Tag Archives: Horticulture Diagnostic Lab

The Horticulture Diagnostic Lab Can Help!

Do you have questions about gardening? Need a soil test? Want help identifying plant pests or diseases? Wonder what kind of insect or tick you’ve found? The Cornell Cooperative Extension of Suffolk County Horticulture Diagnostic Lab can help! Our Horticulture Consultants can assist with plant problem diagnosis, pest identification, and general gardening and landscaping information. You can reach them through Call-In Help Lines, or stop by in person. There are two locations in Suffolk County:

Cornell Cooperative Extension
Extension Education Center
423 Griffing Ave, Riverhead, NY 11901
Open year round, Monday-Friday, 8:30am-4:30pm
Call-in help line: 631-727-4126; 9:00am-12:00pm

Bayard Cutting Arboretum
Montauk Highway, Great River, NY 11739
Open from April 27-October, Thursdays and Fridays only, 10:00am to 4:30pm
Call-in help line: 631-581-4223; 8:45am-11:45am and 1:00pm-4:00pm

Click here for more information about the Horticulture Diagnostic Labs.

You can also find many great resources here: http://ccesuffolk.org/gardening.

Also, check out this article from the Northforker on the lab!

Register for Spring Gardening School

Join us for Suffolk County’s annual Spring Gardening School on Saturday, April 22, 2017, 8:30 a.m. to 4:00 p.m. Organized by Master Gardener Volunteers for the last 35 years, this beloved event kicks off the growing season for hundreds of gardeners who gather together for a day of learning and fun.

Spring Gardening School 2017 will be held at Longwood Senior High School in Middle Island, NY. All classes are taught by Master Gardener Volunteers and Cornell Cooperative Extension Educators. The day consists of workshops held during three sessions and offers classes for beginners to advanced gardeners. This year a keynote address on “Long Island Native Plants and Pollinators” will be presented by Polly Weigand, Executive Director of the Long Island Native Plant Initiative. You can sign up for such classes as Gardening with Chickens, Design & Install Drip Irrigation, How to Attract and Enjoy the Ruby-Throated Hummingbird, Low-Water Gardening, Seed Starting Demystified, and many, many more.

The fee to attend is $65 per person ($60 early bird, before March 1st), which includes free soil pH testing, a Long Island Gardening Calendar, a plant diagnostic clinic, gardening exhibits, and an early plant sale from some of the finest nurseries on Long Island; continental breakfast, delicious boxed lunch, raffles, and door prizes. Preregistration is mandatory; first come is first served. Here is a registration form with a full schedule of classes and their descriptions for you to download and send to us. We look forward to seeing you there!

Tomato and Potato Late Blight: What to do NOW!

Late blight is arguably the worst problem that can appear in a vegetable garden! Its highly contagious and very destructive nature means everyone growing susceptible tomato and potato plants – gardeners and farmers alike – needs to take action to prevent late blight from occurring and needs to respond quickly when it appears. The major epidemics of this disease on Long Island in 2009 and 2011 are thought to have started with just a few infected plants.

Sungold cherry tomato can be devastated by late blight, as it was here in my garden in 2013.

SunGold cherry tomato can be devastated by late blight, as it was here in my garden in 2013. Photo by Meg McGrath.

Early Season Action Steps to Prevent Late Blight:

  • Select varieties that have resistance to late blight. For example, the popular SunGold cherry tomato is susceptible to it; Jasper cherry tomato is not. Information about tomato varieties can be found at http://www.extension.org/pages/72678/late-blight-management-in-tomato-with-resistant-varieties#.VRNfGkZwfsM
  • Plant certified potato seed. Do not plant potatoes from last year’s garden or from the grocery store. There is a higher probability for the late blight pathogen (Phytophthora infestans) to be in “table-stock” potatoes.
  • Destroy any potato plants that grow as “volunteers” in compost piles or in the garden from potatoes not harvested last year.
  • Inspect tomato seedlings carefully for symptoms before purchasing them. The pathogen as it exists in the United States is not known to survive in tomato “true” seed and then infect the seedlings, so if you grow your own seedlings, late blight is not a concern until they are planted. Seedlings become infected by growing near other affected plants.
  • Become knowledgeable about the different symptoms of late blight and its imitators. I have posted photographs of this at http://livegpath.cals.cornell.edu/gallery/tomato/tomato-late-blight/.
  • Monitor the occurrence of late blight in the United States at usablight.org. You can sign up on that website to get an alert by text or e-mail when a report has been logged nearby, so you can be one of the first to know when late blight has been found on Long Island.
  • Inspect your tomato and potato plants for symptoms at least once weekly.
Inspect tomato plant leaves for symptoms of late blight, such as the discoloration you see here. Photo by Meg McGrath.

Inspect tomato plant leaves for early symptoms of late blight, such as the discoloration shown here. And then act fast! Photo by Meg McGrath.

What to do when late blight symptoms are found: Immediately call our Horticulture Diagnostic Lab at our hot line at 631-727-4126 from 9 a.m. to noon, Monday through Friday. Alice Raimondo and Sandra Vultaggio, our Horticulture Consultants, can help determine whether you do, indeed, have late blight, and answer questions about proper handling of an outbreak.

Best management steps for dealing with disease are based on knowledge of the pathogen’s biology and life cycle. The late blight pathogen in the United States is not known to reproduce sexually, as it does elsewhere in the world including in parts of Europe. Where it does reproduce sexually, it produces a type of spore (oospore) that enables the pathogen to survive in true seed and in soil; consequently, rotation is an important management step in Europe, but this is not necessary for controlling late blight in the United States.

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.

Register Now for Spring Gardening School

Join us for Suffolk County’s annual Spring Gardening School on Saturday, April 16, 2016, 8:30 a.m to 4:00 p.m. Organized by Master Gardener Volunteers for the last 34 years, this beloved event kicks off the growing season for hundreds of gardeners who gather together for a day of learning and fun.

2016 poster Spring Gardening School 2016 will be held at Patchogue-Medford High School in Medford, NY. All classes are taught by Master Gardener Volunteers and Cornell Cooperative Extension Educators. The day consists of workshops held during three sessions and offers classes for beginners to advanced gardeners. New this year is a keynote session with an address on Grow More with Less: Sustainable Gardening Methods by Vincent Simeone, Director of Planting Fields Arboretum. You can sign up for such classes as Choosing the Right Trees, Gardening with Chickens, Design & Install Drip Irrigation, Pruning Roses & Hydrangeas, Seed Starting Demystified, and many, many more.

The fee to attend is $65 per person, which includes free soil pH testing, a Long Island Gardening Calendar, a plant diagnostic clinic, gardening exhibits, and an early plant sale from some of the finest nurseries on Long Island; continental breakfast, delicious boxed lunch, raffles, and door prizes. Preregistration is mandatory; first come is first served. Here is a registration form with a full schedule of classes and their descriptions for you to download and send to us. We look forward to seeing you there!

Robin Simmen is Community Horticulture Specialist for CCE Suffolk. She can be reached at rls63@cornell.edu or at 631-727-7850 x215.

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.

Caring for Holiday Plants in the New Year

Now that the holidays are behind us, decisions must be made regarding the plants we used to decorate our homes or received as gifts. Poinsettias, amaryllis, Christmas cactus, and cyclamen are traditional holiday flowers. Some are quite easy to keep as houseplants and will flower again if given the right conditions. Others are a bit more challenging; maybe it’s best to toss them onto the compost pile after flowering. You be the judge.

Christmas cacti are easy to grow and force into flower year after year. Photo c Alice Raimondo.

Christmas cacti are easy to grow and force into flower year after year. Photo © Alice Raimondo.

Perhaps the simplest to care for is the Christmas cactus. Many of these cacti are actually hybrids, called Zygocactus, and are not true Christmas cacti which belongs to another genus. In any case, the Christmas cactus can be forced to flower anytime from Thanksgiving through Christmas, provided that starting in September you withhold water from it and it experiences 13-hour nights and cool temperatures in the 55-60 degree range. This is fairly easy to accomplish as this is what normally happens outdoors.

Begin by putting the plant outside in late May in a shaded location, water it once a week or so, and fertilize it every other week with a water-soluble fertilizer. Move your Christmas cactus back into the house in late October when the threat of frost occurs. By then these plants are usually full of flower buds. To prevent bud drop, keep your plant in a cool room until the first flowers open; after that you may place it anywhere to enjoy. Once it has finished flowering, water your Christmas cactus lightly and give it bright but indirect sun. Be careful not to over water as it will rot if watered too heavily.

Another really easy plant to care for is the amaryllis. After it flowers, simply cut off the flowering stalk when it yellows, and keep the bulb watered and in a sunny or bright location. Amaryllis leaves are produced either after or along with its flowers. These leaves need to stay healthy and growing throughout the winter, spring, and summer; they nourish the bulb so it can bloom again. Like the Christmas cactus, amaryllis enjoys summer vacation outdoors in a sunny location. Water your plant a few times a week as needed, and fertilize it every other week or use a slow release fertilizer on the soil surface.

In September it is time to stop watering your amaryllis. I find the easiest way to do this is to move the plant into a garage and simply forget about it. This treatment forces the bulb into dormancy, a rest period during which the leaves dry up. After about ten weeks, the pot can be brought indoors and placed in a bright location. Give it a light drink of water and then hold off watering again until you see the flower bud start to emerge from the bulb. Amaryllis bulbs can be kept alive for years this way, and their flowers are very rewarding.

Poinsettias and cyclamen are a bit more challenging, so typically I don’t keep them from year to year. Poinsettias often are host to whiteflies, and cyclamen often suffer from corm rot or weak growth. Rarely do either of these plants put on the same flower show if saved as they do when they were originally purchased. Having worked at a greenhouse for several years, I can honestly say that maintaining healthy poinsettias and cyclamen is best left to the grower unless you have lots of space in your home and lots of time on your hands. That said, care information for both plants as well as for Christmas cactus and amaryllis can be found in the following fact sheets: Care of Holiday Plants and Forcing Bulbs for Indoor Bloom.

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

Winter Care of Tropical Houseplants

During the chilly dark days of winter, our houseplants and overwintering tropicals remind us that green life still exists, which gets us crazy gardeners through what can be a depressing time of year. Living with indoor plants is a subject near and dear to my heart, and I have lots of experience to pass along to you. I thought I’d start by talking about how to overwinter the large tropical plants that many people buy in spring, such as hibiscus, elephant ears, cannas, lantana, brugmansia, and mandevilla, and provide some sound advice for houseplant care so you may fully enjoy your indoor garden all winter.

Bird of paradise makes a cheerful indoor winter companion. Photo c Alice Raimondo.

Bird of paradise makes a cheerful indoor companion. Photo © Alice Raimondo.

As I write this, it is a relatively mild mid-December day but far too cold outdoors for tender tropicals. Summer provided all the things they needed to survive: sunlight, humidity, water, and lots of air circulation. How can we give them what they need indoors for the next several months before moving them outside once more? I’m sure I’m not the only one whose tropical plant’s leaves all turned yellow and dropped off a few days after bringing it indoors in the fall. A common mistake is waiting too long to bring these plants inside; it’s better to bring them indoors in late August before nighttime temperature start to drop. This is especially true for hibiscus or mandevilla; however, some leaf drop with them should be expected. Indoor environments have low humidity, particularly during winter when the heat comes on frequently, so plants drop leaves to reduce water loss.

Fear not, your plants will adjust, provided you site them properly. If placed near sunny south-facing windows and away from radiators, hibiscus plants will perform quite well as houseplants for a while, at least until whiteflies or aphids likely arrive. Mandevilla can be a bit trickier as a houseplant, often losing all of its leaves during the winter and going semi-dormant. Be very careful how you water them then; I have killed several, I fear, from overwatering alone. Mandevilla can also be a magnet for scale and mealybugs in the home, so if other houseplants are nearby, beware! Lantana is best not brought indoors unless you have a sunny, dry, cool location where it can grow.

Much of my garage has nothing to do with cars during winter. Photo c Alice Raimondo.

My garage is home to dozens of  plants during winter. Photo © Alice Raimondo.

Elephant ear tubers and canna fleshy rhizomes can be stored dormant in an unheated location with no light, provided it gets no colder than the upper 40s. If your cannas and elephant ears were dug from the ground after the first frost, they will overwinter very well in paper bags or in cardboard boxes in temperatures in the low 50s. Another plant that stores equally well in garages where it will go dormant is brugmansia. No need to water it but a few times, very lightly, throughout the winter so its root ball doesn’t dry out completely. Keep brugmansia cool at temperatures in the upper 40’s to near 50 degrees; any warmer, and it will break dormancy and begin to grow. You can store this large woody tropical indoors from year to year until the plant is too big to fit in the garage. Even then, you can lay them down in the garage after they’ve grown too tall; these plants are indestructible! I currently have flowers on mine, as they haven’t yet gone to sleep yet for the winter.

Phalenopsis orchids love humidity. Photo c Alice Raimondo.

Phalaenopsis orchids do fine with enough humidity. Photo © Alice Raimondo.

If you aren’t brave enough to try overwintering these large tropical beauties, which are often sold as annuals, there are many houseplants to grow that are just smaller counterparts of their larger cousins. Peace lily, African violet, phalaenopsis orchids, and many foliage plants will chase your winter blues away as you garden indoors. Or perhaps you have space to grow large palms or bird of paradise. Plan your indoor garden as you do your yard: consider sun exposure, water requirements, and home temperature. One word of advice: water. Overwatering is the most common mistake when it comes to houseplants, so be careful to not kill your plants with too much love. Drooping or yellowing leaves is a symptom of too little water, but it’s also a symptom of watering too frequently.

The Horticulture Diagnostic Lab often receives calls regarding sick houseplants during the winter. If you have questions about caring for specific plants, call us at the Horticulture Information line (631)727-4126. In the meantime enjoy your little bit of the tropics indoors, and dream about spring.

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

Simple Ways to Protect Plants Now from Winter Injury

Weather conditions for the past two years have favored all sorts of winter injury to landscapes; this year may be no different. Droughty summers and autumns followed by long winters filled with wide temperature fluctuations can wreak havoc with plants and soil. But fear not! Here are some simple ways to help your plants come out of this winter unscathed.

Needled and broad-leaved evergreens such as arborvitaes, cherry laurels, and rhododendrons often suffer severe winter discoloration, browning, and even death from several causes. Winter sun (think southern exposure) combined with wind can create excessive transpiration, or foliage loss of water, at the same time as soils are frozen so plant roots can’t replace the lost water. This can be particularly disastrous for late season plantings in October, November, and December if plants aren’t well watered and if roots haven’t had time to grow out of the existing root ball. That’s why September is best for fall planting, not November!

Bright sunny winter days when leaves warm up may trigger cellular activities such as photosynthesis and cellular respiration. This break from dormancy can result in severe plant injury when nighttime temperatures drop abruptly, for example from the 40’s down to the teens in the course of a day or so. These conditions also bleach evergreen foliage, for example on boxwood, when chlorophyll is destroyed in plant tissue and then not rebuilt due to low temperatures. Late pruning in October, which generates new late season growth, is another cause of injury or death when cold temperatures occur. This sort of injury also occurs in May when light frosts settle into low areas during the time of tender new growth.

A piece of burlap posted in front of these inkberry plants will protect them from winter sun and wind. Photo c Alice Raimondo.

A piece of burlap posted in front of these inkberry plants will protect them from winter sun and wind. Photo © Alice Raimondo.

Protecting your evergreens from these sorts of winter injury is easily done. First and foremost, consider where you locate plants. South, southwest, and windy sites may not be the best places for evergreens. For plants in such sensitive conditions and for those that are less winter hardy, consider constructing a burlap barrier on the southern and/or windy side of the plant to shade it from the harsh winter sun and keep temperatures consistent, thereby reducing the injuries described above. Place the screen in front of the plant; don’t wrap it completely with burlap.

Water loss is by far the most important and misunderstood aspect of winter injury. Established plants shouldn’t be over watered in September as this will slow down their hardening off process, but they need to be well watered through October and into November if there isn’t regular, measurable rainfall. This regular watering in the autumn is particularly important for trees and shrubs in the ground for less than three or four years. Anti-desiccant and/or anti-transpirant sprays offer protection that is limited at best, but these can be applied in conjunction with correct watering and sun/wind screens.

Sunscald of thin-barked trees (cherry, maple, linden, and plum) is another common winter injury. Sunscald creates sunken, cracked, or dried areas on the trunk, which are elongate in shape. Young, newly planted trees are particularly sensitive to this damage as their bark is not well developed. Shading tree trunks from the harsh southern winter sun helps keep their living cambium tissue dormant, protecting it from freezing temperatures following a thaw. On young and newly transplanted trees, consider not pruning their lower branches for a season or two to help shade their trunks.

Cold that follows relatively warm temperatures is common on Long Island and often kills or damages less winter-hardy flower buds such as those of Hydrangea macrophylla. This is why many of us haven’t seen flowers on these beloved plants for the past two winters! The big-leafed a.k.a. mophead hydrangea has a bad habit of breaking dormancy as early as late February in sunny locations. Constructing a sun screen similar to that suggested for evergreens may help reduce this sort of cold temperature injury.

Our winters often bring heavy wet snows and ice storms that cause significant injury to plants from extra weight bending and breaking their branches. Protect plants in dangerous locations, such as where snow falls off roofs or where drifting and blowing snows accumulate, by tying or wrapping them to hold them together. If possible, carefully remove heavy, wet snows from plants before the snow freezes solid, encasing the plant in heavy ice.

For those of us with new landscapes, a real concern is frost heaving. Our soils tend to freeze and thaw and then freeze and thaw again, sometimes popping smaller shrubs and perennials right out of the ground. This is a big problem for those fall-sale beauties you may have planted in October or that late season perennial dividing and replanting you did the first week of November when it was 70 degrees. You can protect your plants by insulating the ground around them with mulch. Apply a layer of mulch three-inches thick, being careful to not bury the crowns or stems of the plants. Wait until the ground freezes before applying mulch to keep the ground frozen and discourage rodent activity. Consistent soil temperature will reduce the likelihood of frost heaving.

For more information, read the fact sheet on our website about Winter Injury. Hopefully, some of these simple tips will help your plants survive the winter and thrive come next spring. Putting in a little extra time now will reduce spring cleanup of winter-injured plants that need to be pruned or replaced. There’s still plenty of time to prep plants for the ravages of winter!

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

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.

Late Blight on Long Island – Did We Dodge the Bullet?

While gardeners and farmers elsewhere, including upstate New York, have been battling late blight in 2015, so far it hasn’t been found on Long Island! At least, not yet . . . This is the first year since 2008 that this highly contagious and very destructive disease of tomatoes and potatoes hasn’t been observed here in spring and summer. Its absence means that on Long Island, we are successfully managing plant sources of the late-blight pathogen, Phytophthora infestans, in three ways by:

  • not planting infected potato tubers to grow new crops
  • not leaving infected potato tubers from previous crops in the ground or putting them in cull or compost piles
  • not planting infected tomato seedlings
We all dread seeing these symptoms of late blight appear on our tomatoes!

We all dread seeing these symptoms of late blight appear on our tomatoes! Photo by Meg McGrath.

But one source of late blight remains on the scene and continues to be a threat until frost: spores blown long distances by wind. Typically spores of Phytophthora infestans blow no more than about 30 miles, but their farther wind dispersal is possible. A Long Island outbreak of late blight in August 2007 was, I think, the result of a storm carrying spores here from Lancaster, Pennsylvania. And in October of 2002 and 2008, late blight made its first appearance of the year on Long Island. There have been reports recently of late blight in New Jersey, so we’re not out of the woods yet.

Here is when late blight was first observed on Long Island in recent years:

  • October 3, 2002
  • July 5, 2006
  • Aug 26, 2007
  • October 3, 2008
  • June 23, 2009
  • June 18, 2010
  • June 24, 2011
  • May 29, 2012
  • July 25, 2013
  • June 20, 2014

Do you want to know where late blight has been reported in the United States this year? Check out www.usablight.org. Anyone can sign up on this website to get an alert by text or e-mail when a report has been logged nearby, so you can be one of the first to know when late blight has been found on Long Island. But realize your plants could be the first affected; therefore, signing up for alerts is not a substitution for looking for symptoms at least once a week. My own garden plants were part of the August 2007 outbreak!

Considering the potential impact of late blight, everyone who grows tomatoes and potatoes is responsible for inspecting their plants for late blight, reporting it when seen, and managing affected plants to minimize its spread. Photographs and information about late blight are posted on my website at: http://livegpath.cals.cornell.edu/gallery/tomato/tomato-late-blight/

If you see symptoms you think might be late blight (rather than one of its imitators, also shown on my website) 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, can help determine whether you do, indeed, have late blight, even this late in the year.

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.