Excess moisture and cold temperatures in late spring/summer, a sneaky insect pest, a plant disease; all of which can cause individuals frustration when trying to grow plants. This article provides a current overview of plant issues challenging farmers, gardeners and homeowners.
The first step in solving a plant problem is looking for evidence. Taking a representative sample in a timely manner is crucial. Ideally, we would hope that you are checking on your plants daily or every other day to ensure they are healthy. The next step is to determine if the problem is caused by a living organism (biotic) or a non-living causal factor (abiotic).
Some abiotic factors we are seeing in the area include soil compaction and poor rooting due to wet planting conditions. In 2025, we have seen some delayed/sporadic bud-break in some trees because they did not receive enough “chilling hours” to impact their internal growth inhibitors. Herbicide drift is another potential abiotic causal factor that requires careful investigation by the Office of the Indiana State Chemist.
Once we rule out abiotic factors, then we evaluate possible biotic factors. A common biotic factor is fungal diseases like fusarium, blight, and rust. About 85% of biotic factors are caused by fungus. As you may guess, this year, we have seen a fair number of issues related to fungal diseases including anthracnose in shade trees.
Insect damage is always a challenge because so much of their damage is caused when we are not present. Insects either chew on a plant or suck the sap. Cabbage riddled with chewing holes is often caused by the cabbage looper, the larval stage of the white moth hovering around your cruciferous vegetables (broccoli, cabbage, cauliflower and radishes for example). It can also impact alfalfa, tomatoes and peppers.
To make matters worse, there are some issues that can be caused by both abiotic and biotic factors. One example of this is blossom drop in tomatoes. Abiotic factors such as extreme temperatures, water stress, nutrient imbalance, humidity, lack of pollination and excess wind can all cause blossom drop. Some pests, diseases and heavy fruit set are biotic factors that can cause it too. Therefore, some detective work must be done to determine what caused tomatoes to drop their blossoms without forming fruit.
After we identify the cause, we can take appropriate measures to treat the issue. Sometimes we have no real treatment to recommend. Other instances may warrant a pest control treatment following label recommendations. We don’t recommend home remedies that are not research based.
The summer is young and plant problems will keep coming until frost. Contact the Purdue Extension Putnam County office at 653-8411 or e-mail smith535@purdue.edu with photos and information about the different plant problems you are dealing with. If the problem is more challenging, we can arrange a site visit.
Challenging issues may require submitting a sample to the Purdue Plant and Pest Diagnostic Lab (PPDL) for $11. Some inquiries will not justify $11, so Purdue Extension will try their best to identify the issue and provide a control recommendation without the expense.
Visit www.extension.purdue.edu/putnam or contact the local Purdue Extension Office at 653-8411 for more information regarding this week’s column topic or to RSVP for upcoming events. It is always best to call first to assure items are ready when you arrive and to RSVP for programs. While many publications are free, some do have a fee.
July 3 – Extension Office closed until 1 p.m.
July 4 – Extension Office closed for 4th of July
July 7 – Fair entry due
July 7 – Indiana Quality Assurance (IQA) trainings, 1:30 p.m. and 7:30 p.m., Fairgrounds, register under the Events tab in 4-H Online
July 18-25 – Putnam County 4-H Fair
Aug. 1-17 – Indiana State Fair (closed Mondays)