Category Archives: Invasive plants

Summer Session for the Advanced Training for LI Gardeners is Back!

Have you ever wanted to take the “Master Gardener” course but cannot commit to the lengthy training or volunteer work?

Our popular online course is back- CCE Suffolk will again offer a 9-week online course for our gardening community, based on the horticultural research and experience of Cornell University specialists and experts in their field.

The Advanced Training for LI Gardeners (ATLIG) offers many of the same horticultural topics included in the Master Gardener Volunteer training, including botany for gardeners, soils, beneficial insects, composting, vegetable and fruit gardening, lawn care, plant diseases, climate resilient gardening, managing wildlife, pests and much more.

You can download more information and the Registration Form here: ATLIG Summer 2019 Registration

The online course will begin on June 24 and end August 23, 2019. There are no sessions to attend in person.

Contact Donna Alese Cooke at for more information. Limited space is available.

It’s Not too Late to Join our Spring Gardening School!


Join us for our full day of Gardening Workshops at Suffolk County’s annual Spring Gardening School on Saturday, April 13, 2019. Organized by Master Gardener Volunteers for the last 37 years, this beloved event kicks off the growing season for hundreds of gardeners who gather together for a day of learning and fun.

This year’s Spring Gardening School will be held at the Riverhead Middle School in Riverhead, NY. All classes are taught by Master Gardener Volunteers, Cornell Cooperative Extension Educators and local experts.

Download the registration form at×11.pdf?1549037029

There is still room in these sessions:

1D- Food Security: Issues & Potential Solution

2C- What’s Wrong with This Picture?

2D-Invasive Woodland Weeds: Top Ten Problems on Long Island

3B-Gardening with Chickens

4A- Indoor Plants

4B- For the Beginner–Gardening 101

Extended Sessions

EXAM 1: Design & Install Drip Irrigation

EXAM 2: Nature’s Colors in Your Hands

EXAM 3: Field of Poppies Botanical Art

EXAM 5: Organic Landscape Maintenance

EXPM 1: Floral Design for Beginners & Intermediates

EXPM 2: Make & Bake Herb Bread & Butter,

EXPM 3: Field of Poppies Botanical Art

EXPM 4: Pruning Roses and Hydrangeas: No More Flowerless Plants!

Classes fill quickly! Download the brochure here which has the registration form to mail back to us. We look forward to seeing you there!

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 or 631-727-3595.