A gardener’s judgment is key to effective summer watering
“The watering of a garden requires as much judgment as the seasoning of a soup.”
— Helena Rutherfurd Ely, “A Woman’s Hardy Garden,” 1903
The other day I visited renovated Hawthorne Park, where I was delighted to see several families taking advantage of shade from the conifer grove for picnics. Lots of children were playing on the new playground equipment and having a grand time dashing around the park’s splash pad.
All the water fun reminded me of how much the plants are enjoying the water they’re getting from the automatic drip system in my garden. Unlike the young park-goers who can rush from one geyser to the next, my vegetable and flower plants must wait for nature or gardener to bring the cool, refreshing wetness to them. For the healthiest, most productive plants, consistent watering is key.
In my vegetable beds, emitters attached to the drip hoses release water at the rate of 1 gallon per hour. So far, the plants have been thriving with 10 minutes of watering set on a timer in the morning and 10 minutes in the late afternoon. (My garden must contend with late afternoon heat, so I’ve found that the plants do best with a second dose of refreshment once the day’s temperature tops off.) Positioning the emitters within the root zone, rather than at the base of the plants, allows for optimal moisture uptake, and it has significantly reduced the need for weeding.
An automatic drip system ensures watering consistency; yet, as Helena Ely suggested, it’s important for gardeners to continue monitoring the plants and make adjustments as needed. For example, hot winds hasten moisture evaporation, so if a finger probe a few inches below the soil’s surface comes up dry, I’ll supplement the automatic irrigation with watering from a garden hose.
It’s essential that garden soil stay moist (but not wet) during flowering, blossom set and fruit development. Accordingly, this month keep an eye on blackberries, blueberries, beans, cucumbers, eggplant, melons, peas, peppers and tomatoes, making adjustments to their watering schedule as needed.
In addition to adequate moisture, peppers and tomatoes that are blossoming and setting fruit will benefit from supplemental magnesium provided by a monthly foliar spray of Epsom salt (magnesium sulfate). The OSU Extension Service recommends a ratio of 4 tablespoons of Epsom salt per one gallon of water to increase crop production and sweetness.
On the other hand, crops in the allium family require less water when the foliage begins turning yellow. The tops of onions, garlic and shallots will flop over once the bulbs are fully developed; this is the time to stop watering to prevent bulb rot. After a week or two, dig up the bulbs and cure them for a week. Also, keep an eye on potato plants for the next few months because they will need less water once their top greenery begins to die back.
Several plant problems are at least partially due to uneven watering. These include tomato blossom-end rot, cabbage head splitting, and premature head formation, or buttoning, of cauliflower and other cole crops. Improper watering also places plants at greater risk of diseases such as gray mold, blights, bacterial leaf spot and root rot.
The good news is that many of these problems can be avoided by consistent watering aimed at the plant’s root zone, rather than at its leaves or the base of its stem. Such care is all the more critical when hot summer weather forces garden plants to divert energy to defend against heat stress at the precise time they should be focusing on flowering and fruiting.
So, let’s heed Helena Ely’s advice and use our best judgment when watering this month. The care we provide for our vegetable plants now will lead to delicious soup later on, no matter how much seasoning we decide to add to the pot.
Rhonda Nowak is a member of the Jackson County Master Gardener Association and teaches writing at Rogue Community College. Email her at firstname.lastname@example.org.