Tag Archives: Hurricane Sandy

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.

Managing Mile-a-Minute Weed

Mile-a-minute weed, Persicaria perfoliata, is a highly invasive annual vine appearing on the East End and other parts of Long Island. Its triangular shaped leaves are very distinctive and easy to identify. The weed is invading natural areas, residential yards, and landscapes. It thrives in areas of partial shade but can survive in full sun; mile-a-minute can potentially invade and establish itself in many environments. It is often found on the edges of residential properties near woods and sometimes on the periphery of field nurseries. It has also been spotted growing on the beach in different locations.

This site was infested by mile-a-minute seed that Hurricane Sandy carried  here.

This site was infested by mile-a-minute weed carried to Long Island by Hurricane Sandy.

Mile-a-minute weed has several commonly used nicknames: Asiatic tearthumb, climbing tearthumb, and devil’s tail. These monikers describe the sharp downward-curved prickles or spines that grow on the vine’s stem and petioles. Any attempts to hand pull this weed without wearing heavy leather gloves quickly illustrates why tearthumb is one of its names. Its spines act like claws that enable the vine to attach easily to nearby vegetation. This adaptation allows it to grow straight up towards open areas of tree or shrub canopy without having to waste energy by twining like other plants.

This rapid upward growth is the reason for its other common name: mile-a-minute. It takes advantage of most of the growing season on Long Island to produce multi-branched, thin-stemmed vines that are loaded with attractive blue fruit. When ripe, individual shiny black seeds are contained within a fleshy fruit that is very easily knocked off the vine. The seeds spread to new sites via migrating birds and other wildlife. Because the ripened fruits are so easily dislodged, hand pulling the vines after fruits begin to form in late July is not recommended. Leaving the vine alone in late summer and fall is a better option than trying to remove it from a site.

Immature and ripe mile-a-minute fruit in late July are easily dislodged.

Immature and ripe mile-a-minute fruit in late July are easily dislodged.

Recent research has shown that even immature green fruits can eventually mature off the vine to produce viable seeds for re-infestation. That leaves the months of May, June, and most of July to use cultural practices like hand pulling, string trimming, and mowing to suppress/control this weed. Because it has an annual life cycle, removing young plants has a very reasonable chance of significantly reducing the population. If mature plants are hand pulled after late July, the vines should not be placed directly into compost piles or other areas where the viable seeds can remain a threat. The pulled vines should be put under a tarp or landscape fabric until the fruit is no longer viable.

In addition to cultural practices, the NYSDEC recently approved a 2(ee) recommendation for the herbicide glyphosate (Accord XRT II, EPA Reg. No. 62719-556) for post-emergent control of mile-a-minute vine in non-crop areas. Because glyphosate is non-selective, it should be used only in areas where no desirable vegetation could be exposed to drift. However, in such areas where many seedlings are growing, using this herbicide can be an efficient way to control young plants.

Beneficial weevils eat the leaves of mile-a-minute weed.

Beneficial weevils eat the leaves of mile-a-minute weed.

Since 2004, a biological control has been released to help suppress this weed. Developed by Dr. Judy Hough-Goldstein at the University of Delaware, a small weevil, Rhinomomitus latipes, was found to feed on the leaves and stem of mile-a-minute without eating other desirable plants. On eastern Long Island the weevil has been evaluated since 2012 through controlled releases of it in areas infested with mile-a-minute. The weevil has also found its way here from surrounding states that use it to manage this weed. The weevil begins to feed on mile-a-minute leaves in early spring and continues all season. It lays eggs in the plant stem, which the subsequent larvae weaken as they develop and begin to feed. The adults overwinter in the leaf litter at the ground surface.

Unfortunately, there is a lot more weed than weevil, so we need to continue to increase the weevil population here. Funding cuts have meant CCE Suffolk must now purchase the formerly free weevils. We are hoping to develop a program that would not depend on re-introduction of the weevil every year. These beneficial weevils may play an important role in helping eradicate this scourge from our landscape before it becomes better established on Long Island.

Andrew Senesac is Weed Science Specialist for CCE Suffolk. He can be reached at afs2@cornell.edu or 631-727-3595.