Diagnostic Services for Plants, Insects, and Soils

For information or help with your garden, lawn, trees, or plants in general, you can contact the Master Gardener Hotline via email (mghotline@gmail.com) or call (260-481-6425). This is a free service.
Emailing photos is a great way to identify plants or insects OR diagnose problems you are seeing with your garden, lawn, trees, or houseplants.

General Digital Photo Tips (Source: PPDL)

You can help us by following these guidelines:

1. Please check your images before submitting them. If they look out of focus to you, they will not be helpful to us.
2. When possible, please include a size reference such as a ruler or a coin. If taking a photo of a ruler, let us know units (ie. Size is about 2 mm).
3. For plant identifications, please include whole plant image, as well as close-ups of plant parts (leaves, flower, fruit, etc.)
4. As with actual samples, please include as much additional information as possible such as: planting date, age of plant, chemicals used, number of plants affected, where found, patterns, when symptoms first noticed, etc.
5.  Download the Image Guide for Tree Diagnosis – PDF 

• Want to bring in a sad plant, mystery flower, or unidentified creepy crawly for us to help you with? Please see our general guidelines below for submitting samples. For information needed when bringing in samples, see Sample Submission Form. A nominal fee ($5) will be collected at the time of submission.
  
  The Purdue Extension – Allen County office had limited diagnostic capability. We can only diagnose based on visual inspection of the issue with normal microscopes and tools. You may need to submit samples to the Purdue Plant and Pest Diagnostic Lab (PPDL) for full verification through disease or viral testing. There are additional fees for this and we recommend submitting samples directly to PPDL (See below).

SUBMITTING PLANT SPECIMENS FOR DISEASE/INJURY DIAGNOSIS (SOURCE: PPDL)

HERBACEOUS PLANTS

For general decline/dying of plants, send whole plants, showing early symptoms, with roots and adjacent soil intact. Dig up plant carefully. Send several plants. Bundle plants together and wrap roots in a plastic bag. Wrap the entire bundle of plants in newspaper and place in a crush-proof container for shipment. Do not add water.

TREE WILTS

Collect branches ½ to 1 inch in diameter from branches which are actively wilting but not totally dead. Wrap in plastic to retain moisture. Collect a handful of feeder roots and place in a separate plastic bag.

LEAVES/BRANCHES/FLESHY PARTS

When localized infections such as cankers, leaf spots, and rots are involved, send specimens representing early and moderate stages of disease. For cankers include healthy portions from above and below diseased area. Press leaves flat between heavy paper or cardboard. Wrap fleshy parts in dry paper.

TURF

Samples should be at least 4”x4” and include both the diseased and healthy portions of grass on the same sample piece. Place the sample on a disposable plate and wrap in newspaper for shipment.

SUBMITTING PLANT SPECIMENS FOR IDENTIFICATION

1. Include a 6-10 inch sample of the terminal (tip) portion of the stem with side buds, leaves and flowers in identifiable condition.
2. Place the sample flat between a layer or two of dry newspaper, paper toweling or similar absorbent material. Try to prevent excessive folding of the leaves and place flowers so that you are looking into the center of the flower.
3. Pack the wrapped bundle in plastic, preferably with a piece of cardboard to keep the sample flat.
4. Never place any fresh plant sample directly in plastic.
5. Never add water to the sample.
6. Shake excess water from aquatic weed samples and place in plastic bag.
7. Wrap whole, uncut fruit specimens in paper, place in a strong box, and pack with additional paper to prevent crushing.
8. Package in sturdy crush-proof container and pack with additional paper to prevent shifting.

SUBMITTING INSECT SPECIMENS

Care should be taken to package insects so that they arrive unbroken. Be sure to separate and label the insects if two or more are included in the same package and provide appropriate information on each.

TINY AND/OR SOFT-BODIED SPECIMENS

Aphids, mites, thrips, caterpillars, grubs, spiders, etc. should be submitted in a small leakproof bottle or vial of 70 percent alcohol. Rubbing (isopropyl) alcohol is suitable and readily available. Do not submit insects in water, formaldehyde or without alcohol as they will readily ferment and decompose.

*Grubs and caterpillars must be prepared before preservation to prevent discoloration. Drop them into gently boiling water for about 30 seconds (never microwave them!) before placing in vials of rubbing alcohol.

HARD-BODIED SPECIMENS

Flies, grasshoppers, cockroaches, wasps, butterflies and beetles can be submitted dry in a crush-proof container. Do not tape insects to paper or place them loose in envelopes.

• The Purdue University Plant and Pest Diagnostic Laboratory works to diagnose plant diseases and identify insects, plants and weeds and other plant and pest problems. This service is provided for the specialists and county extension educators of the Purdue University Cooperative Extension Service and Purdue University's research faculty, staff, and students as well as for private businesses and citizens of Indiana.​ More information is found at https://ag.purdue.edu/department/btny/ppdl/index.html.

• Understanding the nutrient levels and pH of your soil is beneficial to maintaining healthy crops, lawns, and gardens. We offer soil testing services to assist you in maintaining healthy soils and plants. Our soil samples are processed by A & L Great Lakes Labs. Both you and our office receive a copy of the report. An extension educator can provide a consultation on the results if you contact us once you have the report.

Our basic sample:

• $20 per sample fee includes soil report plus consultation with an extension educator
• Report includes pH, phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca), and organic matter levels
• Report includes recommendations for nutrient application for the above plus nitrogen (N)

Micronutrient sample:

• $30 per sample fee includes all basic sample services plus micronutrients
• Micronutrients include Sulfur, Zinc, Manganese, Iron, Copper, Boron

Soil testing services require 2 cups of soil per sample and payment in cash or check. Instructions on collecting soil samples can be found below.

We generally estimate 7-10 business days for results to reach you. We find emailed results arrive more quickly than mailed results. If you have questions about your results, please contact one of our Extension Educators.

At this time we do not offer testing for plant tissue, compost, or heavy metals. We recommend reaching out directly to a certified lab for these services. A listing of certified labs can be found at https://ag.purdue.edu/department/btny/ppdl/extension/publications.html.

Proper soil sampling techniques are important to obtain accurate soil test results. Purdue Extension publication HO-71 entitled Collecting Soil Samples for Testing provides specific advice on how to take a proper soil sample in a home garden or lawn.

Proper soil sampling techniques are important to obtain accurate soil test results. Purdue Extension publication AY-368 entitled Soil Sampling Guidelines provides specific advice on how to take a proper soil sample for field crops and pastures.

Here are some additional resources to assist with understanding your soil analysis and correctly applying fertilizers.

Explanation of Soil Analysis Report 

Interpretive Guide for Soil Test Reports 

Purdue Turf Fertilizer Calculator 

Fertilizing Established Lawns AY-22 

Purdue turf publications for maintaining home lawns 

Fertilizing Woody Plants HO-140 

Home Gardeners Guide HO-32 

Purdue Agriculture soil fertility website