Managing plant disease is an important aspect of the green industry. Being able to prevent disease is, of course, the best defense, but changing conditions can leave some plants susceptible, such as the change to winter. Here are some ways to best manage disease in the winter.

Healthy Plants Resist Disease

The best way to avoid disease is to start with a healthy plant. If you’ve done all the right things to prepare plants for the winter, they'll be more robust. Preventing and managing plant disease begins before you even put anything in the ground with site preparation and plant selection.

Diagnosing Disease

Diseased plants often don’t look normal. That’s your first clue that a plant may not be healthy. To properly diagnose plant problems, you’ll need to understand some key things like general knowledge of the plant, the current environment, and the most common diseases or other problems to which the plant is vulnerable.

With this information, you are likely to make a more informed diagnosis. An inaccurate diagnosis could lead to unneeded pesticide treatment, wasted time, extra costs, and further deterioration of the plant.

Disease Is a Response

Plant diseases are considered a response to some kind of continuous irritation by an infectious element. A disease can then present itself in symptoms where the plant won’t yield, reproduce, or grow as expected.

The most common causes of disease are biotic (or “living”). This is different than abiotic disorders, which are caused by nonliving elements. Understanding the difference between the two is critical to proper diagnosis.

Conditions That May Lead to Disease

Plant diseases offer valuable clues to the conditions from which the issue arose. It’s first a good idea to review all the conditions the plant was introduced to. These problems could include an improper site, nutrient imbalance, water stress, or mulching, irrigation or pruning practices that are incorrect.

In many cases, when you identify and address the conditions, you can then make a correction so the disease doesn’t take over, ultimately offering the plant the ability to regain its health and strength.

Strategies for Disease Management

There are several different strategies you can initiate to manage disease. One is an integrated pest management (IPM), which places the most emphasis on cultural practices and plant selection. Pesticides are a last resort with this strategy.

Another strategy is to manage diseases by understanding symptoms. First, it’s ideal to know the difference between symptoms and signs. Symptoms result from the plant’s response to infection. There are a variety of symptoms with the most common being chlorosis, leaf lesions, and abnormal plant tissues.

Signs, however, are the indicators of the pathogen or pest, which is responsible for the symptoms. Signs of a pathogen may include:

  • Mold on the plant surface
  • Spores
  • Pycnidia
  • Bacterial ooze

With a clear understanding of symptoms versus signs, you are more likely to make an accurate diagnosis and then respond with appropriate treatment.

This strategy is more reactive than prevention-oriented, but it may be a more precise way to manage disease, especially if you have a large operation and a variety of plants.

A third strategy would be to use pesticides uniformly. This means that you aren’t looking for symptoms. You are just treating the whole based on what that plant may be the most vulnerable to. You’ll have to consider the cost of treating all plants and decide if the pesticide presents any other concerns.

What Changes in Winter?

When winter comes, plants are becoming dormant. Many plants have been placed in the ground in the fall for a spring arrival. When you are planting in the fall, you have to also think about how disease might try to attack during dormancy or even before then.

Thus, the most crucial thing you can do is to make sure they are planted well and ready for what the winter will bring. The site needs to be prepped properly and all best practices for watering, sunlight, and nutrition should be followed.

If your plant has had the chance to take root and thrive then it’s less likely to get infected during the winter. Plants basically hibernate in the winter. They need energy from the right soil and moisture before they go to sleep.

Plants that have not found their right way into the ground may not have the strength to fend off diseases. If the soil isn’t rich with nutrients or there are too many plants too close together, they may be more vulnerable.

That is why planning means so much in landscaping. You can’t expect that conditions will be perfect all the time but there are usually things you can do that give your plants the best chance to grow and bloom once spring arrives.

Disease management is not a perfect science. You can do all the things right and still end up with a diseased plant. Keep your chances of a good yield by prepping for the right conditions, checking for symptoms, and treating as soon as possible.

We hope you have a bounty this spring, and if you’re looking for a better way to reach more landscaping customers, check out LandscapeHub’s online marketplace.