plants grow:

• Learn which plants require more or less water and apply accordingly.

• Water the soil over plants' root zones, and avoid unnecessarily wetting the foliage.
• Root zone can extend laterally more than twice as far as the plant’s drip line; water the root zone, not just the stem area.
• Water early in the day so that foliage can dry before night; and evaporation losses are lower then.
• Water less often; with well-established plants, twice a week should be enough.
• Add extra mulch (straw).

Methods:

• A sprinkling can is fine for a small school garden; and remember: kids love to water!

A watering can with a long spout allows a child to water plants without walking too close.

• Develop child sense of pride in nurturing.
• Teach awareness of plant below-ground structure.
• Sprinklers or sprays are good for germination and very early growth, but:
• Ground-level drip irrigation systems are much better for established growing plants.
• Less likelihood of disease.
• Less water waste to evaporation.

See: http://communitygardennews.org/gardenmosaics/pgs/science/english/mainscience.htm

       Click on Watering Garden Plants, etc.