When to Plant Yarrow in Johnston County, OK
June in Johnston County, Oklahoma — your action list
We've pulled the most time-sensitive tasks for Johnston County, Oklahoma this June and put them front and centre. Tackle them in order.
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Harvest yarrow as they ripen
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in July — start thinking about
- First harvests: yarrow
Achillea millefolium (Yarrow) is a tough, drought-tolerant native perennial with aromatic finely-divided foliage and broad flat-topped flower clusters that serve as a landing platform for hundreds of beneficial insect species. Available in white (the species type) and a wide range of cultivars spanning yellow, gold, pink, salmon, and deep red. Spreads by rhizome to form ground-covering colonies; blooms from late spring through midsummer with reblooming into fall if deadheaded. Exceptional in hot, dry sites where other perennials fail.
Johnston County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.
At an elevation of 700 feet, Johnston County receives approximately 32.9 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Yarrow during the growing season.
Johnston County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.3
Drainage
Well Drained
Yarrow 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 Johnston County
How your county's soil matches Yarrow's growing requirements.
Soil pH
Your soil pH (6.3–7.3) overlaps with Yarrow's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Johnston County is excellent for Yarrow — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Yarrow will thrive.
How to Plant Yarrow
Succession Planting Yarrow
Sow every 6.9 weeks. Last sowing by Aug 13 to harvest before frost.
Yarrow Water Budget
Monthly Watering Guide for Yarrow
Yarrow 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 | Yarrow Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Nov | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Johnston County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Yarrow 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.
Yarrow Planting Timeline — Johnston County, OK
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 28 | Jan 28 – Feb 11 |
| Transplant Outdoors | March 25 | Mar 25 – Apr 8 |
| Direct Sow | March 18 | Mar 18 – Apr 8 |
| Bloom | May 27 | May 27 – Oct 21 |
· 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | 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 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
231 days in Johnston County
Growing Tips for Yarrow in Johnston County
Direct sow Yarrow outdoors after March 25 in Johnston County when soil has warmed and frost danger has passed.
Common pests for Yarrow in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8–10 weeks before last frost; seeds need light for germination — press onto soil surface, do not cover. Direct sow after last frost or divide established clumps in spring or fall. Thrives in poor, well-drained soil — rich soil and high fertility cause floppy stems and reduce flower count. Avoid overwatering; excellent drought tolerance once established. Deadhead spent clusters to encourage rebloom. Divide every 2–3 years to prevent center die-out and control spread. Year 2+ plants bloom most heavily; first-year plants may produce limited flowers. Dried flowers retain color well for arrangements.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Yarrow in Other Locations
Frequently Asked Questions
When should I plant Yarrow in Johnston County, OK?
Johnston County is in Zone 8a with an average last frost of March 25. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnston County, OK?
Johnston County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 11.
Your Johnston County Garden Planner — Free
A 22-page printable planner built for Johnston County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.