When to Plant Cilantro in Delaware County, PA
Your May planting checklist for Delaware County, Pennsylvania
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Delaware County, Pennsylvania.
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Start cilantro under lights
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
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Start harvesting cilantro
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June will be here before you know it — start on
- First harvests: cilantro
Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.
Delaware County, Pennsylvania is in USDA Zone 7b. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.
At an elevation of 1,094 feet, Delaware County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cilantro during the growing season.
Delaware County Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.2
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Delaware County
How your county's soil matches Cilantro's growing requirements.
Soil pH
Your soil pH (5.0–6.2) is more acidic than Cilantro prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Delaware County is excellent for Cilantro — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Cilantro.
How to Plant Cilantro
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Cilantro
Sow every 4.6 weeks. Last sowing by Aug 25 to harvest before frost.
For a dedicated fall crop, sow by Aug 15.
Plant Water Budget
Monthly Watering Guide for Cilantro
Cilantro needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Cilantro Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.9" | 0" | ❄️ Dormant |
| Feb | — | 2.3" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Delaware County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cilantro Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Cilantro Planting Timeline — Delaware County, PA
Cilantro Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 12 | Mar 12 – Mar 26 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Direct Sow | April 2 | Apr 2 – Apr 23 |
| Harvest | May 21 | May 21 – Jul 23 |
| Fall Sowing | August 15 | Aug 15 – Aug 29 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
191 days in Delaware County
Growing Tips for Cilantro in Delaware County
Direct sow Cilantro outdoors after April 16 in Delaware County when soil has warmed and frost danger has passed.
Your generous 191.0-day season in Delaware County allows multiple plantings of Cilantro. Sow every 20.0 days for continuous harvest.
Common pests for Cilantro in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Cilantro in Other Locations
Frequently Asked Questions
When should I plant Cilantro in Delaware County, PA?
Delaware County is in Zone 7b with an average last frost of April 16. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.
What planting zone is Delaware County, PA?
Delaware County, Pennsylvania is in USDA Hardiness Zone 7b. The average last spring frost is April 16 and first fall frost is October 24.
Your Delaware County Garden Planner — Free
A 24-page printable planner built for Delaware County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.