When to Plant Sweet Alyssum in Webb County, TX
Your June game plan for Webb County, Texas
June is a pivotal month for Webb County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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.
Webb County, Texas is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 9, giving you a growing season of approximately 303 days.
At an elevation of 3,543 feet, Webb County receives approximately 50.9 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Sweet Alyssum may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Alyssum root diseases.
Webb County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
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 Webb County
How your county's soil matches Sweet Alyssum's growing requirements.
Soil pH
Your soil pH (6.6–7.7) overlaps with Sweet Alyssum's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Webb County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). 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 10 to harvest before frost.
For a dedicated fall crop, sow by Sep 30.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Mar | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 8.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 7.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Dec | 2.2" | 1.5" | 0.7" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Webb 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 — Webb County, TX
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | January 5 | Jan 5 – Jan 19 |
| Direct Sow | December 8 | Dec 8 – Dec 29 |
| Bloom | February 9 | Feb 9 – May 11 |
| Fall Sowing | September 30 | Sep 30 – Oct 14 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors |
| February | Bloom |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | Direct Sow |
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: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
303 days in Webb County
Growing Tips for Sweet Alyssum in Webb County
Direct sow Sweet Alyssum outdoors after February 09 in Webb County when soil has warmed and frost danger has passed.
Your generous 304.0-day season in Webb 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 Webb County, TX?
Webb County is in Zone 9b with an average last frost of February 9. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Webb County, TX?
Webb County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 9.
Your Webb County Garden Planner — Free
A 22-page printable planner built for Webb County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.