How to keep tomato plants alive (the four mistakes to avoid)
What ruins tomato plants and what to do about each problem before it becomes terminal.
Sera Mendel
February 15, 2026
Mistake 1: Watering wrong
Tomatoes want deep, infrequent watering — 1–2 inches per week, all at once. Shallow daily watering creates weak roots.
Water the soil, not the leaves. Wet leaves invite blight (the disease that turns leaves brown and kills tomato plants).
Mistake 2: Skipping mulch
A 2-inch layer of straw or wood chips around the base keeps soil moisture even, suppresses weeds, and prevents soil splash onto leaves (which spreads disease).
Mulch is the single most underrated tomato move. It cuts watering work in half.
Mistake 3 & 4: Pruning and support
Prune suckers — the small shoots growing from the joint between stem and branch. They take energy without producing fruit.
Stake or cage early, before the plant is heavy. A leaning plant is a fragile plant.
People also ask
How much sun do tomatoes need?+
8 hours of direct sun is ideal. 6 hours is the minimum for any decent harvest.
Why are my leaves turning yellow at the bottom?+
Often normal — plant is shedding lower leaves as it grows up. Concerning if it spreads up the plant fast (could be disease).
When do tomatoes ripen?+
65–80 days from transplanting, depending on variety. Cherry varieties ripen sooner than beefsteak.