When fungal diseases appear in your garden, it can be confusing to know which treatment is the right one. You might notice black spots on your roses, mildew on your zucchinis, or rust on your lawn and head straight to the shelves for a fungicide. But then comes the tricky part – should you choose a contact fungicide or a systemic fungicide?
Many home gardeners struggle with this decision, often picking one at random or relying on trial and error. The result? Wasted money, frustrated effort, and plants that don’t recover as well as they could. Understanding the difference between these two types of fungicides is key to protecting your plants effectively and keeping your garden healthy year-round.
This guide will break it down in simple terms so you can make the best choice for your plants.
What Are Fungicides?
What is a Contact Fungicide?
What is a Systemic Fungicide?
Key Differences Between Contact and Systemic Fungicides
When to Use Contact vs. Systemic Fungicides
Best Practices for Effective Fungicide Use
Fungicides are products designed to control fungal diseases that affect plants. They don’t just improve the look of your garden – they also protect crops and ornamentals from serious damage that can reduce yields, kill plants, or spread disease across your entire garden.
Contact fungicides stay on the surface of the plant. When fungi spores land on the treated surface, they are killed before they can infect the plant tissue.
Provide a protective barrier against infection.
Work quickly once applied.
Lower risk of fungi developing resistance.
Need to be reapplied regularly, especially after rain.
Only protect the parts of the plant that are sprayed – missed spots are vulnerable.
Systemic fungicides are absorbed into the plant’s tissues and move throughout its system. This means they don’t just sit on the surface but protect the plant from the inside out.
Longer-lasting protection compared to contact fungicides.
Can stop early infections that have already entered plant tissue.
Often require fewer applications.
More expensive than contact fungicides.
Risk of fungi developing resistance if overused.
May take longer to show results.
| Feature | Contact Fungicide | Systemic Fungicide |
|---|---|---|
| How it works | Stays on plant surface, kills spores on contact | Absorbed into plant tissue, protects from within |
| Duration of protection | Short-term, needs frequent reapplication | Long-term, fewer applications needed |
| Resistance risk | Low | Higher if overused |
| Best use | Preventing new infections | Treating existing infections and long-term protection |
Use contact fungicides when you want to prevent fungal spores from infecting healthy plants, particularly in wet or humid conditions.
Use systemic fungicides when you need to treat plants already showing signs of infection or want longer-lasting protection.
Rotate between contact and systemic fungicides to reduce resistance.
Always follow the label instructions carefully.
Apply early in the morning or late afternoon to avoid leaf burn.
Make sure to cover all plant surfaces evenly.
At Garden Nursery Products, we provide a wide range of fungicides – both contact and systemic – to suit every type of garden and crop. Whether you’re looking to prevent diseases on your roses, treat powdery mildew on your vegetables, or protect your lawn, we’ve got trusted solutions from leading brands. Explore our range of fungicides today. Visit our store or shop online.
