When to Plant Broccoli in Louisville, Kentucky (40299)
Location
Louisville, Kentucky
ZIP Code
40299
USDA Zone
7a
Last Frost
Friday, April 10, 2026
📅 Planting Calendar
Pro Tip: Start Broccoli seeds indoors 6 weeks before your last frost date, then transplant outdoors around Friday, April 10, 2026.
🌿 Plant Details
☀️ Growing Requirements
☀️
Sun
Full Sun (6 hours)
💧
Water
Regular (1-1.5 inches/week)
↔️
Spacing
18" apart
🌱
Planting Depth
0.5" deep
Seeds typically germinate in 4-7 days
Ready to Plant Broccoli in Louisville?
Get your seeds now so they're ready by Friday, February 27, 2026.
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Common Broccoli Varieties
Popular cultivars to look for at your local nursery or seed supplier.
Calabrese
Italian heirloom producing a large central head followed by abundant side shoots.
Belstar
Compact hybrid with blue-green domed heads; excellent heat tolerance.
Romanesco
Stunning lime-green fractal spirals with a mild, nutty flavor; technically a cross between broccoli and cauliflower.
Purple Sprouting
Overwintering variety that produces masses of small purple florets in early spring.
Common Broccoli Problems
What to watch for — and how to fix it before it spreads.
Pests
Velvety green caterpillar that chews large holes in leaves and heads; white butterflies lay eggs on plants.
Apply Bt at first sign; use row covers from transplanting; check undersides of leaves for eggs.
Light green looping caterpillar similar in damage to cabbageworm; holes in heads reduce market quality.
Bt spray; row covers; spinosad for heavy infestations.
Dense gray waxy colonies deep in broccoli heads are very difficult to remove after harvest.
Check undersides of leaves weekly; strong water jet; neem oil early in the season.
Hundreds of tiny holes in seedling leaves; rarely fatal but stresses transplants.
Row covers on transplants; kaolin clay spray; healthy transplants usually outgrow the damage.
Diseases
V-shaped yellow lesions at leaf margins with black veins; seed-borne bacterial disease.
Use certified seed; avoid overhead irrigation; destroy infected plants; rotate annually.
Soil-borne slime mold causes massive root deformation (clubs) and stunted, wilting plants.
Raise soil pH to 7.0–7.2 with lime; do not plant brassicas in affected beds for 7+ years.
Yellow angular patches on upper leaves with purple-gray spores beneath; thrives in cool, wet conditions.
Improve airflow; plant resistant varieties; apply copper fungicide preventively.
Common Mistakes
Broccoli needs 6–8 weeks of cool weather to form heads; heat causes buttoning (tiny premature heads).
Transplant 4–6 weeks before last spring frost; aim for heads to mature before summer heat.
Broccoli heads open into yellow flowers within days of reaching peak size.
Harvest when head is fully formed, tight, and deep green; before any yellow color develops in the buds.
After cutting the main head, most varieties produce side shoots for weeks — but only if the main head is removed.
Cut main head promptly, leaving the plant in the ground; side shoots will appear within 1–2 weeks.
🌾 Seed Saving Guide
🔴 DifficultWhen to Harvest Seed
Allow side shoots to flower fully after main head harvest. Harvest seed pods when tan and dry.
Processing
Thresh dried pods in a bag, winnow seeds from pod fragments.
Seed Viability
Up to 5 years when stored cool, dark, and dry.
Pro Tip
B. oleracea — crosses with all oleracea crops (kale, cabbage, cauliflower, kohlrabi). Isolate by 1000 feet.
Raised Bed Planting Guides
A 4×8 bed fits 14 plants of Broccoli. See plant counts, spacing grids, and companion pairings for every bed size →
Frequently Asked Questions
When should I plant Broccoli in Louisville, Kentucky? +
In Louisville (Zone 7a), start Broccoli seeds indoors around Friday, February 27, 2026 and transplant outdoors around Friday, April 10, 2026.
What is the last frost date for Louisville, Kentucky? +
The average last spring frost date for Louisville, Kentucky (ZIP 40299) is around Friday, April 10, 2026. This is based on NOAA climate normals for USDA Zone 7a.
How long does Broccoli take to grow? +
Broccoli typically matures in about 60 days from transplanting. In Louisville, that means you can expect harvest around Friday, April 10, 2026 plus 60 days.
Should I start Broccoli indoors or direct sow in Kentucky? +
Broccoli should be started indoors 6 weeks before your last frost date. In Louisville, that means starting around Friday, February 27, 2026.
Other Plants for Louisville
Growing Broccoli in Zone 7a
Broccoli (Brassica oleracea var. italica) is a popular garden vegetable. In Louisville, Kentucky, which is in USDA Hardiness Zone 7a, you should start seeds indoors around Friday, February 27, 2026.
Your average last frost date is Friday, April 10, 2026. Plan to transplant your Broccoli seedlings outdoors around Friday, April 10, 2026, about 0 weeks after your last frost date.