When to Plant Sweet Alyssum in McClain County, OK
Your June gardening checklist
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
-
Start harvesting sweet alyssum
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
A few tasks this June that'll pay off in July
- First harvests: sweet alyssum
Sweet Alyssum (Lobularia maritima) is a low-growing cool-season annual prized for its honey-scented clusters of tiny white, pink, or purple flowers. A workhorse border plant, it tolerates light frost, self-seeds readily, and attracts beneficial insects throughout its bloom season. In warm climates it often re-blooms in fall after summer heat fades.
McClain County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 5, giving you a growing season of approximately 217 days.
At an elevation of 558 feet, McClain County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Sweet Alyssum during the growing season.
McClain County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.8
Drainage
Well Drained
Sweet Alyssum 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 McClain County
How your county's soil matches Sweet Alyssum's growing requirements.
Soil pH
Your soil pH (6.4–7.8) overlaps with Sweet Alyssum's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in McClain County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Sweet Alyssum.
How to Plant Sweet Alyssum
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Succession Planting Sweet Alyssum
Sow every 5.1 weeks. Last sowing by Sep 06 to harvest before frost.
For a dedicated fall crop, sow by Sep 24.
Sweet Alyssum Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sweet Alyssum
Sweet Alyssum 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 | Sweet Alyssum Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Nov | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in McClain County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Alyssum 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.
Sweet Alyssum Planting Timeline — McClain County, OK
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | April 2 | Apr 2 – Apr 16 |
| Direct Sow | March 5 | Mar 5 – Mar 26 |
| Bloom | May 14 | May 14 – Aug 20 |
| Fall Sowing | September 24 | Sep 24 – Oct 8 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
217 days in McClain County
Growing Tips for Sweet Alyssum in McClain County
Direct sow Sweet Alyssum outdoors after April 02 in McClain County when soil has warmed and frost danger has passed.
Your generous 217.0-day season in McClain County allows multiple plantings of Sweet Alyssum. Sow every 22.0 days for continuous harvest.
Common pests for Sweet Alyssum in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
McClain County receives only 23" of rain annually. Sweet Alyssum needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Surface-sow seeds — they need light to germinate. Direct-sow as soon as soil can be worked in spring; in zones 7+ also sow in fall. Thin to 6 inches apart. Shear back hard in midsummer when heat causes dormancy — plants recover and re-bloom when cool weather returns. Self-seeds prolifically; allow a few plants to set seed for a perpetual colony.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Sweet Alyssum in Other Locations
Frequently Asked Questions
When should I plant Sweet Alyssum in McClain County, OK?
McClain County is in Zone 7b with an average last frost of April 2. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is McClain County, OK?
McClain County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 5.
Your McClain County Garden Planner — Free
A 22-page printable planner built for McClain 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.