Category Archives: Lawn care

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.

Hairy Bittercress: A Mustard with Momentum!

What is that battalion of tiny white flowers appearing all over the lawn so early in the season? The one with the lacy green doily at the base, and sword-like seed pods, and the maroon cast? Gasp! It is the hairy bittercress!!! Now before you call out the weed police or haul out the weed killer, consider this: Did you know that hairy bittercress is a very important early source of pollen and nectar for bumblebees? As such it should be conserved along with (double gasp!!) dandelions.

Bittercress plant with flowers and seed pods just starting to develop. Photo by Andrew Senesac.

Bittercress plant with flowers and seed pods just starting to develop. Photo by Andrew Senesac.

Now that we have that out of the way, let’s settle down to learn a bit about hairy bittercress habits and some do’s and don’ts for dealing with an outbreak of it.  This weed grows best in damp, recently disturbed soil.  Be wary of digging it up in spring because this practice opens holes for crabgrass to emerge.  A winter or summer annual, different varieties of bittercress have different heights. A key characteristic is its basal rosette, a “doily” like circular array of leaves at the bottom of the plant. The weed will germinate in fall or winter but grows best during warm weather. It quickly invades thin turf especially where there is good soil moisture. Shade encourages its growth, and it may escape mowing by low growth. Post-emergence control for it generally includes using 2, 3, or 4-way herbicide; treatment during its basal rosette stage is best before it throws up a flower stalk and begins to produce seed.

Hairy bittercress thrives in sandy, organic soil. Wash your nursery containers rather than leaving them around with soil clinging to them—dirty containers harbor its seed, with six times more seedlings emerging from dirty containers than from those that are rinsed. Also, containers lying around tend to breed Asian tiger mosquitoes! Now you have two good reasons to clean up your containers.

Hairy bittercress has exploding seed pods but little germination of fresh seed. Instead, its seed ripens with high temperatures. The higher the temperature, the greater the temperature range at which subsequent growth will take place. Hairy bittercress can germinate from April through November; however, autumn is its main period of emergence. Peak flush of germination is in November and December, but this varies from year to year. We don’t notice these plants until spring when they throw up flowers and seedheads, seeming to mock us from our winter-bound vantage points as we eyeball our winter weary lawns. Just remember: Each hairy bittercress you allow to flower helps support our vital pollinators when they really need the nectar and pollen these plants provide. So help out a bumblebee, and leave hairy bittercress alone if you can; it’s an annual so it’s gonna die anyway….

Dr. Tamson Yeh is CCE Suffolk Turf Use and Land Management Specialist. She can be reached at tsy3@cornell.edu or 631-727-7850 x240.

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.

Vole Control: Time to Be Vigilant

Have you had trouble with voles over the past few years? Our harsh, snowy winters have created ideal environments for voles to thrive. Voles can wreak winter-time havoc on young trees, shrubs, perennials, and your lawn. Fall and early winter are the best times to implement controls for mitigating the damage these small creatures can do.

The meadow vole is common on Long Island. Photo by John Mose.

The meadow vole is common on Long Island. Photo by John Mose.

A vole is a small rodent resembling a mouse but with a stouter body, a shorter, hairy tail, a slightly rounder head, and smaller ears and eyes. Two species of voles reside in New York State: the meadow vole (Microtus pennsylvanicus) and the pine vole (Microtus pinetorum). You can read descriptions of each and more about their biology and habits in this Voles fact sheet on our website.

Hidden from predators, voles happily travel under snow cover, feasting on blades of grass and the bark of trees and shrubs. Voles like to gnaw around the circumference of woody plants until they are completely girdled. Once the snow melts, the damage is clear: long, 2-inch wide runways of beaten down, damaged turf grass, and woody plants that suddenly die after the first flush of spring growth.

Here are a few ways to deter voles and protect your plants by reducing their favorite winter habitats:

  • Clean up piles of leaves and branches.
  • Remove grass and weeds from around trees and shrubs (this area should be clear of grass anyway to prevent injury from mowers or line trimmers).
  • Bare soil is ideal within the first few inches of ground that surround plant bark. At most, put only a very light layer of mulch there.
  • Don’t mulch excessively in flower beds as this will favor vole activity.
  • Before it snows, install fine-gauge hardware cloth around tree trunks to prevent voles from chewing young wood.
  • Make your last lawn mow of the year slightly lower than normal to discourage voles from creating surface trails through longer grass. Lowering the mower deck to 3” works well.

If you find you need to control the population of voles on your property, try using snap-back mouse traps placed in boxes with holes on either side; this is one of the more effective control methods. Populations of voles tends to be highest in the fall and before our first snowfall, so act now!

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.

Sample Soil Now for Healthier Landscapes Next Year

Spring is by far the busiest time for gardeners. Between selecting plants, starting seeds, and preparing beds, we often forget about what’s basic: the soil. Suddenly remembering, in April gardeners furiously submit handfuls of soil to our Horticulture Diagnostic Lab for testing, expecting immediate turnaround, and then realize, “What!? It takes how long for limestone to change the pH of my soil!?”

This is why autumn is the perfect time to start preparing your gardens for the growing season ahead. Submitting soil samples to us now allows you enough time to collect your samples properly, understand the test results, and if you need to make amendments to the soil, time for them to activate before next spring.

Using a soil auger makes collecting samples easy, but a trowel will work just as well.

Using a soil auger, shown above, makes collecting samples easy, but a trowel will work just as well. Photo by Robin Simmen.

Maintaining the proper soil pH is just as important for maximum crop yields as fertilizing, watering, and pest control. The decision to add lime to raise the soil pH and the amount to apply must be based on a soil pH test and the crop species to be grown. Do not guess. Some plants, like rhododendrons, azaleas, and blueberries as well as other members of the Ericaceae family grow best in acid soil (pH 5.0). Most vegetable garden plants grow best in soil with a pH in the 6.2 range. The recommended range for a lawn is between 6.0 and 7.0.

Instructions for taking a soil sample

First determine how many samples to take. Different gardens/beds, lawns, areas with different soil types, places where such amendments as limestone were added, areas with plants having different pH requirements, and good/bad areas should be sampled separately as described below:

  • In gardens or areas planned for new plantings where the soil will be turned under or rototilled, individual samples should be taken from the upper 6 to 8 inches of soil.
  • In established plantings or lawns where the soil won’t be turned under, individual samples should be taken from the upper 3 inches of soil.
  • Each soil sample should be comprised of 5 to 10 individual samples obtained by walking back and forth diagonally across the area to be sampled.
  • Use a trowel to dig a small hole to the desired depth. Remove a slice of soil from the entire side of the hole and place this in a clean plastic container. Repeat this procedure at each of your 5 to 10 random spots, and place the soil from these spots in the same container, discarding any stones, grass, or other debris.
  • Next, remove two 8-ounce cupfuls of the soil in this container and place them in a plastic bag. Secure the bag. This is your soil sample for that area. Mark the outside of the bag with an identification (i.e. #1, #2, or “A”, “B”, or “East”, “West”). Keep the identification simple.
  • Repeat this entire procedure for each additional garden, landscape bed, and/or lawn area you wanted tested.

You can find soil testing submission forms to accompany your samples on our website at http://ccesuffolk.org/agriculture/horticulture-diagnostic-labs. The cost of a soil pH test is $5 per sample; if you submit five or more samples, they cost $3.50 each. Mail or drop off your samples at 423 Griffing Avenue, Riverhead, NY 11901. Our office hours are Monday through Friday 8:30 a.m. to 4:30 p.m.

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.

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.