When to Plant Geraniums in Tillman County, OK
Your June gardening checklist
Here's what deserves your attention in Tillman County, Oklahoma this month. Everything below is tailored to Zone 8a and timed around your local frost dates.
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Fire up the seed-starting tray: geraniums
These need a head start before your last frost (April 3). Sow into cells now so you're ready to transplant in a few weeks.
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Collect geraniums at their peak
If you can't use it all right away, check the food-preservation section of your planner.
Coming up in July — start thinking about
- First harvests: geraniums
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
Tillman County, Oklahoma is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is November 6, giving you a growing season of approximately 217 days.
At an elevation of 807 feet, Tillman County receives approximately 25.1 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Geraniums during the growing season.
Tillman County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.5
Drainage
Well Drained
Geraniums 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 Tillman County
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (6.2–7.5) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Tillman County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Geraniums.
How to Plant Geraniums
Succession Planting Geraniums
Sow every 8 weeks. Last sowing by Jul 29 to harvest before frost.
Geraniums Water Budget
Monthly Watering Guide for Geraniums
Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Geraniums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jul | 4.3" | 3.3" | 1" | 💧 Light watering |
| Aug | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Tillman County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Geraniums 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.
Geraniums Planting Timeline — Tillman County, OK
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 23 | Jan 23 – Feb 6 |
| Transplant Outdoors | March 27 | Mar 27 – Apr 10 |
| Bloom | June 5 | Jun 5 – Oct 23 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
217 days in Tillman County
Growing Tips for Geraniums in Tillman County
Direct sow Geraniums outdoors after April 03 in Tillman County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Geraniums in Other Locations
Frequently Asked Questions
When should I plant Geraniums in Tillman County, OK?
Tillman County is in Zone 8a with an average last frost of April 3. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Tillman County, OK?
Tillman County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is November 6.
Your Tillman County Garden Planner — Free
A 22-page printable planner built for Tillman 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.