We all know the heat is coming; it’s only a few weeks away. Rather than react, I act now by taking a few simple steps to keep the landscape green, growing and resilient.
While watering is the first thing that comes to mind, I begin by choosing the right plants for my site and improving the soil’s water-holding capacity with annual additions of compost. I live on a well, so the plants I choose must be drought tolerant. Native perennials I enjoy growing are Blue Indigo (Baptisia spp.), Blue Star Flower (Amsonia spp.), St. John’s Wort (Hypericum spp., Yarrow (Achillea spp.) and Caroline Lupine (Thermopsis caroliniana). In the shade I suggest Foamflower (Tiarella spp.), Crested Iris (Iris cristata), Christmas Fern (Polystichum acrostichoides), Leatherwood Fern (Dryopteris marginalis), Solomon’s Seal (Polygonatum biflorum), and the non-native Robb’s Wood Spurge (Euphorbia amygdaloides var. robbiae).
While I plant perennials in the fall and spring, I do my best to plant trees and shrubs in the fall. This gives the roots time to grow before the summer heat arrives. With spring planting, some plants succumb to transplant shock during those first hot days of the season. Signs of a stressed plant are easy to spot: it wilts consistently on sunny days but perks up when it's cloudy, even if the soil is still moist. To reduce transplant shock, I shade the stressed plant for three weeks or more and I am very creative with my shade structures. I have used a large umbrella, a chair draped with a sheet, a simple “A” frame-style tent, upside down large wicker baskets, shade-cloth and tarps. Anything to provide so the plant can establish itself.
Regardless of when I plant, I only dig a hole deep enough for the root mass. I do this so the crown of the new plant won’t sink lower than ground level. It’s best to plant a little higher for a healthy root system than too deep and deprive the roots the oxygen they need. After planting, I mulch both the plant and the surrounding area — much like frosting a cake, flat and evenly spread out at about 2” deep. Even a little mulch makes a difference in retaining soil moisture, reducing weed competition and buffering the soil temperature from the heat of the sun. I also mulch my containers and particularly my vegetable garden! Mulching definitely conserves soil moisture.
How to water and when to water is also important. I rarely use sprinklers because most of the water thrown into the air evaporates before it hits the ground. Instead, I apply water to the root zone by hand watering with my garden hose, focused watering with a container, or using drip hoses. Drip hoses have evenly spaced emitters which control water seepage along the entire hose length. Soaker hoses don’t have pressure regulating emitters and often there is no water left at the end of the hose run. I don’t water during the heat of the day to avoid water loss due to evaporation, watering during the cooler times of the day is best. When night watering please remember to factor in the increase in water pressure after 8pm and before 6am. This occurs due to the drop in residential water usage during these hours. One night I found water spraying out of an entire drip hose due to the drastic increase in water pressure! What a mess!
Using a variety of methods I target water plants recently planted rather than the entire bed, it’s more sustainable. Commercially available watering bags are great for trees planted within the past year. Donut shaped watering devices for shrubs are also perfect for target watering. However, I like to reuse one-gallon containers with a lid for target watering. Using a sharp knife, I stab the bottom of a cleaned container three times. Next, I fill it with water and very loosely cap it to allow air in while keeping debris out. I set the dripping container at the base of the target plant. If watering a tree or shrub, I refill the empty container and place it on the opposite side to water those roots. Typically, I water trees and shrubs once a week and increase this to “as needed” during a drought. This month is the perfect time to start collecting one gallon containers for target watering this summer.
For gardeners with irrigation systems, installing a rain sensor makes sustainable sense. This inexpensive device stops the water flow if more than ¼” of rain falls during a storm. Another sustainable step is to incrementally reduce the frequency of watering to once a week while raising the lawn mower cutting height to 4”. The taller grass and less frequent irrigation will encourage roots to grow deeper, reducing the dependence on the automatic watering system. Water is a finite resource and during drought conditions lawns can easily survive without irrigation. While many think a brown lawn is dead, it’s not, instead the lawn is dormant. Once rain falls the dormant lawn will revive to a lovely green. This is truly amazing and I’ve witnessed this time and time again in my career — grass is tougher than most people think.
Resilient landscapes are tough by nature. Their strength comes from selecting the right plants, improving the soil with organic matter, and fine-tuning watering practices—and May is the perfect time to begin.
Happy Gardening!
Peggy
