El Niño Finally Arrived – Now What?

Headshot of Nan StermanWe’ve had our first taste of El Niño rains; four inches in three days! That’s almost half the rainfall we normally see in a year. Fortunately, we prepared ahead of time. The plumber came out a few weeks ago to clear in-ground drains. The tree trimmer lightened the canopies on our largest trees. The rain gutters got cleaned out, too. All were time and money well spent.

Many people ask me how to protect their plants from rains but that’s not really an issue. As I mentioned in a recent radio interview about El Niño, when it rains, plants do a happy dance. Water doesn’t hurt leaves or stems or branches. The risks instead, come from what happens to the water once it hits the ground. Standing water can drown plant roots; plants can be washed away in a mudslide or by fast moving water, or undermined by erosion.

How do you prepare for El Nino rains? Here’s my to-do list:

  • Clean out rain gutters so water doesn’t cascade over the sides and smash the plants below.
  • Redirect downspouts to disperse water into bio-swales. From there, it will slowly percolate into the soil. If you have poor draining clay soils, install rain barrels to save the water, then use it once the garden dries out.
  • Check drains to be sure they work properly. Clear clogs to avoid flooding.
  • Turn over pots, buckets and any other open containers that might collect and hold water long enough for mosquitoes to breed in.
  • If you collect rainwater in open buckets, put a lid on the buckets between downpours.
  • Protect bare slopes from erosion. Install straw wattles horizontally across hillsides. Wattles are essentially mesh tubes filled with straw and staked in place to serve as speed bumps as water runs downhill. By the end of the season, the straw will break down and can be emptied onto the soil. Compost “socks” are similar to wattles but are filled with compost.
  • Manage the water in your rain barrels. Don’t collect water from the first rain. That “first flush” carries chemicals, dust that settles from the air, dirt, bird poop, debris, etc. Let that water go and capture the next rainfall.
  • Renew your garden’s mulch. Organic mulch — that’s mulch made from leaves, bark, wood, etc. — traps water as it falls. That protects soil from erosion and absorbs water like a sponge. Once water percolates into the soil, mulch helps keep it there by slowing evaporation. And, as mulch breaks down, it builds healthy soil to support the plants in your garden.
  • Turn off your irrigation. If we get a long, hot dry spell or Santa Ana winds, you’ll need to water. That’s unlikely to happen more than a time or two between now and the end of March.
  • Use the time between storms to plant. Plant any of our native plants and plants from dry climates of South Africa, Australia, Chile and the Mediterranean coast. Make your plans, do your research, then head to the nursery. Don’t plant right away, however. Let the soil dry for three or four days after a rain. Digging and standing on wet soil compacts it, the opposite of what we want to do.
  • When you do plant, plant directly into unamended soil. Research tells us that plants in “native” soils do better than those in amended soils. It’s OK to toss in a few handfuls of worm castings, but skip the fertilizer and don’t bother with soil amendments.

Remember this year’s rains are to be welcomed, not feared. While they won’t solve the drought, every drop certainly helps. Sadly, the El Niño rains won’t end California’s drought. But if you capture some of that rainfall, you can use it later in the year, after the rains end and the soils dry out. Shop for rain barrels and learn about rainwater harvesting at your local garden center or irrigation store.

Nan Sterman is a garden expert, author, designer, and educator. Nan leads international garden tours and hosts the show A Growing Passion on KPBS TV. Learn more about Nan at plantsoup.com.