As gardeners, we often think of pests and diseases as mid-summer headaches — but the truth is, many garden problems start early in the season. Whether you’re nurturing tender seedlings indoors or transplanting your first crops into the garden, staying ahead of pests and diseases in March, April, and May can make all the difference for a healthy, productive garden.
If you’re looking for 5 things to sow in march, check out our guide.
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At DBS Farm Wilson, we believe prevention is just as important as treatment — and we’re here to help you spot trouble early and stop it in its tracks.
Why Early-Season Pests and Diseases Matter
Newly emerged or recently transplanted plants are especially vulnerable to this gardening threat. Their tender leaves, delicate roots, and soft stems are prime targets for hungry insects and opportunistic fungi or bacteria. Addressing problems now ensures your plants establish strong roots and healthy growth, setting the stage for success all season long.
Common Early-Season Pests
1. Aphids
- What to Look For: Clusters of tiny green, black, or gray insects on new growth, curled leaves, or sticky residue (honeydew).
- Why They’re a Problem: Aphids suck sap from plants, weakening them and spreading diseases.
2. Flea Beetles
- What to Look For: Tiny black or bronze beetles that jump like fleas, along with pinprick holes in leaves — especially on brassicas like cabbage and kale.
- Why They’re a Problem: They damage young plants faster than they can recover.
3. Cutworms
- What to Look For: Seedlings mysteriously cut off at the soil line, usually overnight.
- Why They’re a Problem: These caterpillars chew through stems at ground level.
Common Early-Season Diseases
1. Damping Off (Seedling Rot)
- What to Look For: Seedlings suddenly collapse, often with mushy stems or water-soaked spots near the soil.
- Causes: Fungal pathogens thrive in overly wet or cool conditions.
2. Powdery Mildew
- What to Look For: White, powdery coating on leaves, especially in damp weather.
- Why It’s a Problem: It weakens plant tissues, stunts growth, and spreads quickly.
3. Root Rot
- What to Look For: Poor growth, wilting despite watering, and dark, mushy roots.
- Causes: Often linked to poor drainage, overwatering, or contaminated soil.
Preventing Powdery Mildew
Powdery mildew is a fungal disease that loves cool, humid air with poor airflow. It shows up as a white, powdery coating on leaves and spreads quickly if left unchecked.
Prevention Tips:
- ✅ Choose Resistant Varieties – When shopping for seeds, look for varieties labeled resistant to powdery mildew — especially for cucumbers, squash, and peas, (don’t make the same mistakes we did!).
- ✅ Space Plants Properly – Give plants room to breathe! Crowded plants trap moisture and humidity, which fungi love.
- ✅ Water at Soil Level – Avoid overhead watering, which wets leaves. Water early in the day so any splashes dry quickly.
- ✅ Prune for Airflow – Trim off excess foliage to allow air to circulate through plants, especially for tomatoes, squash, and cucumbers.
- ✅ Keep It Clean – Remove plant debris and weeds, which can harbor fungal spores over winter.
- ✅ Consider a Preventive Spray – For high-risk crops, organic sprays like neem oil, diluted milk spray (a home remedy), or sulfur-based fungicides can offer protection.
Preventing Seedling Rot (Damping Off)
Seedling rot is caused by fungal pathogens that thrive in cool, wet soil. It strikes seedlings at the soil line, causing them to collapse and die before they can even get going.
Prevention Tips:
- ✅ Start with Clean Tools & Trays – Always sanitize seed 1020 Trays, pots, and tools before planting. A 10% bleach solution works well.
- ✅ Use Sterile Seed-Starting Mix – Garden soil is too heavy and often carries disease spores. Use fresh, lightweight seed-starting mix every season.
- ✅ Avoid Overwatering – Keep soil moist, not soaked. Good drainage is key — never let trays sit in standing water.
- ✅ Provide Air Circulation – A small fan set on low near your seedlings helps keep air moving, reducing humidity and fungal risk.
- ✅ Don’t Overcrowd – Thin seedlings to avoid damp, crowded conditions where moisture lingers.
- ✅ Watch Temperature – Keep seed 1020 Trays in the recommended temperature range for your crops. Cold, wet soil is a breeding ground for rot.
How to Protect Your Garden with Prevention and Treatment
1. Inspect Early and Often
- Conduct routine checks every time you water or check your seedlings, inspect leaves (top and underside), stems, and soil for signs of insects, damage, or discoloration.
2. Practice Clean Gardening
- Use clean tools, 1020 Trays (our favorite), and pots when starting seeds.
- Avoid reusing contaminated soil — fresh seed-starting mix is worth the investment.
- Remove plant debris from garden beds to eliminate overwintering pests.
3. Encourage Beneficial Insects
- Ladybugs, lacewings, and parasitic wasps love to feast on aphids and other pests. Growing beneficial plants like alyssum, dill, and calendula can invite these natural helpers.
4. Physical Barriers
- Row covers block cutworms, flea beetles, and aphids, plus many more pests that come around in the summer. Highly recommend checking out our blog post on how to make and use row covers.
5. Adjust Watering & Airflow
- Avoid overwatering seedlings.
- Ensure good airflow in seed 1020 Trays and garden beds to reduce fungal risks.
6. Organic Sprays (As a Last Resort)
- Insecticidal soaps or neem oil can knock down aphids and flea beetles if populations explode.
- Copper-based fungicides can help with fungal diseases, but prevention is best.
Healthy Plants Fight Back!
Strong plants resist pests and diseases better. Start with healthy soil, feed appropriately, and choose disease-resistant varieties. At DBS Farm Wilson, we recommend organic compost, balanced fertilizers (our used and approved 20 20 20 fertilizer), and proven seeds to give your garden its best possible start.
Prevention is Always Easier than Treatment
Once these diseases take hold, they’re hard to stop — especially damping off, which has no cure. That’s why clean starts, careful watering, and good airflow are your first line of defense.
Pest and disease management isn’t just about reaction — it’s about building a resilient garden from the soil up. With careful observation, smart planning, and the right tools, you’ll keep your plants thriving through spring and into a bountiful harvest.
We hope you enjoyed this article on early-season gardening pests and diseases. If you did, make sure you check out the other growing guides, seed saving guides and our recipes. We are growing our website with more articles all the time, and we invite you to grow with us. Whether you’re a seasoned gardener or just starting out, gardening is an enriching experience. If you have any questions or want to share your journey, feel free to leave a comment below. Happy gardening!
