Water, Water anywhere?
By Sue Goetz
As drought reveals itself in the Pacific Northwest, we watch our typical lush, green surroundings turn shades of tan. Just like the hot weather, watering the garden is a hot topic.
Here is what water-wise gardeners should know:
The obvious…plants need water.
The less obvious, how they get it and survive. Watering the leaves to cool off the plant probably feels like you are doing something good for the garden, but most of the time, little water gets down to the roots. Think of it like this: imagine you are thirsty and instead of taking a drink of water, you take a shower. You might feel cooler, but it does not satisfy the thirst. That is what it is like for plants; they need water in the soil and around their roots to allow the plant to get water to the stems, leaves and flowers.
How do you know if you’ve watered enough?
It can surprising how much time it takes to get water to the needed depth of soil.
Water the garden as you normally do and wait about 10 minutes. Then check your garden’s soil moisture.Take the gloves off and push fingers into the ground around your plants in different areas of the garden. Dig in with a trowel too.
In an area with sufficient water, the soil should be thoroughly moist after each watering…all the way down to the root zone. The top 2 or 3 inches of the soil may be semi-dry, but the soil below that should be moist to a depth of 5 to 6 inches or more.
Get down deep
Established plants also need deep watering to keep roots far down into the soil. If they are given water only at the surface, they get lazy and don’t have to work hard for their water. In periods of drought, shallow-rooted plants can’t stay cooled by the soil, so they stress and wimp out. Hanging out with a hose spraying a garden bed or the lawn for 15 minutes just doesn’t do it. It might settle the dust for the day but does not get enough down into the root zone where plants need it. Instead of daily, light water, do a good weekly soaking that allows the soil to become wet to a depth of 6 inches. If your system of watering, either sprinkler or by hand does not do this, adjust to a once a week deep watering to ensure good subsoil moisture that is consistent. Just because it is hot, doesn’t mean you have to water every day. Container gardens are the exception! Plants in the ground need to get the available water from the soil before watering again. Deep water will help roots grow deep.
Maybe it’s your soil
Improving your soil’s moisture-holding capacity is as simple as mixing organic compost into your beds. Depending on the type of soil, more organic matter means more water is accessible to plants. Dense clay particles rob most of your soil’s moisture, decreasing the amount of water available to plants while sandy soils drain water too quickly for plants to absorb it. An amendment can help the soil structure of both clay and sandy soils for more efficient water holding.
In warm weather, water in the morning to give plants a chance to drink up before the hot sun and the wind evaporates moisture. If you can’t water in the morning, try for late afternoon, but not too late. The foliage should have time to dry before the sun goes down to help protect plants that are prone to fungal diseases. Powdery mildew and spider mites love to thrive in warm weather AND moisture.
Mulch reduces water evaporation by helping to trap moisture on the ground during dry times of the year. Use a good organic compost to help nourish the soil in planting beds. Spread up to 4 inches deep all over landscape beds. Do not pile mulch near the base of plants, keep it shallow to avoid rot. In established planting beds topped with bark, occasionally rake the old mulch to break up the soil surface. A good raking (not scraping) to fluff the surface of the soil will help water penetrate through.
Brown lawns are okay.
By the way if you have joined the ranks of the brown lawn brigade, all is well. The heat and lack of moisture have pushed it into dormancy and as soon as natural rainfall returns it will bounce back with vigor. Just don’t allow heavy foot traffic or the dog to tear it up too much. In the spring as it actively begins to grow again, pay extra attention to keeping it healthy.