How to Fertilize Beets for Root and Leaf Growth

Fertilizing beets correctly is all about balance. Give them too much nitrogen, and you’ll get lush greens but small roots. Too little nutrition, and both the roots and leaves will suffer. In my 30+ years of gardening in California’s Central Valley and Sonoma Valley, I’ve fine-tuned a fertilizing approach that consistently produces sweet, plump roots and healthy greens.

Table of Contents

Understanding Beet Nutritional Needs

Beets are light-to-moderate feeders that thrive in fertile, well-drained soil with a slightly acidic to neutral pH (6.0–7.0). They need:

Nitrogen (N): For healthy leaf growth, which supports photosynthesis and root development.
Phosphorus (P): Encourages strong root formation.
Potassium (K): Improves overall plant vigor and disease resistance.

An NPK ratio around 5-10-10 works well for root development without encouraging excess foliage.

Fertilizing Before Planting

1. Soil Test First

A simple soil test tells you what nutrients are lacking. This prevents over-fertilizing and balances nutrients from the start.

2. Pre-Plant Fertilizer Application

Work 2–3 inches of compost into the top 6 inches of soil.
Add a balanced organic fertilizer or one slightly higher in phosphorus and potassium.
Avoid fresh manure—it can cause forked or hairy roots.

Fertilizing During Growth

For Leaf and Root Balance

Side-dress with a low-nitrogen fertilizer (like 5-10-10) when plants are 4–6 inches tall.
If greens are pale, supplement with a quick nitrogen boost, such as fish emulsion, but apply sparingly.

Application Tips

Keep fertilizer 2–3 inches from the base of plants to avoid burning.
Water thoroughly after fertilizing to help nutrients reach the roots.

My Fertilizing Routine

When I plant beets in raised beds, I mix compost and a phosphorus-rich organic fertilizer into the soil before sowing. At about three weeks in, I side-dress lightly and water deeply. In the Central Valley’s heat, I often give an extra light feeding midway through the season to keep greens vibrant. In Sonoma Valley’s milder climate, one midseason feeding is usually enough.

Key Takeaways

Focus on phosphorus and potassium for root growth.
Avoid excess nitrogen—it leads to big greens, small roots.
Test soil before planting for best results.

With the right fertilizing approach, you’ll enjoy tender, sweet beets with nutrient-rich greens from the same plant.

Fertilizer Schedule for Beets by Growth Stage

Growth Stage	Time Frame (Weeks After Planting)	Fertilizer Type	NPK Ratio	Application Tips
Pre-Planting	0 (Before sowing seeds)	Compost + organic granular	5-10-10 or 4-6-6	Mix into top 6 inches of soil; avoid fresh manure.
Seedling Stage	3–4 weeks	Low-nitrogen granular or liquid	5-10-10	Side-dress 2–3 inches from base; water after application.
Midseason Growth	5–6 weeks	Balanced organic fertilizer	5-10-10 or 4-4-6	Apply lightly; avoid overfeeding nitrogen to prevent leafy excess.
Leaf Boost (Optional)	Anytime if leaves pale	Fast-acting nitrogen (fish emulsion)	~5-1-1	Dilute per label; apply sparingly to avoid stunted roots.
Late Season (Optional)	7–8 weeks before harvest	Compost tea or kelp extract	Low N, high K	Improves sweetness, flavor, and root firmness.