Tag Archives: rainfall

Creating a Rain Garden

Do you want a garden that’s easy to install, looks good year-round, requires little maintenance, and helps prevent water pollution? Rain gardens are shallow depressions designed to soak up water and support trees, shrubs, and flowers that tolerate both wet and dry conditions. Often located near gutter downspouts or places where water puddles, rain gardens can also be landscaped into gentle slopes or run curbside along streets.

Giant hyssops, switchgrass, and goldenrod are some of the species growing in this rain garden at Cornell Plantations in Ithaca, planted next to its parking lot to absorb and clean polluted storm-water run off. Photo

Giant hyssops, switchgrass, and goldenrod grow in this rain garden at Cornell Plantations in Ithaca, planted next to a parking lot to absorb and clean storm-water runoff. Photo © Robin Simmen.

By absorbing the rain falling on your land, a rain garden can help reduce the storm-water runoff that pollutes our beaches, harbors, and estuaries. People sometimes confuse rain and water gardens. A rain garden is not a pond and won’t breed mosquitoes, which require 10 to 14 days in standing water to develop from eggs into adults.

The next time it rains, observe the direction of water runoff and where it collects on your property. Your roof may be directing most of the rain falling on it into gutters and downspouts feeding into a storm drain; if so, consider diverting this lost rainwater to irrigate a rain garden via underground piping, or construct a surface swale to channel this water to the garden. If your land slopes gently, you can create shallow terraces (one foot deep or less) for your rain garden or dig out a scallop-shaped bed for it in the hill.

The best plants for rain gardens are happy with a “drought and drench” lifestyle. Native plants are highly recommended because they are uniquely adapted to local weather fluctuations. Also, they require little or no fertilizer, are excellent food sources for pollinators, and provide habitat for birds, insects, and butterflies. Once established, their deep roots increase the water-holding capacity of the soil, hold it together, and prevent erosion. Water a rain garden as needed for the first year or so after planting. By the third year, you’ll never need to water it again!

For information on how to evaluate and amend your soil for a rain garden, do a percolation test to see how quickly water is absorbed, decide the dimensions of a rain garden, and prepare and plant the site, read the CCE Suffolk fact sheet on Creating a Rain Garden, and its companion  Native Plants for Long Island Rain Gardens.

Robin Simmen is a former Community Horticulture Specialist for CCE Suffolk. She can be reached at rlsimmen@gmail.com.

Gardening in a Drought

As of the last week of July 2016, the US Drought Monitor classifies most of Suffolk County as being in a severe drought. According to my precipitation records, Riverhead will need 10 inches of rain by the end of October to be on par with what we consider average. It’s currently raining, and let’s hope it keeps up!

Using mulch is key to waterwise gardening and healthier plants. Photo c Robin Simmen

Using mulch is key to water-wise gardening. Photo © Robin Simmen

Living on Long Island, we gardeners wait all winter to get outside and enjoy our yards. Drought presents us with a moral dilemma: Do we continue watering so we can enjoy the bountiful fruits of the vegetable garden, bright blooms, and green grass? Or do we reduce our irrigation and let nature take its course? Here are some tips for water-wise gardening regardless of the weather:

  • Mulch! Mulch everything! Mulch your landscapes beds, your flower pots, and your raised beds. Whether you use wood chips, straw, or grass clippings, mulch helps regulate soil temperatures and reduce evaporation. Providing a 3-inch mulch layer can reduce plant needs for irrigation by up to 50 percent. Review your choices for mulch by reading our fact sheet Types and Uses of Mulch in the Landscape.
  • Plant early. If you’re planting new perennials, trees, and shrubs, plan to get them in the ground either in the fall or very early in the spring, as soon as the ground is workable. This gives plants more time to recover from transplanting and develop roots. Fall planting generally takes advantage of the season’s rainfall, but remember we’ve had very dry falls recently and many plants require irrigation until they go dormant. Warm-season vegetable plants, such as tomatoes and peppers, will still have to wait until spring nighttime temperatures are consistently above 45°F.
  • Garden in raised beds. Planting vegetable gardens in raised beds gives you more control over their growth and water. You can amend the soil in raised beds more fully, creating environments where your soil holds moisture better. Soils rich with organic matter hold onto water and nutrients better than sandy soil.
  • Weed. Keep your beds free of weeds. Not only do they compete with your plants for moisture, but they rob them of soil nutrients and sunshine if left to grow tall. Some weeds even serve as hosts to diseases and insects that prey on your plants.
  • Water efficiently. Plants absorb water through their roots, so concentrating irrigation in the soil zone is crucial. Avoid overhead watering from sprinklers as these are not as efficient as soaker hoses and drip irrigation, and foliage wetness often exacerbates fungal diseases. Drip irrigation can reduce watering needs by up to half. The key to healthy plants is deep, infrequent watering. Try to water in the morning when the natural dew is set. Morning temperatures are cooler and evaporation is lower.
  • Allow your lawn to go dormant. The majority of grasses we grow for lawns are considered cool season grasses (bluegrass, perennial ryegrass and fescue). These grasses are green and grow actively in the spring and fall but prefer to go dormant in summer heat. Letting your lawn go dormant will not harm it and is actually beneficial to both its grasses and our environment. If a dormant lawn is not possible, be sure to follow the rules of deep, infrequent watering, mowing no less than 3 inches, minimizing fertilizer applications, and leaving your clippings on the lawn (contrary to popular belief, clippings don’t contribute to thatch build up and help conserve water in your lawn.)
  • Monitor your plants. Not everything needs supplemental irrigation. If your established landscape doesn’t show signs of drought stress, assume that the plants are finding water.
  • Put the right plant in the right place. If established trees and shrubs are struggling with this drought, they are probably planted in the wrong spot. For example, Japanese cut leaf maples and flowering dogwoods are understory trees. They enjoy morning sun and shade throughout the hot hours of the day but are often poorly planted in the middle of a hot lawn. Take care to site plants where they will perform their best.
  • Recycle your water. If you boil water for pasta, or you have some water left in a drinking glass, collect that water in a bucket to be used in the garden. Once you become aware of wasteful water usage, you’ll quickly discover ways to conserve and recycle.

Information on drought-tolerant plants and more can be found on our website in this brochure: Waterwise Gardening.

Sandra Vultgaggio is Horticulture Consultant for CCE Suffolk. She can be reached by email at sib7@cornell.edu or by phone at 631-727-7850 x387.

How Dry Was 2015?

Last year Suffolk County experienced its driest growing season in over twenty years. Riverhead received only 21.96 inches of precipitation from March 1 to October 31, 2015, which is 9.27 inches less than the ten-year average rainfall for Riverhead. The last four years in particular have seen a steady decrease in our precipitation, averaging only 26.22 inches in comparison with the previous six year’s average of 34.58 inches. We are surely in a dry spell, but only time will tell what 2016 has in store for us.2015 Seasonal Precipitation for RiverheadSo what did last year’s dry season mean for our landscapes? For one thing, we dragged the hose around more often in an effort to keep plants alive. This was especially true for container plantings, vegetable gardens, newly planted plants, and probably your lawn. Then again, if you left your landscapes to fend for themselves last year, it’s possible you’ll notice more winter damage this spring.

New plantings and transplants, especially of larger trees and shrubs, are probably the hardest to maintain in droughty growing seasons. Keeping the soil moist is very important for establishing strong plants. During the first year of planting, be sure to water trees deeply at least once every week during dry spells; with rainfall, once every two weeks should be fine. Applying a two- to three-inch layer of mulch around them will help keep their roots moist and reduce evaporation from the ground.

During the first autumn after planting trees and shrubs, watering them once every four weeks is recommended. In their second year, these plants should receive supplementary irrigation once every four weeks in the spring, once every three weeks in summer, and once every five weeks in autumn. The key to these waterings is deep and infrequent. A plant should always enter autumn and winter with ample moisture in its system. Research has shown that mid-August through September is the most important time to prepare plants to tolerate winter stress. Once winter arrives and the ground freezes, a plant cannot replace water lost to transpiration by winter sun and wind, making it susceptible to winter injury and die-back.

Most gardeners set out a few containers and pots of plants around their yard each year. These are the plants we need to watch closely during consistently hot, dry days. The trick to watering containers is just like any of your other plants: Water deeply! Let the water run until you see it coming out of the bottom of the pot, which will encourage roots to grow longer, deeper, and ultimately healthier and more resistant to dry days. This year consider creating containers filled with such drought-tolerant species as zinnias, gazanias, salvia, lavender, and dusty miller, or design contemporary containers filled with ornamental grasses or succulents. You could also invest in some self-watering pots that take the guesswork out of when and how much to water, so you don’t have to water your plants every day to keep them hydrated.

Last year after the first flush of spring growth, lawns quickly started gulping for rainfall. Many irrigation systems struggled to keep up with the water demand, and many homeowners without in-ground irrigation weren’t willing to set up sprinklers every day. Typically lawns require an inch of water per week, so professionals often recommend letting lawns without irrigation go dormant over the summer. The majority of lawns on Long Island are made up of cool-season grasses (Kentucky bluegrass, perennial ryegrass and fescues). These grasses look and perform their best in the cooler months of April-June and September-November and prefer to go dormant in the heat of the summer unless they are provided with adequate moisture.

Other factors besides drought last year may affect the health of our plants this year. White oaks were severely defoliated by gypsy moths in 2015. Although oaks can recover and push out a new flush of growth in the same growing season, last year’s drought while they were in recovery may be detrimental to their growth this year. Landscapes damaged by Super Storm Sandy may also be set back by the drought as sufficient water is critical to their long-term recovery. And established trees and shrubs that experienced root disturbances from new driveways, fences, pool installations, or any construction job using heavy equipment and machinery, may struggle as a result of the 2015 drought as well. How your landscape will look this year is pure speculation at this point, but bear these thoughts in mind when monitoring the health of your plants in 2016.

Sandra Vultgaggio is Horticulture Consultant for CCE Suffolk. She can be reached by email at sib7@cornell.edu or by phone at 631-727-7850 x387.

Tomato Troubles? There’s an App for That

As Cornell University’s vegetable pathologist doing research at the Long Island Horticulture Research and Extension Center (LIHREC) in Riverhead, NY, I’ve seen a lot of sick tomatoes over the years, and I’ve been posting photographs of what I’ve seen on my website: http://livegpath.cals.cornell.edu/gallery/. When not at work, I’m an avid home gardener, too, so I have first-hand experience with the diseases popping up in Long Island gardens. In fact, many photographs on my website were taken at home.

Septoria leaf spot symptoms usually first appear on the lowest, oldest leaves after fruit start to ripen.

Septoria leaf spot symptoms usually first appear on the lowest, oldest leaves after tomatoes start to ripen.

This year my tomatoes have Septoria leaf spot, which started on one plant and has been slowly spreading to others. The spores of this fungal pathogen, Septoria lycopersici, are spread by splashing water. It hasn’t rained much this summer, and I usually water at the base of plants rather than use an overhead sprinkler, but the few rains we’ve had spread the pathogen a lot. Septoria gets into a garden when seed containing the pathogen or infected seedlings are planted, or a windy rainstorm moves it from a nearby infected plant. Once in a garden, this pathogen survives overwinter in tomato debris; hence the recommendations to remove infected plant debris and to rotate the areas where you grow tomatoes. Other diseases and disorders I’ve seen on my garden tomatoes include anthracnose and blossom end rot (both every year), drought stress on leaves, leaf mold, powdery mildew, and late blight, all of which appear on my website.

Small dark brown spots with tan centers containing very tiny black specks called pycnidia (spore structures) are characteristic of Septoria leaf spot.

Small dark brown spots with tan centers containing very tiny black specks called pycnidia (spore structures) are characteristic of Septoria leaf spot.

Recently some colleagues and I at the American Phytopathological Society, including Dan Gilrein and Margery Daughtrey from LIHREC, developed a new app for smart phones called Tomato MD. It costs $2.99 and is available for both Apple and Android phones. Learn more about it here: http://www.apsnet.org/apsstore/shopapspress/pages/apps.aspx

This interactive reference tool is set up for fast identification of tomato problems, based on symptoms of root, leaf, stem, and fruit. The goal of the app is to move you quickly through the most difficult part of dealing with a sick plant: what’s wrong and what is causing it. The app includes an index of nearly 30 diseases and insect disorders, an extensive photo gallery of the most common problems, and a list of diseases according to their characteristics. Tomato MD does more than just help with identification; management tips are included, too.

For more help in identifying what’s wrong, take a look at my website (above), then read our online fact sheets about dealing with tomato problems, which can be found here: http://ccesuffolk.org/gardening/horticulture-factsheets/vegetable-diseases. If you’re still stumped, call our Horticulture Diagnostic Lab at our hot line at 631-727-4126 from 9 a.m. to noon, Monday through Friday, where Alice Raimondo and Sandra Vultaggio, our Horticulture Consultants, are available to answer all your horticulture questions.

Dr. Meg McGrath is Associate Professor at Cornell University’s Long Island Horticulture Research and Extension Center in Riverhead, New York, where she conducts research and extension activities to help farmers manage diseases.

Best Way to Water Your Lawn

Question: I water my lawn every day, but it still looks like it’s drying out and turning brown. What is the correct way to water?

Answer: Usually there’s plenty of rain on Long Island during April, May, and sometimes well into June, but this year we weren’t so lucky. And summer rainfall has not been forthcoming. Most lawns need an inch or so of water each week to stay green, which is approximately how much moisture they lose weekly through evapotranspiration.

I suspect you are running your sprinklers for twenty minutes or so daily. Unfortunately, this means you are wasting lots of water and not helping your lawn. A brief daily shower only moistens the grass blades and doesn’t deliver enough water to the turf roots, which is why your lawn is going into drought stress.

Daily watering resulted in the drought-stressed lawn at the top of this picture. Compare it with the next-door neighbor's healthy lawn at the bottom, which receives one-inch of water just once a week.

Daily watering led to the drought-stressed lawn at the top of this picture. Below it, the next-door neighbor’s green grass receives only an inch of water once a week.

The best way to water your lawn with an inch of water is to soak it just once a week, which may take several hours depending on your water pressure and sprinkler heads. You can determine how long your system takes to supply one inch of water to your lawn by setting several empty tuna cans inside the spray pattern of your sprinklers and watching until they fill up to one inch; or you could buy a few inexpensive plastic rain gauges.

Late summer storms often supply ample amounts of water. As summer winds down, keep track of how much rainfall you get; then adjust your irrigation accordingly. Learn more about correct watering practices by looking at Suffolk County’s Healthy Lawns, Clean Water website, which discusses this in greater detail: http://healthylawns.suffolkcountyny.gov/lawn/watering.htm

Alice Raimondo is Horticulture Consultant for CCE Suffolk. She can be reached at aw242@cornell.edu or 631-727-77850 x335.