Preventing Tomato Blight in Reused Containers: Sanitation Steps

Last year's container tomatoes had blight. Same soil in pots. Asks what to add to stop blight.

Do Not Reuse the Soil

Blight pathogens (Phytophthora, Alternaria) overwinter in soil and plant debris. Discard all old potting mix.

Sanitize Pots

1. Empty pots.
2. Scrub with stiff brush.
3. Soak 10 min in 10% bleach solution (1 part bleach : 9 water).
4. Rinse thoroughly.

Fresh Start Protocol

• New, sterile potting mix.
• Disease‑resistant varieties ('Defiant', 'Mountain Magic', 'Iron Lady').
• Water at soil level (drip/soaker) — keep leaves dry.
• Morning watering only.
• Mulch to prevent soil splash.
• Rotate—don't plant tomatoes in same spot yearly.
• Don't over‑fertilize (high N increases susceptibility).

Clean pots + new soil + resistant varieties + dry leaves = best blight defense.