May is when tomato season starts feeling real. Seedlings are finally in the ground, temperatures are warming up, and those small plants suddenly begin putting on growth almost overnight.

But May is also when tomato problems start showing up. One day your plants look healthy, and the next you notice curled leaves, yellowing stems, or spots spreading across lower branches. The good news is most May tomato problems are manageable if you catch them early.

Over the years, I’ve learned that tomatoes are surprisingly resilient. They just need the right balance of warmth, airflow, water, and support - especially during this transitional spring period. Here are the most common tomato problems gardeners face in May, and how to fix them before they affect your summer harvest.

Why Tomatoes Struggle in May

Tomatoes are adjusting to several things at once in May, like stronger sunlight, fluctuating temperatures, and inconsistent spring rain. Even healthy plants can look unhappy for a week or two after transplanting.

One year, I planted tomatoes during an unusually warm stretch in early May, only to get hit with cold nighttime temperatures days later. The plants stalled completely for nearly two weeks before recovering. That experience taught me that May gardening is often about stability more than speed.

Problem #1: Yellow Leaves

Yellow leaves are probably the most common tomato complaint in May. Sometimes it’s harmless. Other times, it’s the plant signaling stress.

Common Causes

• overwatering

• poor drainage

• nitrogen deficiency

• cold soil

Lower leaves yellowing shortly after transplanting is fairly normal. But widespread yellowing usually points to watering or soil issues.

How to Fix It

A big improvement you can make for tomato health is to improve drainage. Raised beds, especially systems like those from Vego Garden, help regulate soil conditions much more consistently in spring. Tomatoes hate sitting in soggy ground, especially during cool nights.

I also avoid watering lightly every day. Deep watering a few times a week encourages stronger roots.

Problem #2: Curled Leaves

Leaf curl looks dramatic, but it’s often more cosmetic than dangerous. You’ll notice leaves folding upward or twisting slightly.

Common Causes

• transplant stress

• Inconsistent watering 

• strong winds

One windy May, nearly every tomato plant in my garden curled its leaves for a week. I thought disease had hit the entire bed. Turns out, the plants simply reacted to temperature stress and recovered once conditions stabilized.

What Helps

Try mulching around the base, water consistently, and avoid excessive pruning early on. Most important tip: don’t panic too soon.

Problem #3: Stalled Growth

Sometimes tomatoes just… stop growing. You expect explosive growth, but instead the plant sits there looking unchanged for days. Tomatoes love warmth, but May temperatures can still swing dramatically between day and night. If nighttime temps consistently dip below 50°F, plants often slow down to conserve energy for later.

How to Encourage Growth

I’ve found three things usually help:

• warm soil

• steady moisture

• early support structures

Installing tomato cages or supports early also prevents plants from redirecting energy later after becoming tangled or damaged.

Trellises and tomato supports help keep young plants upright and improve airflow right from the start of the season.

Problem #4: White or Pale Leaves

This is often caused by sunscald from skipping hardening off. Indoor-grown seedlings need gradual exposure to outdoor sunlight. Otherwise, leaves can bleach or burn after transplanting.

I made this mistake years ago with a tray of heirloom tomatoes I was particularly proud of. I placed them directly into full sun on a warm afternoon and watched the leaves fade almost white by evening. Now, I always harden seedlings off slowly over about a week before planting outdoors.

Problem #5: Drooping Plants 

This one confuses gardeners because the plants often recover at night. In many cases, temporary wilting during hot afternoons is normal - especially during rapid growth in spring. But if the soil stays wet and plants continue drooping overnight, root stress may be involved.

What Helps

• watering deeply in the morning

• mulching

• avoiding overwatering

Tomatoes actually perform better with slightly drier conditions than constantly wet soil.

Problem #6: Spots on Leaves

May moisture and spring rain can trigger fungal issues. Lower leaves close to wet soil are usually affected first.

I now remove the lowest tomato leaves once plants are established. It improves airflow and prevents soil splash during rainstorms. Vertical supports also help tremendously, because they keep foliage lifted and organized without getting crowded near damp ground.

The Importance of Tomato Support 

One thing newer gardeners underestimate is how quickly tomatoes grow once summer approaches.

Installing cages, towers, or trellises in May can help prevent stem breakage, improve airflow, and reduce disease too. I used to wait until plants “needed support,” which usually meant wrestling giant stems into awkward cages later. Now I install supports immediately after planting and let the tomatoes grow naturally into them.

A Real Garden Scenario

One spring, I planted tomatoes in two different areas: one in heavy ground soil and another in raised beds with proper spacing and support

After several weeks of spring rain, the difference was dramatic. The raised bed tomatoes stayed healthier, greener, and grew faster because the soil drained properly and the airflow remained better. That was the season I fully committed to raised beds. 

FAQs

Should I prune tomatoes in May?

Light pruning is fine, especially lower leaves touching soil, but avoid heavy pruning too early while plants are still establishing.

How often should I water tomatoes in spring?

Deep watering two to three times a week is usually better than shallow daily watering.

Is leaf curl always a problem?

No. Mild leaf curl is often caused by weather stress and usually resolves on its own.

When should I install tomato supports?

As early as possible—ideally right after planting.

Final Thoughts

May is a learning month for tomato gardeners. Plants are adjusting, the weather is often unpredictable, and small issues can appear quickly. But most tomato problems are also signals.

Once you learn how tomatoes respond to temperature, moisture, and airflow, you start spotting issues early and correcting them before they affect the harvest. Some of the best tomato growers I know aren’t the ones with perfect gardens. They’re the ones who’ve spent time troubleshooting problems to understand how tomatoes grow.