When to plant Cosmos in Sharp County, AR
In Sharp County, plant Cosmos in spring between March 19 and April 9, once soil temps hold above 50°F. Sharp County's last frost averages March 26, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 60–90 days before the first frost on November 2.
When to Plant Cosmos in Sharp County, AR
July in the garden — Sharp County, Arkansas
Welcome to July in Zone 7b. These are the moves that will have the biggest impact on your growing season.
-
Start harvesting cosmos
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Get ahead of August
- First harvests: cosmos
Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.
Sharp County, Arkansas is in USDA Zone 7b. The average last spring frost is March 26 and the first fall frost is November 2, giving you a growing season of approximately 221 days.
At an elevation of 674 feet, Sharp County receives approximately 50.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cosmos during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.
Sharp County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-7
Drainage
Well Drained
Cosmos 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 Sharp County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (5.3–7.0) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Sharp County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Cosmos.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Aug 04 to harvest before frost.
Cosmos Water Budget
Monthly Watering Guide for Cosmos
Cosmos 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 | Cosmos Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Sharp County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos 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.
Cosmos Planting Timeline — Sharp County, AR
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | March 19 | Mar 19 – Apr 2 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Bloom | May 28 | May 28 – Oct 1 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
221 days in Sharp County
Growing Tips for Cosmos in Sharp County
Direct sow Cosmos outdoors after March 26 in Sharp County when soil has warmed and frost danger has passed.
Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Sharp County, AR?
Sharp County is in Zone 7b with an average last frost of March 26. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sharp County, AR?
Sharp County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 26 and first fall frost is November 2.
When should I plant Cosmos in Sharp County, AR?
In Sharp County, AR, plant Cosmos after the last frost (around March 26) and before the first frost (around November 2). Best results when soil holds above 50°F.
What growing zone is Sharp County, AR for Cosmos?
Sharp County sits in USDA Zone 7b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Sharp County's climate?
Yes — Cosmos grows well in Sharp County's temperate climate. Sharp County averages a 221-day frost-free season, with last frost around March 26 and first frost around November 2.
Your Sharp County Garden Planner — Free
A 22-page printable planner built for Sharp 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.