When to Plant Sweet Alyssum in Dimmit County, TX
Your June gardening checklist
A quick June briefing for Dimmit County, Texas gardeners — what's urgent, what's next, and what can wait.
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.
Dimmit County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is December 1, giving you a growing season of approximately 278 days.
At an elevation of 2,638 feet, Dimmit County receives approximately 63.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Sweet Alyssum during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Alyssum root diseases.
Dimmit County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.3
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 Dimmit County
How your county's soil matches Sweet Alyssum's growing requirements.
Soil pH
Your soil pH (6.5–7.3) is within Sweet Alyssum's preferred range (6.0–7.5).
Soil Texture
The loam soil in Dimmit County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Sweet Alyssum.
How to Plant Sweet Alyssum
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Sweet Alyssum
Sow every 5.1 weeks. Last sowing by Oct 02 to harvest before frost.
For a dedicated fall crop, sow by Sep 22.
Sweet Alyssum Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2" | 0.2" | 💧 Light watering |
| Mar | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 11.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2" | 0.2" | 💧 Light watering |
| Dec | 2.2" | 1.4" | 0.8" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Dimmit 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 — Dimmit County, TX
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | January 29 | Jan 29 – Feb 12 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Bloom | March 5 | Mar 5 – Jun 18 |
| Fall Sowing | September 22 | Sep 22 – Oct 6 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Transplant Outdoors |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9a
📆 Growing Season
278 days in Dimmit County
Growing Tips for Sweet Alyssum in Dimmit County
Direct sow Sweet Alyssum outdoors after February 26 in Dimmit County when soil has warmed and frost danger has passed.
Your generous 279.0-day season in Dimmit 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.
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 Dimmit County, TX?
Dimmit County is in Zone 9a with an average last frost of February 26. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dimmit County, TX?
Dimmit County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is December 1.
Your Dimmit County Garden Planner — Free
A 22-page printable planner built for Dimmit County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.