When to Plant Sweet Potatoes in Los Angeles County, CA
May in the garden — Los Angeles County, California
Your Los Angeles County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
-
Sow sweet potatoes in trays indoors
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.
Los Angeles County, California is in USDA Zone 10b. The average last spring frost is April 3 and the first fall frost is November 21, giving you a growing season of approximately 232 days.
At an elevation of 1,315 feet, Los Angeles County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Sweet Potatoes during the growing season. With low rainfall, drip irrigation is essential for growing Sweet Potatoes successfully. Mulch heavily to conserve soil moisture.
Los Angeles County Soil Profile
Soil Type
Loam
Soil pH
5.8-7.5
Drainage
Well Drained
Plant 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 Los Angeles County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (5.8–7.5) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Los Angeles County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sweet Potatoes
Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sweet Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Oct | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Nov | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Los Angeles County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sweet Potatoes 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 Potatoes Planting Timeline — Los Angeles County, CA
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 20 | Feb 20 – Mar 6 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Harvest | July 10 | Jul 10 – Aug 28 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 10b
📆 Growing Season
232 days in Los Angeles County
Growing Tips for Sweet Potatoes in Los Angeles County
Direct sow Sweet Potatoes outdoors after April 03 in Los Angeles County when soil has warmed and frost danger has passed.
Los Angeles County receives only 13" of rain annually. Sweet Potatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Los Angeles County, CA?
Los Angeles County is in Zone 10b with an average last frost of April 3. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Los Angeles County, CA?
Los Angeles County, California is in USDA Hardiness Zone 10b. The average last spring frost is April 3 and first fall frost is November 21.
Your Los Angeles County Garden Planner — Free
A 24-page printable planner built for Los Angeles County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.