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Cooperative Extension

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Check pesticide credits

To check your applicator recertification credit status, please choose your category.




If you have any questions about your credit hours, please email the Department of Pesticide Regulation's Recertification program.


Take a soil sample

To have a soil analysis done you need to collect 8 to 10 or more core samples, which will be combined as one composite sample. The composite samples should include soil from the surface to a depth of 6 inches in all areas, except for lawns where core samples should be taken from a depth of only 2 to 4 inches. A simple garden trowel can be used to collect the core samples.

Landscape professionals may use a soil probe to collect soil core samples, which will create little damage to the lawn.

Place the core samples in a clean plastic bucket and mix them thoroughly. Keep sampling separate from areas that have been fertilized or limed differently, such as lawns, shrub beds, and vegetable gardens. These should be submitted as separate composite samples. It is imperative to use clean sampling tools. Pesticide or fertilizer residues will create misleading results. Additionally, the sample must not be excessively wet before it goes to the lab.

How many samples to take?

You need to dig and have tested a composite soil sample from each section of your yard or garden. Usually this means, for example, one composite sample in your turf area, one in any foundation or perennial bed, and one in your vegetable garden. If you have a problem area where plants or turfgrass do not seem to grow well, take a separate soil composite sample from that location in addition to the sample from the non-problematic area.

Sampling frequency

The Clemson University Extension Service recommends soil sampling every year.

Timing of sampling

Soil samples can be taken at any time of the year, but it is best to sample the soil a couple months before planting a garden, establishing perennials, or before the optimum time for fertilizing lawns to allow ample time for the lime to react with the soil.

Get help with my soil sample results

South Carolina residents can contact Clemson's Home & Garden Information Center (HGIC) for assistance with their soil sample results. Please email HGIC or call 1-888-656-9988.

ID an insect

Clemson entomologists working with the Plant and Pest Diagnostic Clinic (PPDC) identify insect and arthropod pests of plants, those found in and around structures and properly submitted parasites. Once the insects are identified, crop commodity or other specialists will provide management recommendations. This procedure adds some time to the reporting process. If the client includes an email address, the identification will be sent as a preliminary report and the specialist’s report will follow. Otherwise, reports will be mailed upon completion.

To use our services, complete the Insect Identification Form or obtain a copy from your local county extension office. When collecting a sample, make note of the population present and if there are many of the same insect present, include more than one insect in the sample. If more than one type is present, each should be submitted as a separate sample. Complete the form, providing all information requested.

Due to sample quality, biosecurity and health issues, insects submitted to the Clinic should be killed before submission. Most insect samples can be placed in a vial or other container filled with alcohol. Either ethanol or isopropyl (rubbing) alcohol (70% solutions) can be used. Ethanol is the better preservative but isn’t as readily available for this use. These preservatives allow the insects to be relaxed as they are killed, ensuring that they reach the Clinic in good condition. Be sure to fill the vial to the top to prevent specimen damage due to sloshing. Do not use water or any other liquid. Insects placed in hazardous preservatives, such as formaldehyde, will not be accepted.

Using alcohol is especially important when human parasites, such as fleas, lice or ticks, are submitted, as blood from the person is considered a biohazard. In addition, if clothing, air filters or other such articles were to be submitted, the entomologist performing the identification could be infested. For these reasons, human or animal pests will only be accepted by the PPDC in small vials filled with alcohol. If a client suspects human parasites are present but finds no actual insects, he/she should visit a dermatologist and if insects are found, they can be submitted as described above. If the person brings unpreserved insects to a county office, these should be placed in a small vial of alcohol for submission.

Small pests on plants can be submitted live on the affected plant part but must be double bagged for biosecurity reasons. Enclose the plant material, along with some dry paper towels as packing material, in a zip- lock plastic bag. Then place that bag in a larger zip-lock bag. Large, fragile insects, such as moths or butterflies, should be killed in a freezer, wrapped gently with tissue paper and submitted in a crush-proof container without alcohol. Package all samples with packing material to prevent crushing.

Larval insects, such as caterpillars, grubs and maggots usually aren’t identifiable to genus due to immaturity. Identification to at least the family level will be attempted but cannot be guaranteed. However, management recommendations are often possible even for insects identified to the family level. If identification to genus is needed for scientific reasons, contact the Clinic to request submission of live insects for possible rearing to maturity.


Depending on sample load at the time, preliminary replies can be expected from 7 - 10 days following sample receipt in the Clinic. During cooler seasons, replies may come more quickly. All replies are sent via email to clients and also to the affiliated county extension office. Agents included on the form will also receive a copy. If the client has no email address, their report is mailed, even if an agent is also receiving the report via email.

ID a plant problem

Clemson's Plant and Pest Diagnostic Clinic (PPDC) diagnoses diseases of all types of plants. If insects or cultural problems are found, these are also investigated.

To submit, complete the Plant Diagnostic Form or obtain a coy of the form from your county extension office.

Select as much recently affected plant tissue as possible, making an effort to represent all stages and aspects of the problem. Provide material which shows a range of symptoms present on the plant. Dead tissues are often useless for diagnosis, but some dead material can be included to represent the range of symptoms. Do not wash samples, as this may remove pathogen structures and encourage growth of secondary organisms. Several plants of the same kind, with the same symptoms, may constitute a representative sample and be covered by one submission fee.

Including photographs or digital images of the affected plant(s) in their environment is encouraged, but close- up photos usually aren’t necessary. Enclose plant diagnostic samples in sturdy plastic bags to prevent tissue desiccation. Never add water or wet paper towels, as this encourages growth of secondary microorganisms and may lead to sample decay. Avoid sending wet or dirty leaves for the same reasons.

If plants are potted, submit entire plants in their pots and package well to prevent toppling during shipment, which can result in rotting of above-ground tissue due to soil contamination. When roots and soil are included from field-grown plants, enclose the roots in a plastic bag and tie off at the stem, or pack roots in a separate plastic bag.

It is very important to submit samples soon after collection. If submission must be delayed, keep samples cold, but not frozen, before mailing. Be sure to provide dates of sample collection and mailing. This information, along with a complete description of the problem, is needed so that damage or contamination of the sample during transit will not be confused with the real problem.

Consider that the source of the problem may be abiotic, or non-living. Because of this, be sure to complete the form, giving information on plant care, fertilizers, specific pesticides and other chemicals that have been used on or in the vicinity of the plant. Also, be assured that if the sample is deemed insufficient by diagnosticians, one free resubmission will be granted. Only diagnosticians can make this determination.

Packaging and Mailing Samples

It is best to pack samples in boxes to prevent crushing. Use ample packing material to prevent shifting and tumbling in transit. This will help to maintain sample quality during shipment. Consider the nature of the sample before mailing, as samples delayed in the mail are more apt to deteriorate in transit. Mail samples early in the week and they should arrive during the same week. The Clinic supplies plastic bags and insect vials for the counties to use for sending samples. County offices can request these by sending a form from the website to the Lab Coordinator, Diana Low, who will package and mail them as soon as possible after receipt of the request.


Depending on sample load at the time, replies can be expected from 7 - 10 days following sample receipt in the Clinic. During cooler seasons, replies may come more quickly. All replies are sent via email to clients and also to the affiliated county extension office. Agents included on the form will also receive a copy. If the client has no email address, even though preliminary reports will generate, only the final report will be mailed.

Guidelines for Specific Types of Plant Disease Samples

Leaf spots:

Collect at least 6 to 12 leaves representing all stages of infection. For plants with small leaves, cut off a branch with leaves intact. Highly succulent leaves should be treated as described in the next section.

Fruits or other fleshy tissues:

Avoid packing fruit, fleshy leaves or other fleshy organs showing advanced stages of rot; select early stages of infection or damage. Wipe off excess moisture and wrap fruits individually in dry paper and place in a paper bag. Such samples are highly perishable so overnight mail is recommended.

Stem lesions, diebacks, cankers, and galls:

Select branches with active lesions or young galls. Cut branches to include the affected area and a healthy portion on the same branch, if possible. Completely dead branches and twigs are generally undesirable for diagnosis, but may be included, along with more recently declining ones, to show a range of symptoms.

Turfgrass samples:

Cut out blocks of sod (grass with roots and soil attached) of at least 6 x 6 inches, to include the margin between affected and healthy areas. Place in a sturdy plastic bag and press to release trapped air.

Plants exhibiting wilting, yellowing, and general decline:

Submit entire plants, if possible. If they are container grown, submit several affected plants in their pots, if possible. If they are field grown, carefully dig them up and place soil-covered roots in one plastic bag, tie at the trunk, and secure another bag over the top. For large trees and shrubs, submit branches or other parts showing typical symptoms in a plastic bag. Include a handful of fine feeder roots, plus a few larger ones, of at least 1⁄4 inch in diameter. Place roots in a separate plastic bag with a small amount of moist soil. Make sure that the roots submitted are from the plant itself, not from weeds, grass or ground covers growing below the affected plant.

Viral symptoms:

Mosaic patterns, chlorotic ring spots, and distorted new growth are common symptoms of virus diseases. Only a select few viruses can be identified through the PPDC but samples can be sent from the Clinic to a commercial lab at an additional cost, if desired. Send virus assay samples by overnight delivery.


If nematode problems are suspected, soil from the sample can often be used to test for these microscopic round worms, but an additional fee will be required. If the Diagnostician suspects nematodes, clients will be notified and asked about testing. If agent suspects nematodes, clients should be encouraged to submit nematode assay samples. Collect a pint of soil from the advancing margin of decline and enclose in a nematode bag or small plastic bag. Do not allow the soil to dry out or become overheated during shipment.

It is helpful when clinic and nematode samples are submitted separately, that this information be provided on the diagnostic sample submission form. If more than one sample is submitted, be sure to label the bags and provide these field ids on the form as well. Nematode assay results will be sent by NAL lab personnel.

Join 4-H

New youth members and adult volunteers

Visit 4-H Online and select "Don't have an account?".

You will select South Carolina and the South Carolina 4-H Youth Development and then the county you live in.

Once you have selected the county, you will enter an email address - this will be the email address you use when you log into your child's account.

Existing or returning members and volunteers

Anyone that was a 4-H member the last 3 years should have a profile with 4HOnline and be able to re-enroll for the current year.

Visit 4-H Online

You will need your email address that you have been using.

For questions or concerns, please contact your local county 4-H extension agent.

Test my irrigation water

Irrigation water can be tested where a problem with salinity is suspected.

Growers who would also like to check the plant nutrient content of their water or pinpoint a specific element which may be causing a toxicity problem due to excessive levels can also benefit from an irrigation water analysis.

This service is not intended for assessing water for drinking purposes. Drinking water samples will need to be taken to your nearest DHEC office. 

Our lab does not accept international samples for analysis.

Irrigation Water Testing