When to plant Sweet Alyssum in Santa Cruz County County,
Santa Cruz County County sits in USDA Zone 9b. Plant Sweet Alyssum between December 10 (after last frost on February 11) and December 31. A second sowing from September 25 to October 9 extends the harvest into fall.
When to Plant Sweet Alyssum in Santa Cruz County, CA
Your June game plan for Santa Cruz County, California
Welcome to June in Zone 9b. These are the moves that will have the biggest impact on your growing season.
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.
Santa Cruz County, California is in USDA Zone 9b. The average last spring frost is February 11 and the first fall frost is December 4, giving you a growing season of approximately 296 days.
At an elevation of 353 feet, Santa Cruz County receives approximately 18.3 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Sweet Alyssum during the growing season. With low rainfall, drip irrigation is essential for growing Sweet Alyssum successfully. Mulch heavily to conserve soil moisture.
Santa Cruz County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
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 Santa Cruz County
How your county's soil matches Sweet Alyssum's growing requirements.
Soil pH
Your soil pH (6.4–7.7) overlaps with Sweet Alyssum's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Santa Cruz County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). 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 05 to harvest before frost.
For a dedicated fall crop, sow by Sep 25.
Sweet Alyssum Water Budget
Water stress score is 8/10 — 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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| May | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Oct | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Nov | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Dec | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Santa Cruz 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 — Santa Cruz County, CA
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | January 7 | Jan 7 – Jan 21 |
| Direct Sow | December 10 | Dec 10 – Dec 31 |
| Bloom | February 11 | Feb 11 – May 13 |
| Fall Sowing | September 25 | Sep 25 – Oct 9 |
· 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 · Only during dry spells
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
296 days in Santa Cruz County
Growing Tips for Sweet Alyssum in Santa Cruz County
Direct sow Sweet Alyssum outdoors after February 11 in Santa Cruz County when soil has warmed and frost danger has passed.
Your generous 297.0-day season in Santa Cruz 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.
Santa Cruz County receives only 18" 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 Santa Cruz County, CA?
Santa Cruz County is in Zone 9b with an average last frost of February 11. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Santa Cruz County, CA?
Santa Cruz County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 11 and first fall frost is December 4.
When should I plant Sweet Alyssum in Santa Cruz County County, ?
In Santa Cruz County County, , plant Sweet Alyssum after the last frost (around February 11) and before the first frost (around December 4). Best results when soil holds above 50°F.
What growing zone is Santa Cruz County County, for Sweet Alyssum?
Santa Cruz County County sits in USDA Zone 9b. Sweet Alyssum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Sweet Alyssum grow in Santa Cruz County County's climate?
Yes — Sweet Alyssum grows well in Santa Cruz County County's temperate climate. Santa Cruz County County averages a 297-day frost-free season, with last frost around February 11 and first frost around December 4.
Your Santa Cruz County Garden Planner — Free
A 22-page printable planner built for Santa Cruz 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.