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Yellow Leaves

Tomato Leaves Turning Yellow

Tomato yellowing is often a stress signal, not an instant sign that the plant is finished.

Look at which leaves changed first, how long the soil stays wet, and whether the plant recently faced cold nights or transplant shock. Those clues usually tell you more than the color alone.

Older leaves firstWet rootsCold setbacks

Next Move

Use the calendar when the real problem is timing or weather.

If the yellowing followed cold weather or a wet stretch, compare your recent lows and planting window in the calendar before changing fertilizer or spraying anything.

Problem Walkthrough

Check the pattern before you treat the plant

Keep the troubleshooting sequence simple: compare what you can see, rule out the most common causes, and choose the lowest-risk next step first.

Check First

  • Whether the oldest lower leaves yellowed first or the newest growth is paling too.
  • How damp the soil stays a full day after watering or rain.
  • Whether the plant was transplanted recently or hit a stretch of chilly nights.

Likely Causes

  • Overwatering that leaves roots slow, pale, and oxygen-starved.
  • Normal lower-leaf aging while the rest of the plant still looks vigorous.
  • Transplant stress or cool weather slowing nutrient uptake for a week or two.
  • Underfed container plants that have already used up the mix.

What To Do This Week

  • Let the top layer of soil dry slightly before watering again.
  • Remove only fully yellowed leaves so the plant keeps useful foliage.
  • Feed lightly if the plant is actively growing and the potting mix is exhausted.
  • Protect from another cold snap before making bigger changes.