Once upon a time, a friend had a summer job at premier nursery in the Pacific Northwest. She said that the nursery owner always had his new employees spend the first two or three weeks doing nothing but watering plants.
By teaching his staff how to water plants properly, the owner ensured the health and vitality of his seasonal inventory. But he also used this period of initiation to identify the best employees: people who paid attention.
When it comes to watering, there are no hard or fast rules. It’s a judgment call that depends on the type of plant, the soil, the wind and weather, the time of year and many other variables. Fortunately, it’s easy to figure out what to do: You just need to check the soil.
If you’re working in a nursery, you check plants by lifting each pot before you water. Over time, you get to know how heavy a pot should feel if the soil inside the pot is thoroughly moistened. If it’s not heavy enough, you water slowly until all the soil in the pot is moist and water runs out the bottom. Then you lift the pot again to check that it feels right.
When it comes to containers, watering is of no value if the water simply runs down the outside of the root ball, leaving the roots at the core of the plant dry. This can happen if you water too quickly (are we in a hurry?) or apply too much water at once.
Slower watering is usually more effective. The key is to ensure that water gets to the root zone, whether you are tending seedlings, watering houseplants, watering a row of tomatoes in your hoophouse or soaking thirsty rhododendrons.
Thing is, you can’t use the “lift test” in your garden of raised beds or landscaped areas. Nor is it a good idea to water without thinking. Feel your soil! When the soil sticks in your hand and you can form it into a ball, it is moist enough. But, if it barely holds together in the palm of your hand, or if the surface looks hard or feels like Rice Krispies, it’s probably dry and it’s time to water.
After our cool spring, heat spells can be quite a shock for plants. And while I can’t predict what kind of weather we can expect for the rest of the summer, I thought it would be helpful to provide some watering tips.
Water, by the way, is one of the main highways for carrying nutrients to plant roots, making up 25% of good soil. Soil acts as a storage reservoir when moisture is not replaced by rainfall, soaker hose or sprinkler. How much water can the soil hold depends on its texture and organic matter content.
Kodiak’s native soil — some folks call it “butter clay” — dries out quickly, but there’s an easy fix: Add compost and mulch. Before you know it, you are well on your way to making rich, well-balanced soil. Regular applications of modest amounts of compost will dramatically improve your soil’s water retention and help suppress disease.
FIVE TIPS FOR WATERING YOUR GARDEN
Focus on the root zone: Remember that it’s the roots that need access to water, not the leaves. Wetting the foliage is generally a waste of water and can promote the spread of disease. This is especially important to remember in enclosed spaces such as greenhouses or compact plantings.
Water deeply and thoroughly: Lawns and annuals concentrate their roots in the top 6 inches of soil; for perennials, shrubs and trees, it’s the top 12 inches. In heavy soil, it may take hours for water to percolate down 6-12 inches. Use your finger or a shovel to check the progress.
The best times to water: Water loss is highest during midday, and lowest at night. So if you do get moisture on the leaves, this gives them time to dry out. It’s much more difficult for plant diseases to get a foothold when the foliage is dry.
It’s also a good idea to water before you weed. In damp soil, weed roots loosen their grip on the other side of the earth when you pull. Water seedlings after transplanting seedlings and after thinning carrots, beets and other root crops. Moistening the soil around the plants helps the soil settle in. I like to think plants feel “tucked in.”
Mulch everything: Mulch reduces surface runoff and slows evaporation from the soil.
Use the right tool. For efficient watering at the root zone, use a soaker hose or an even more precise drip irrigation system instead of a sprinkler.
Rain water vs. tap water: Although they still grow when watered with tap water the results you get from watering with rain water are vastly improved. Studies show that chlorine and other substances in treated water can inhibit the uptake of nutrients and thus reduce plant growth and health. I’ve witnessed this many times. I can be watering with municipal water for a week or so, but when it rains, plants seem to spring with joy.
True or false: Any water sitting on leaves in full sun acts like a magnifying glass and burns leaves.
Answer: False. Magnifying water droplets is one of the most persistent gardening myths. Water droplets do magnify a little, but not enough even to warm the leaves, let alone burn them.
Never take water for granted. Water covers nearly three-quarters of the planet, but only about 3% of that water is fit for use by humans and animals, or for watering plants.
As for what’s in store for us this summer, here’s what the Farmer’s Almanac says for the Annual Weather Summary for Alaska: “Summer will be slightly warmer than normal, with the hottest period in early July. Precipitation will be above normal in the north and below normal in the south.”
In a perfect world, it would rain every third day between 2 and 4 o’clock in the morning.
Deadhead annuals and perennial flowers.
Weed. Weed some more.
Share greens with your neighbors.
Go on slug offensive maneuvers. Yes, the little buggers hide in the shade.
Sow more lettuce, spinach, salad greens, peas, broccoli and kale.
Thin carrots, radishes, and beets.
Hoophouse and greenhouse folks: Be on the alert for gray mold and aphids. Keep the fans running and avoid overhead watering.