Please see the below guidelines for providing samples to the Buchanan County ISU Extension Office for diagnosis by the local Consumer Horticulturist.


Tips from Buchanan County’s Consumer Horticulturist on Submitting Plant & Insect Samples


For Weed/Plant ID:

Please include the following (available) parts of the plant:

·         Flower/ Buds/Fruit/Seeds

·         Roots

·         Leaves

Please provide only fresh samples!


For Plant Disease Diagnosis:

Please include a diseased portion of the plant as well as a healthy portion (if available).  When bringing in samples please make sure to keep the samples as intact as possible and transport them in a container (whether it’s wrapped up in newspaper, paper towels, or intact inside a plastic bag with ventilation).  Please bring in a specimen that includes the following (available) parts of the plant:

·         Flower/ Buds/Fruit/Seeds

·         Roots

·         Leaves

Please provide only fresh samples! 


For Insect ID:

Please bring insect in appropriate container (see below):

·         Alive:  in a clear jar or plastic container that you do not expect to get back.

·         Dead:  in a plastic container or plastic bag that you do not expect to get back.


Woody Plant Material Specimens (for ID or disease diagnosis):

Please provide a branch specimen that contains a leaf or fruit/nut sample; better if a healthy and an ailing sample are provided!  Please provide as fresh of a sample as possible.  If providing a sample for ID, please include a sample of roots/bark/foliage (if possible); or clear, high resolution photos of the portions of the woody plant that you are not able to provide.  Please do not bring in samples that have fallen off the tree/shrub and have been on the ground.  Please provide fresh-as-possible samples only!


For providing photos of plant/ insect specimens for diagnosis

Please take several photos of the specimen for diagnosis (we prefer more than less, often times something you might not see as out-of-the-ordinary is what is used to diagnose the problem)!  Please take the photos at a high resolution so pictures are larger and clearer for assessment.  For photos of trees, please take good pictures of the canopy and foliage, the fruit or nuts, the bark, the roots, and the ground around the tree.  For photos of insects, please place the insect near a ruler or another measureable object (such as a quarter).


Photos may be emailed to the Consumer Horticulturist at:  sherrets@iastate.edu

Please include your name, phone number, and some history as to how long the problem has been occurring, what types of plants the insect is affecting or where it was found, if there are multiple insects or multiple weeds, and if multiple plants/trees are experiencing the disease/insect infestation.


Below are the guidelines of sending samples to ISU for diagnosis.  Should the Buchanan County Consumer Horticulturist not be able to diagnose the plant problem or identify the weed or insect, a sample may need to be sent to the ISU Plant & Insect Diagnostic Clinic.  Plant & Insect Sample Forms are available at the Buchanan County ISU Extension office.



Submitting Plant Samples

(information from the ISU Plant & Insect Diagnostic Clinic)

General Tips


·         Provide plenty of plant material. When possible send the entire plant, including roots and top growth.

·         Provide lots of information, such as a description of the soil, nearby plants, and a history of the problem.

·         Include photos when possible. We welcome videos and will return them to you.

·         Provide freshly collected specimens.

·         Be sure the specimen represents the problem.

·         Include enough plant material to show all stages of the disease from healthy to very sick.

·         Wrap specimens in paper towels or clean newspapers. Do not add moisture. Pack loosely in a plastic bag to reduce drying. Mail in a sturdy container

·         Submitting herbaceous plant samples


Submitting herbaceous plant samples

When possible, include the entire plant, with the root system and surrounding soil. Often what appears to be a leaf problem is really a root-related problem. Enclose the root ball in a plastic bag to keep the soil from touching the leaves. Include enough plant material to show all stages of the disease. When possible, provide several whole plants.



·         Before applying any disease-controlling chemicals, collect turfgrass from the edge of the affected area. The sample should include both healthy and infected plants. Completely dead grass is of no use since secondary organisms quickly colonize it.

·         Take a sample of at least 6" diameter (a cup cutter works well). Include the underlying soil and root system.

·         Wrap the sample in newspaper or paper towels. Please do not place it in a plastic bag and do not add water. Excess moisture can cause rapid deterioration of the sample and proliferation of secondary organisms.

·         Provide background information, such as when symptom first appeared, turfgrass variety, and pattern and distribution of the problem. Pictures of symptoms can be very helpful.


Woody plants

Collect samples from branches that are showing symptoms but are not dead.

For Dutch elm disease, oak wilt, and Verticillium wilt testing, branch specimens should consist of four to six pieces, measuring 6 to 8 inches long, and 1/2 to 1 inch think.

When submitting cankers, include the portion of the branch at the border between discolored and healthy bark.


Sample Submission

The ISU Plant and Insect Diagnostic Clinic staff can diagnose plant health problems caused by diseases, insects or the environment. In addition, they also can identify insects, weeds and fungi. Once they have diagnosed your disease or identified your insect pest, they can advise you on the best course of action to take.




Submitting Insect Samples

Insect, spider, tick and mite specimens can be submitted by e-mail or mail to the Plant and Insect Diagnostic Clinic for identification at no charge.

Whichever method you choose we will need a little background information. Where and when you saw your insect.  How many you are seeing.  Your county of residence and how you would like us to get back in touch with you.

E-mail:  You can e-mail a close-up digital image to insects@ iastate.edu

Extension office:  You can also take your insect to the Buchanan County Extension Office and have it identified.

Mail: You can send your specimen directly to us.  Specimens should be dead when mailed.  Please mail in a box or padded envelope to prevent crushing. Soft-bodied insects such as caterpillars, aphids, spiders can be preserved in hand sanitizer gel.  Hard bodies insects such as moths, butterflies, beetles, ants and ticks do not need to be preserved, but should be restrained in container so they don't bounce around too much in the mail. 


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