How Often to Fertilize Tomatoes? Complete Feeding Schedule

Growth Stage	Fertilizer Type	Frequency
Seedling (first 2 weeks)	None needed	-
Young plant (weeks 3-6)	Balanced (10-10-10)	Every 2 weeks, half strength
Flowering	Low-N/High-P (5-10-10)	Weekly
Fruiting	Tomato-specific	Weekly

Fertilizing Schedule by Growth Stage

Weeks 1-2 after transplanting

Let plants establish. No fertilizer needed if using quality potting mix.

Weeks 3-4: Begin feeding

Start with balanced fertilizer (10-10-10) at half strength every 2 weeks.

When flowers appear

Switch to tomato-specific or high-phosphorus fertilizer (5-10-10). Begin weekly feeding.

During fruiting

Continue weekly liquid fertilizer. Consistent feeding supports continuous production.

Signs Your Tomatoes Need Fertilizer

Nutrient Deficiency Signs

Yellowing lower leaves (nitrogen)
Purple-tinged leaves (phosphorus)
Brown leaf edges (potassium)
Slow growth, small leaves
Few flowers or fruit

Over-Fertilizing Signs

Very dark green, lush leaves
Lots of foliage, few fruits
Leaf tip/edge burn
White salt crust on soil
Wilting despite moist soil

Pro Tips for Fertilizing Tomatoes

Water first: Never fertilize dry soil - always water first, then apply fertilizer

Morning application: Fertilize in the morning so plants can absorb nutrients during the day

Dilute liquid fertilizer: Half-strength more often is safer than full-strength less often

Add calcium: Include calcium to prevent blossom end rot, especially important in containers

Frequently Asked Questions

How often should I fertilize tomatoes in containers?

Fertilize container tomatoes every 1-2 weeks during the growing season with liquid fertilizer. Start 2 weeks after transplanting and continue through the harvest season. Container plants need more frequent feeding than ground plants because nutrients wash out with regular watering.

What type of fertilizer is best for tomatoes?

Use a balanced fertilizer (like 10-10-10) when plants are young, then switch to a low-nitrogen, high-phosphorus and potassium fertilizer (like 5-10-10) once flowering begins. Too much nitrogen during fruiting promotes leaves over fruit. Look for 'tomato' or 'vegetable' specific fertilizers.

Can you over-fertilize tomatoes?

Yes, over-fertilizing causes problems: too much nitrogen produces lush leaves but few fruits, salt buildup damages roots, and plants become more susceptible to pests and diseases. Signs of over-fertilizing include dark green leaves, leaf tip burn, wilting despite moist soil, and lots of foliage with few flowers.

When should I start fertilizing tomato seedlings?

Start fertilizing tomato seedlings 2-3 weeks after transplanting, or when the first true leaves appear if growing from seed. Use a diluted fertilizer (half strength) for young plants. Wait until plants are established before full-strength applications to avoid burning tender roots.

How Often to Fertilize Tomatoes?

Quick Answer