Laura Lennihan’s grandparents must have been true romantics. Fifty-plus years ago, they planted lilac bushes, which symbolize first love, around their Vineyard Haven home.

Every May, Laura enjoys the fruits of their labor when these bushes blush — that is, bloom profusely and provide a visual and odiferous reminder of them and their affection. However, this July Laura’s sister noticed that the historically healthy shrubs had some browning of the leaves. Fast forward to September and Laura was shocked to return to see that these beloved bushes appeared just about dead and denuded of leaves. Those that remained seemed diseased.

She got busy right away to figure out what these clearly suffering species were afflicted with and found a few organisms on which to register responsibility.

A bacterium could be blamed. After conferring with UMass Center for Food, Agriculture and the Environment, Laura found one potential cantankerous culprit: Pseudomonas syringae. This bacterium is generally present in the environment and can harmlessly live as an epiphyte on lilac and other plants. It can be found in the soil or detritus and can be spread by wind, insects, splashing rain and even on garden tools.

However, once the bacterium gets into the plant through a wound or weak spot, it becomes a destructive force. Also called bacterial blight or shoot or blossom blight, Pseudomonas bacterium will target plants already stressed by drought, lack of nutrients or other physical injuries.

First the lilac leaves will show damage around the margins and along the central vein. Twigs can turn black and wilt from the tips back to the stem and the leaves will get brown spots and tissue malformation. New infections can emerge in the spring with wet weather and, for those weakened shrubs, very quickly infiltrate and make their damaging mark.

Laura also reached out to officials at Polly Hill Arboretum and they are also investigating, noting that bacterial leaf blight has been rampant on-Island this year. At the arboretum, staff cut their lilacs way back to hope for spring rejuvenation. Other lilacs in Laura’s neighborhood were similarly afflicted.

Most sources confirm that this blight will not usually kill lilacs unless the bacterial infiltration goes on for multiple years. The recommended solution is to remove the affected leaves and twigs and dispose of them properly so as not to spread the bacteria to other plants. That is the good news.

The bad news is that there were other concerns. Additional lilac issues include a similarly named fungus called Pseudocercospora and also another fungal disease called verticillium wilt.  More potential pillagers such as lilac stem borer, and powdery and downy mildew can be a catastrophic combination that may be too much for the plants to bear. There are so many predators for lilac to fear!

Laura noted that UMass can conclusively diagnose your problem and shared this useful information to help correctly identify these and other garden problems. Their website states: “The UMass Plant Diagnostic Laboratory is accepting plant disease, insect pest, and invasive plant/weed samples. By mail is preferred. For instructions on sample submission and to access the submission form, go to https://ag.umass.edu/services/plant-diagnostics-laboratory. The diagnostic fee for tree/shrub disease

It doesn’t seem too much to pay for peace of mind. Whatever the condition you find your lilacs in, know that there is help and — as soon as next spring — a chance for renewal that will allow Laura’s love affair with lilacs to start anew.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.