Basil care guide: when & how to prune, fertilize and spray
Ocimum basilicum · USDA zones 10–11
Warm-season annual herb. Plant after frost danger, pinch often for bushy plants, and remove flowers to keep the leaves coming.
☀️ Sun
Full sun.
💧 Water
Even moisture; water at the base.
🪱 Soil
pH 6.0–7.0. Rich, well-drained. Compost.
How and when to prune basil
Pinch and harvest
When: 5–6 weeks after the last spring frost, then every 2 weeks (6 times a season).
- zones 8–10: about Apr 1–8
Pinching above a leaf pair makes two new shoots and delays flowering.
- Pinch each stem just above the second or third pair of leaves.
- Pinch off flower spikes as soon as they appear.
Fertilizing basil
Liquid feeding
When: 4–5 weeks after the last spring frost, then every 4 weeks (3 times a season).
- zones 8–10: about Mar 25 – Apr 1
Frequent harvests deplete nitrogen.
- Water with fish emulsion or half-strength liquid fertilizer.
What to use: 🌿 Fish emulsion or fish/seaweed blend (e.g. Neptune's Harvest)
Other care for basil
Plant out after frost
When: 2–4 weeks after the last spring frost.
- zones 8–10: about Mar 11–25
Basil is damaged by temperatures below 50°F/10°C.
- Plant once nights stay above 50°F/10°C, 12 in (30 cm) apart.
Common basil problems and how to fix them
Basil downy mildew
Signs: Yellow leaves with gray-purple fuzz underneath.
What to do: Pull and bag infected plants. Choose resistant varieties (e.g. 'Prospera'). Water early in the day.
Basil care FAQ
When should I prune basil?
Pinch and harvest: 5–6 weeks after the last spring frost (around Apr 1–8 in zones 8–10). Warm-season annual herb. Plant after frost danger, pinch often for bushy plants, and remove flowers to keep the leaves coming.
What is the best fertilizer for basil?
Frequent harvests deplete nitrogen. Good options: Fish emulsion or fish/seaweed blend (e.g. Neptune's Harvest).
What soil does basil need?
Rich, well-drained. Preferred pH 6.0–7.0. Compost.
How much sun and water does basil need?
Sun: Full sun. Water: Even moisture; water at the base.
What are common basil problems?
Basil downy mildew: Yellow leaves with gray-purple fuzz underneath. Pull and bag infected plants. Choose resistant varieties (e.g. 'Prospera'). Water early in the day.
More herbs care guides
Timings are given relative to your average frost dates, with examples for typical US climates. Always read and follow product labels.