Roots and Shoots: What to Do About the Water

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As unintuitive as it sounds during a drought, fall is a good time for planting if you can sort out a watering schedule that meets conservation requirements. This is true because, while new plantings need regular watering, established plantings usually do not, depending on the type of plant and if it is planted in the right conditions. 

If I create a flowerbed in May, I need to water it throughout the spring, summer and fall. The same goes for shrubs and trees. But during the next growing season, native plants, certainly, and some ornamentals, will survive under typical conditions without supplemental water. 

By planting in September and October, the watering schedule is reduced to a few months, until the plants and trees go dormant after the first frost. Gardeners who have multiple projects, like landscaping and vegetables or fruit to tend and maintain, can shift the work of the landscaping to the fall and focus on growing food in the spring and summer. 

Put your roof and downspouts to work collecting rainwater. Photo by P. Doan

Put your roof and downspouts to work collecting rainwater. (Photo by P. Doan)

But … the water. Rain barrels for everyone! Using a 2-gallon watering can, I know that I use 4 gallons every day to keep plants alive in pots on my patio. The plants are a mix of perennials, herbs and seedling trees waiting for transplant, and a few annuals that I planted from seed. The few veggies that I’m maintaining right now need 4 gallons, as well. 

I have also been watering a dozen new perennials with another 2 gallons or so every few days. That adds up to roughly 10 gallons per day for plants. In a month, that’s 300 or more gallons of water going to plants. 

In other years, there has been rainfall to offset those numbers, but high temperatures and lack of rainfall create conditions where that water is used up quickly. 

For comparison, the average dishwasher uses 4 gallons, a five-minute shower can use 15 gallons and running a sprinkler for an hour three times per week can add up to more than 12,000 gallons in a month. 

The average New York resident uses 79 gallons per day for personal hygiene, cooking, cleaning and hydrating. If you’re washing your car or watering a lawn or garden, it’s easy to see how that number can jump dramatically. 

To spare using groundwater pulled through my well, I could offset my plants’ needs with a rain barrel or two, or four or six. With a connected system of 50-gallon barrels, I could feasibly collect 200 to 300 gallons to save for a dry day. During a season, that could mean significant conservation. 

What to do about veggies, though? I’ve always had concerns about using rain-barrel water for plants that produce food. It’s roof run-off and there can be high levels of pathogens (e.g., squirrel poop with E. coli), metals and other compounds washed into your collection system with that first rinsing rush. Although studies have shown that there is low-to-moderate risk of transmitting these to your plants, there are best practices that can make supporting vegetables with rain barrel-collected water even safer:

  • Set up a first-flush diverter to allow the rinsing rain to run off, rather than into your rain barrel. This needs to be sized correctly and there is a lot of information online about how to do it. 
  • Periodically clean the barrel with a bleach solution to prevent or lower the risk of contamination and spreading pathogens. 
  • Water plants at soil level and avoid spraying foliage to prevent uptake and contamination. 
  • Water in the morning at the soil level and wait until the water evaporates from the foliage later in the day to harvest. 
  • Send water samples from the barrel for testing to determine quality and safety. Since this is a dynamic system, it’s a snapshot of a certain moment but can add insight. 

As the drought has extended itself, I’ve resorted to only using gray water for plants and have ruthlessly asked myself, “Does this plant bring me joy?” I’m looking at you, gardenia. It’s easy to go on autopilot with watering and not question what is necessary until the situation becomes severe. But water conservation is a smart path to pursue under any condition. 

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