Fertilizer Calculator

Get personalized, practical fertilizer recommendations based on what you're growing, how big it is, and whether it's in the ground or a container.

1. What are you growing?

Heavy feeder — requires consistent nutrition for high yields.

2. Growing method

3. Growth stage

4. Physical size (more precise)

Choose the option that best matches your situation.

Recommendations for Vegetables

In-Ground

Finished Compost

1–2 inches around the plant or 1–2 gallons per plant per application

essential

When: At planting + annually in spring or fall

The foundation of healthy plants. Improves soil structure and feeds microbes. Apply 1–3 inches as a top-dress or mix into planting hole.

Most “fertilizer problems” are actually soil problems. Compost fixes the root cause.

Blood Meal

1–2 tbsp per plant

high

When: At planting + side-dress every 4–6 weeks

Excellent for leafy growth early in the season.

Most vegetables are heavy nitrogen feeders during vegetative growth.

Bone Meal

1–2 tbsp per plant

high

When: At planting, worked into the root zone

Especially important for tomatoes, peppers, and root crops.

Supports strong roots and fruit development.

Kelp / Seaweed Meal

1 tbsp per plant

medium

When: When flowering begins, then every 4–6 weeks

Improves fruit quality and stress resistance.

Potassium is critical once plants start flowering and setting fruit.

Synthetic Alternatives (Secondary Options)

Balanced Granular (10-10-10 or 5-5-5)

Follow package rates — Early spring (and mid-season for vegetables)

Use only if you do not have good organic matter in the soil.

Bloom Booster (5-10-10 or 10-30-20)

Follow label rates for your plant size — When plants begin flowering

Switch to this after good vegetative growth is established.

For best results, get a soil test before applying significant amounts of any fertilizer. Many nutrient problems are actually pH or soil structure issues that fertilizer alone cannot fix.

These are general guidelines based on common horticultural practices. A soil test is the best way to know exactly what your soil needs.

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