Get It Growing for 03/06/26

When a beloved plant isn’t doing well in the garden, it can feel a bit like dealing with a sick pet or young child. They can’t tell you what is wrong — but that doesn’t stop you from wanting to help them get better.

That’s where plant doctor Raj Singh and his team at the LSU AgCenter Plant Diagnostic Center can come to the rescue.

“Plants get sick, too, like we get sick,” said Singh, who holds a doctorate in plant medicine. “At the Plant Diagnostic Center, if you send us your sick plants, we can determine the cause of their sickness.”

Lots of things can make plants sick: fungi, bacteria, viruses, nematodes, insects, even stress caused by nutrient deficiencies or the weather. Differentiating between pathogens and environmental causes of plant health problems is crucial. They often produce similar symptoms but can require drastically different treatment plans.

In their lab on the LSU campus in Baton Rouge, Singh and his staff examine hundreds of plant samples mailed from across Louisiana every year. Anyone who works with plants — commercial growers, homeowners, landscapers, extension personnel — can submit samples.

“We triage the samples when they come in, and based on the symptoms, we conduct diagnostic tests on the roots and on the foliage. It depends on the symptoms that the plants are exhibiting,” Singh said. “We can culture those pathogens and root out the possibility of if there’s a pathogen involved in it or not.”

Clients are informed of the diagnosis and given recommendations for managing the condition.

If you’re interested in sending an ailing plant to Singh’s lab, it’s important to collect and package the sample properly.

“Our diagnostics depend on how good the sample is,” Singh said.

If possible, send an entire plant, not just a cutting. This allows Singh and his team to run multiple tests on the roots, leaves and other plant parts — helping them accurately diagnose the problem.

Once you’ve dug up your plant, don’t simply toss it in a bag or box and ship it to the lab. Loose soil can interfere with testing.

“There are so many microorganisms in the soil that can contaminate the rest of the plant, so it’s really hard for us to find the actual cause of the problem,” Singh said.

Instead, securely wrap the plant’s roots in a plastic bag, then put the whole thing in another plastic bag.

Before mailing your sample, be sure to fill out a submission form.

“It’s very important that we know the history of cultural practices, including use of fertilizers or chemicals sprayed on plants, and any other events that led to the first appearance of symptoms on your plants,” Singh said. “Also, we need to know what was happening during that time period to figure out if it is actually a plant pathogen or just an environmental factor that is causing those symptoms.”

Routine diagnostic service costs $20. If needed, more tests can be conducted for an additional charge.

For more information, including a submission form and detailed instructions for packing samples, visit www.LSUAgCenter.com/PlantDiagnosticCenter. You also can call the Plant Diagnostic Center at 225-578-4562.

LSU AgCenter horticulturist Jason Stagg visits AgCenter plant doctor Raj Singh at the Plant Diagnostic Center to learn how plant health problems are diagnosed.

LSU AgCenter plant doctor Raj Singh is in charge of the Plant Diagnostic Center. Photo by Olivia McClure/LSU AgCenter

LSU AgCenter plant doctor Raj Singh, left, talks with extension associate Tim Burks. They’re standing next to lab equipment that is used to diagnose plant health problems. Photo by Olivia McClure/LSU AgCenter

When submitting samples to the Plant Diagnostic Center, avoid placing a plant in a bag with loose soil, which can interfere with testing. Photo by Olivia McClure/LSU AgCenter

LSU AgCenter plant doctor Raj Singh shows an example of a properly packaged sample. The plant roots are secured with a plastic bag to prevent loose soil from moving around, and the entire plant is placed inside a second bag. Photo by Olivia McClure/LSU AgCenter

Plant roots are seen inside a plastic bag that was sent to the Plant Diagnostic Center. Photo by Olivia McClure/LSU AgCenter