Dealing with Brown Stems on Your Tomato Plants

If you’ve noticed brown stems on your tomato plants, don’t panic! Brown stems are common and dealing with them doesn’t have to spell disaster for your crop. In this article, we’ll cover the causes of brown stems on tomato plants and give you some tips to get your plants healthy again.

What Causes Brown Stems on Tomato Plants?

There are a few potential culprits when it comes to brown stems on tomato plants:

• Blights – Both early blight and late blight fungus can cause brown spots and decay on tomato plant stems and leaves. These fungi thrive in cool, wet conditions.

• Wilt diseases – Fusarium wilt and Verticillium wilt fungi cause inner stem discoloration and wilting, They survive in soil so crop rotation is important

• Root initials – Harmless growths that look like roots may sprout on lower stems. They are actually root initials and are nothing to worry about.

• Pest damage – Insects may chew on stems leaving brown scars or openings for disease. Common offenders are cutworms, hornworms, or flea beetles.

• Environmental stress – Things like drought, flooding, or extreme temperatures can damage stems and leave them prone to infections.

• Herbicide injury – Chemical weedkillers like glyphosate can distort growth and cause strange root initials if tomatoes come in contact.

Taking Action for Brown Tomato Stems

If you see brown spots or oddly shaped stems on your plants, take these steps:

• Identify the cause – Look for patterns and clues like insects, wilting, or blighted leaves to pinpoint the culprit.

• Remove diseased plants – Pull up any plants with major brown rot on stems and throw them away or burn them. Don’t compost!

• Improve growing conditions – Give plants proper spacing, water, fertilizer, and mulch to avoid stress.

• Use preventative fungicides – Applying fungicides can help protect healthy plants from blights and wilt.

• Employ insect control – Stop pests like hornworms from chewing on stems by handpicking or using Bt spray.

• Ensure weedkillers don’t contact tomatoes – Keep glyphosate and other herbicides far from tomato plants.

When Brown Stems are Harmless

Sometimes brown spots or growths on tomato stems are not a major concern. Here are a few benign causes:

• Root initials – These small root-like projections won’t harm the plant. Just ensure soil moisture is even.

• Scars from pruning – It’s normal for pruned stems to turn brown as they heal. Monitor for disease infection.

• Minor physical damage – Accidental cracks or bruises won’t affect the plant much. Just keep an eye out.

• Older stem aging – Lower leaves and stems naturally turn brown and woody as the plant matures.

As long as damaged areas remain small and isolated, it is likely the plant will recover on its own. But keep an eye out for any spreading.

Preventing Brown Stems in the Future

While brown stems are common, you can take these proactive steps to avoid them in your garden:

• Select wilt-resistant tomato varieties when possible. Look for “VF” labeling.

• Disinfect tools between plants to avoid spreading blights.

• Use drip irrigation instead of overhead watering to keep foliage dry.

• Cover soil with plastic/organic mulch to suppress blight spores.

• Rotate tomato planting spots each year to disrupt soil fungi.

• Prune plants for better airflow and to remove diseased bits.

• Stake/cage plants to prevent injury from drooping and touching soil.

• Check underground stem and roots for borers/grubs that spread wilt fungi.

What To Do If Stems Stay Brown

If your tomato plant stems remain brown or new brown areas develop, the plant likely has a major fungal or wilt infection. At that point:

• Pull up and discard the plant immediately (don’t compost it).

• Avoid planting tomatoes, potatoes, peppers, or eggplants in that spot for 2-3 years.

• Sterilize tools, cages, and stakes with a 10% bleach solution before reuse.

• Remove and destroy all weeds, which may harbor blight fungi and wilt diseases.

• Solarize soil using clear plastic sheets to kill fungi and other pathogens.

By removing infected plants quickly and taking preventative biosecurity measures, you can stop the blight or wilt from spreading. Be vigilant and don’t give up too soon!

Common Questions about Brown Tomato Stems

Here are answers to some frequently asked questions about dealing with brown stems on tomato plants:

Should I cut off brown stems?

Only if they are small, isolated areas. Remove any larger brown sections by pulling up the whole plant.

Will my tomatoes be safe to eat if the plant has brown stems?

Tomatoes should be safe if brown stems are caused by stress or minor damage. Discard any fruit touching rotted stems.

Is it ok to compost tomato plants with brown stems?

No, the disease organisms could survive and spread. Burn diseased plants if possible or discard with household waste.

What causes hollow stems on tomatoes?

Hollow stems are most often caused by rapid growth spurts, but can also be a symptom of wilt diseases. Monitor hollow stems for further wilting.

Why are my tomato seedlings developing brown spots?

Damping off disease is common in young seedlings. Avoid overwatering and provide good air circulation to manage it.

Conclusion

Catching brown stems early and taking the proper corrective actions can help you stay on track for a productive tomato crop. Monitor plants closely for spreading issues and don’t hesitate to remove diseased plants. With preventative care and swift treatment, your other tomato plants can continue thriving and reward you with abundant ripe tomatoes!