By Sally Cunningham
All across Western New York, gardeners are watering the tomatoes and daylilies. Some homeowners are sprinkling the lawn. Some folks have learned the lesson about recently planted trees, shrubs, and perennials—that require the most water during their first years in the ground.
But who is taking care of the old trees?
The current drought: How bad is it?
The New York State Drought Monitor has declared that much of Erie County (and large parts of neighboring counties) is in Moderate Drought Status. As of July 14, we are the only significant region of the state with that designation. Technically “moderate” is labeled a “D1” level, which means there is lower surface water and lower than average soil moisture. The category carries these warnings:
- More irrigation is needed
- There is threat of wildfires
- Voluntary water conservation may be requested
In practical terms, it means you see lawns browning early, premature tree leaf drop, and wilting and stunting of flowers, fruit, and vegetable plants. Farmers face likelihood of stunted crop growth–including grain yields, and a decline in honey production. In your garden you may see cracked stone-hard clay soil, which causes water to run off rather than penetrate to where plant roots are.
It’s not just the amount of rainfall
According to the News Weather Service Office at the Buffalo airport, from June 1 to mid-July our region received an average of 3.33 inches of rain, which is nearly fifty percent below normal. (Normal would be about 4.76 inches.) Naturally, those inches did not fall equally on everyone, so some farms and gardens received even less. And not every producer or homeowner has the irrigation set-up, or the physical or financial ability, to get water to where it is needed.
Even more than the inches of rain, the frequency and pattern of rainfall is crucial. After many weeks of drought, one heavy rainfall can’t solve the problem for several reasons. Water rolls off the soil surface before plant roots can absorb it. Also cell-level changes have happened in the plant (reverse osmosis, cell membranes shrinking) so that root hairs die. It takes time and multiple episodes of penetrating rain to let plants begin to catch up. For some, the structural damage is so severe that the plants cannot recover.
Tom Draves (Draves Tree Service) is a greatly respected arborist who added this warning: “If we get an inch of rain next week, don’t think it’s enough.” That rain would be good, but his concern is that home gardeners and even some professionals might think that the drought is over and they can stop the watering. We have a long recovery period ahead.
The other major factor is the choice of landscape plants and their placement. If a tree or shrub is planted properly in a site where it belongs, it is the most likely to survive long-term weather patterns and times of hardship. But each species has a specific level of drought tolerance. For example, birches, willows, and most evergreens have limited tolerance for drought periods. (Notice the beautiful River Birches that have become so popular—deservedly–and see their interior leaves yellowing: that’s a clue to drought stress.)
Tom Draves developed Draves Arboretum in Darien, New York (a Level III Certified Arboretum) to show the public and professionals a vast collection of trees that can grow in realistic Western New York soil and conditions—unpampered.
What to do first
In last month’s article, Lakeside Sod staff and I presented how to water properly, and I hope readers will review it. All the info is entirely relevant now and even more important. Key points are:
- Get the water to where the roots are, whether that is 3 inches for turfgrass or 2 feet for larger plants. (Dig a hole to see how deeply the water reached.)
- Do not just water the soil surface. (Many sprinkler systems are inadequate, spraying water ineffectively and losing much to evaporation.)
- Water one area of your yard or garden at a time, and do it well. (Switch to another area another day.)
- Don’t fertilize most plants in dry periods, as that adds stress to produce new growth when the plant can’t take up moisture for the foliage it already has.
- Don’t prune most plants in dry periods, since pruning cuts tell the plant to re-grow just when it needs to take it easy.
- Mulch bare soil where you can, with 3 inches of organic material, and be sure your watering gets to the soil. Mulch will help retain soil moisture, but if you are watering shallowly you might just be wetting the mulch.
- Morning watering is ideal. But water whenever the plants need it. (Let your drooping hydrangea tell you when you are late with the watering service.)
- Pull the weeds since they are stealing the water from your chosen plants.
For specific landscape and garden groups:
Mature Trees: These are the most neglected plants, with the worst consequences if ignored during droughts. (Think of the cost of tree replacement, or even the cost of removal.) Yet most people diligently water their tomatoes or petunias but think the tree will just live on forever.
To water a mature tree: Soak the root area deeply (the top eighteen inches of soil at least) from the trunk to the outermost branches (under the whole canopy), every 3 or 4 weeks. That means gallons of water, delivered by an in-ground water system, or (more likely) by moving a hose around the root area for 3 or 4 hours. Ideally, dig a hole sometime to see where your water went. Also learn the needs of the different tree species around your home, since their requirements for beauty or survival are different.
Small trees or shrubs: The same rules apply, especially for anything planted in the last two to three years, because their root systems are small. You might try “tree collars” or “tree gators” that collect the water and deliver it slowly. A home remedy is to place several 5-gallon buckets with holes in them, over the root areas, so that the full buckets of water seep out slowly.
Flowering perennials or food plants: Except for tiny, new plants, don’t water daily. Do water deeply, every two to six days, depending on the heat, wind, soil, and status of the plants. The current moderate drought (June to July 2022) would be much worse if the temperatures had been higher. Cool nights helped wth some soil moisture retention.
Container plants, window boxes, and hanging baskets: These likely need daily watering. It may help to move some out of the hottest sun during this time. It’s okay to add a few new plants from the garden center or nursery as long as you can keep up the watering.
For turfgrass: Take the advice of Lakeside Sod professionals and other CNLPS (Cerified Nursery and Landscape Professioals) about watering practices for newly seeded or sod lawns, as watering is all-important. However, in many situations, established lawns can go dormant and turn brown for several weeks without severe consequences. If they were reasonably healthy with decent root systems, those brown lawns will turn green again when rainfall returns. (Some say it’s better to have given that water to the tree?)