How to Get Help for Sick Plants

How to Get Help for Sick Plants

Part of Ep. 902 Sex and Roses

Properly prepare samples of sick or diseased plants before sending them to the lab.  Plant Pathologist Brian Hudelson, director of the UW-Extension Plant Disease Diagnostics Clinic, explains how.

Premiere date: Jul 25, 2001

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
You have a plant that's looking decidedly unwell. What do you do? Can you fix it, can you cure it? Where do you go for help? Let me introduce you to somebody that maybe can assist us. This is Brian Hudelson, with the UW-Madison campus. And Brian, I have a plant that's dying, how can you help me?

Brian Hudelson:
Yeah, well I'm the director of the Plant Disease Diagnostics Clinic, it's a service provided by the UW-Extension where you can send plants, either whole plants or part of a plant. We'll take a look at it for disease problems and try to figure out what's going on, and give you some information on what the problem is and how to take care of it.

Shelley:
So you can actually cure this problem.

Brian:
Well, we don't really talk about curing plant diseases, that's actually very difficult to do. What we normally talk about is trying to prevent diseases from occurring or if you have several plants of the same type, one of which is diseased, we try to help you figure out how to prevent that disease from spreading to other plants.

Shelley:
Okay, so that there is a chance that we can end up with a garden that's alive by the end of the summer.

Brian:
That's right.

Shelley:
Okay. Where do we begin?

Brian:
Well, let's talk first about maybe some of the sorts of samples that I don't like to see come into the clinic. This is the prime example of something that we don't like to see coming into our lab. We affectionately call this slime in a bag.

Shelley:
What was it?

Brian:
Well, that's the question. And that's part of the problem, if we don't know what the plant is, it's going to be somewhat difficult for us to tell what the problem is. This is a plant that was kept too long in the sun, it got too hot and its just disintegrated. So, kind of the first rule if you're collecting plant samples is to keep them cool.

Shelley:
Okay.

Brian:
So, once you've collected the material–if you can collect it right before you're going to send it to us, that's great, if not, put it in a refrigerator, or if you don't have a refrigerator available, use a cooler with some ice or one of the cold packs.

Shelley:
Don't put it on the hood of your car in August.

Brian:
That's right, it will rapidly turn into this sort of mess.

Shelley:
Now, what about sample size? You gave me this little twig, is that okay?

Brian:
Yeah, that's a little bit small for what we like to do. Typically, if we're going to have a plant, we like to see an entire plant like this coleus. Sometimes you're not going to be willing to send us a plant if it's the only plant you have, but if you have several plants that are having a problem, and you can send us a whole plant, that is great. And, just package it up like we have it here. There's a plastic bag around the base of this plant.

Shelley:
Why?

Brian:
Yeah, we want to keep the soil off of the leaves. That's very important for us to do a diagnosis. The other thing is we want to see the root system, because lots of times you're seeing problems in the upper part of the plant, and actually it's a function of something going wrong in the roots. So, we need to see that root tissue.

Shelley:
Now, we don't have to send it in the pot. You've got one here that's just got the roots in a bag.

Brian:
Yeah, if you have a special pot that you've planted that coleus in and you don't want to send it to us, just kind of gently take it out of the pot. Again, wrap the root system in a plastic bag, tie it off with some twist ties, and that will work fine. Same thing if you have to dig it out of your garden. And I emphasize, dig.

Shelley:
Gentle.

Brian:
Yeah, you want to be gentle, you don't want to pull the plants out because you can strip off a lot of the root tissue, when that may be exactly where we need to be looking for the organisms that are causing the problem.

Shelley:
Okay, I've got a 12-foot tree in my backyard, obviously, I can't send the whole thing in, you don't want me to send in a little twig.

Brian:
That's right.

Shelley:
So what do I do?

Brian:
Yeah, what we normally suggest is something like this, about 12 inches long, bigger is better. We have had full trees in our lab, but typically a 12-inch branch size is pretty typical. We like to have a branch that has part disease, so this brown area here, and part of it still alive. Because the pathogen of disease causing organisms is most active right at that interface, and that's where we're going to find it.

Shelley:
Now, am I putting this stuff in the mail?

Brian:
Oh, sure. Not a problem, if you have a plant, even a whole plant like this or branches, you can stick it in a box, and add some packing material like newspaper or packing peanuts, and just send it off to us.

Shelley:
Promptly.

Brian:
Promptly, that's right. Now if you have a branch like this and you don't have a large box, one of the things you can do is illustrated with this bag, where we've taken a branch and we've just chopped it up into little pieces. You can see the brown branch pieces at the bottom. And put it in a bag with a little bit of moist paper toweling, you may want to punch a couple of holes to let some air in. If you decide to send us more than one branch, which we usually recommend, and you're going to chop it up like this, at least put the pieces from a single branch in a single bag. So separate bags for each branch.

Shelley:
So, for each site, each sample, keep them separate.

Brian:
That's right.

Shelley:
Okay, what do you have here then.

Brian:
Yeah, if you are interested in sending in leaves, sometimes you have a leaf spot, and what we recommend for this is just some sturdy cardboard with pieces of paper toweling, with the leaves inside. And if you want to, you can lightly moisten the paper towels, but again, don't get it too wet because these will turn to slime fairly rapidly as well.

Shelley:
So, again, don't let these sit around, get them in the mail.

Brian:
Right, that's right. And if you have the option of sending overnight mail, that's really great, that works best.

Shelley:
Okay, now you've got one here, I'm not opening this.

Brian:
Yeah, well, this is a potato tuber which is one of my least favorite samples to get. We get a lot of these in the fall from commercial growers. With these sorts of samples, fruits and vegetables, lots of times when they're decaying, they're fairly moist already, so we don't want to put them in moist paper towel, we just use something like newspaper, wrap them like this, again, in a box with some packing material, and you can send it off to our lab.

Shelley:
Mail it quickly.

Brian:
That's right.

Shelley:
Do we put money in with our plants.

Brian:
No. We do charge a nominal fee for our services, but that's not necessary, you can pay us after the fact. Once we've sent you a report on the disease, if we have any literature on the disease we'll also send that to you. One thing you do need to include in the box, though, is a letter with your name, mailing address, telephone number, we lots of times need to do a follow-up call to get some additional information. And then if you can provide a brief description of the disease you've been seeing in your garden or when it started, how it progressed, weather conditions, that sort of thing, anything you think would be useful to help us make our diagnosis.

Shelley:
Okay. Now you've got all of the information we've talked about and current prices in this neat little brochure too.

Brian:
That's right, and you can pick that up at your county Extension Office, and actually, the county Extension people are a good place to start if you're having disease problems. A lot of our ag. agents, and particularly our hort. agents are very knowledgeable about plant diseases and can often help you and you don't even have to send a sample to my lab.

Shelley:
But if we want to, that's okay too.

Brian:
That's fine, you can either send it through the county office or directly to the clinic.

Shelley:
Okay. Thanks a lot for the information Brian.

Brian:
Now stay with us, we're going to give you the name, address, phone number, and web site so that you can get in touch with these folks.

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