When to Plant and Harvest Asparagus
Long-lived perennial producing tender spring spears for 20+ years once established
Soil pH: Target soil pH 6.8. Lime if a soil test reads below 6.2. Keep it within 6.2 to 7.0. Soil Test Desk
Pets: Not on the ASPCA list. Garden asparagus is not listed by species. ASPCA lists asparagus fern, an ornamental relative, as toxic. Its berries can cause stomach upset. Pet-Safe Garden Finder
Best Time and Place to Plant Asparagus
In USDA zone 7, the typical spring window is March 10 to April 10. Cooler zones usually plant later; warmer zones plant earlier.
Plant Asparagus in a spot with 6+ hours of direct sun, soil warmed to 50F to 80F, and enough room for 18 inches between plants and 48 inches between rows.
Planting Windows by Zone
| Zone | Spring | Fall |
|---|---|---|
| Zone 1 | May 10 to May 31 | Spring only |
| Zone 2 | May 1 to May 25 | Spring only |
| Zone 3 | April 20 to May 15 | Spring only |
| Zone 4 | April 10 to May 10 | Spring only |
| Zone 5 | April 1 to May 1 | Spring only |
| Zone 6 | March 20 to April 20 | Spring only |
| Zone 7 | March 10 to April 10 | Spring only |
| Zone 8 | March 1 to April 1 | Spring only |
| Zone 9 | February 15 to March 20 | Spring only |
| Zone 10 | February 1 to March 10 | Spring only |
| Zone 11 | January 15 to February 28 | Spring only |
| Zone 12 | January 1 to February 15 | Spring only |
| Zone 13 | January 1 to February 1 | Spring only |
Spacing and Care
- Planting depth: 6 inches deep
- Spacing: 18 inches apart, 48 inches between rows
- Soil temperature: 50F to 80F
- Sunlight: 6+ hours
- Watering: 1-2 inches per week; reduce after harvest season
- Days to harvest: 730
Fertilization
- 10-10-10 Balanced synthetic: 2 lbs per 100 sq ft each spring
- Compost organic: 3-4 inches as annual top dressing
- Bone Meal organic: 2 lbs per 100 sq ft for phosphorus
Companion Plants
- Tomatoes
- Parsley
- Basil
- Marigold
Avoid Planting Near
- Onions
- Garlic
- Potatoes
Check any pair, and see which pairings have research behind them, on the Companion Planting Desk.
Harvest Signs
- Spears are 6-8 inches tall and 0.5 inch thick
- Tip scales are tightly closed
- Harvest in year 3 (limited) or year 4 (full season)
- Snap or cut at ground level; stop when thin spears dominate
Track picks and rate the season on the Harvest Log.
FAQs
When should I plant Asparagus?
Asparagus planting depends on your USDA hardiness zone. In USDA zone 7, the typical spring window is March 10 to April 10. Cooler zones usually plant later; warmer zones plant earlier.
What is the best time of year to plant Asparagus?
The best time of year to plant Asparagus is when your zone planting window is open and soil temperatures are around 50F to 80F. In USDA zone 7, the typical spring window is March 10 to April 10. Cooler zones usually plant later; warmer zones plant earlier.
Where is the best place to plant Asparagus?
Plant Asparagus in a spot with 6+ hours of direct sun, soil warmed to 50F to 80F, and enough room for 18 inches between plants and 48 inches between rows.
How far apart should I plant Asparagus?
Plant Asparagus about 18 inches apart, with rows around 48 inches apart.
What grows well with Asparagus?
Asparagus is commonly paired with Tomatoes, Parsley, Basil, Marigold.
How long does Asparagus take to grow?
Asparagus is typically ready to harvest in about 730 days under good conditions. Use the harvest signs below rather than the calendar alone.
How do I know when to harvest Asparagus?
Harvest Asparagus when spears are 6-8 inches tall and 0.5 inch thick. Tip scales are tightly closed Harvest in year 3 (limited) or year 4 (full season)