Troubleshooting

Plant Diagnosis and Specimens

Bulletin #1010

Horticultural Observations for Healthier Landscapes

Getting the right diagnosis for your ailing plant requires some careful observations on your part as well as providing a specimen that will give diagnostician enough to go on. It is strongly recommended that you complete the "Diagnosis Submission Form" before bringing or sending your specimen into the store for observation. Please read the "Guidelines for Collecting Plant Samples" to help assure that you receive the most accurate diagnosis.

◊ PLANT DIAGNOSIS REQUEST SUBMISSION FORM

GUIDELINES FOR SUBMITTING SPECIMENS FOR DIAGNOSIS

Please read and follow these instructions before submitting specimens.

Collecting Plant Samples

Provide as much information regarding the specimen as possible. Filling out a "Plant Specimen Submission" form will help assure a better and more complete diagnosis.

Identify the plant material (variety), the current size (when applicable), and indicate the percentage of the plant affected with this symptom.
Indicate when the symptoms first started and whether or not the symptoms are continuing to develop or spread.
List all cultural practices such as irrigation frequency (days per week), rate (type of emitter and minutes per watering).
List any/all chemical applications (herbicides, insecticides, fungicides, etc.) and when applied.
Specify your fertilizer regime.
Try to give an estimate of the weather conditions preceding and during symptom development.
Indicate the type of environment in which the plant is growing (lawn, flower bed, pot, house, etc.) A photograph of the plant in its environment, when available, can be extremely helpful to the diagnostician.
Indicate whether the landscape has been altered in the area of the plant. If so; When?
Indicate the sun/shade conditions for the plant (morning sun, all day sun, deep shade).

Select plant sample material showing the symptoms. If possible, it is best to send/bring several samples showing various stages of the problem. Early stages of symptom development are especially important.
Send samples of all plant parts, including roots whenever possible. Aboveground symptoms may be caused by root or stem diseases; thus examining all parts can be essential for an accurate diagnosis.
Send several affected portions of the plant. Remember to include the margin of disease on stem and branch samples.
If you suspect disease, send a sample from dying or wilted branches with yellow leaves. Remember, do not send dead wood. Place several branch sections 1/4-1" in diameter and approximately 6" in length in a plastic bag. This will prevent the sample from drying in transit.
Turfgrass samples should be taken from the edge of the affected area and include both dying and healthy plants. Do not send a section of only dead grass. Send several 3" x 3" squares of sod including as much soil beneath the grass as exists. Wrap the sample in a thin layer of damp (not wet) paper toweling, then wrap in dry newspaper.
Fleshy specimens such as fruit, mushrooms, or other fungal fruiting bodies should be as firm as possible and show both early and intermediate symptoms. Wrap specimens separately in dry paper toweling or dry newspaper. Do not put in plastic. Pack specimens so they are not crushed during shipping.
If sending a complete plant, dig the plants (do not pull them) out of the soil. Pulling plants out of the soil will generally break off the roots, especially if they are rotten. Retain a small amount of soil around the roots. Do not wash roots. Keep the roots and soil separate from the aboveground parts of the plant by placing them in a plastic bag and sealing them off with a rubber band.