When to plant Comfrey in Davis, CA
In Davis, Comfrey is a single-season spring crop — there's no second fall window. Plant February 16–March 2 for an 60–90-day harvest, finishing well before the December 3 first frost.
When to Plant Comfrey in Davis, CA
Your July gardening checklist
Each item below is timed to Yolo County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Davis, California is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.
At an elevation of 163 feet, Yolo County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Comfrey may need afternoon shade and extra watering during peak heat.
Davis Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
Drainage
Well Drained
Comfrey 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 Davis
How your county's soil matches Comfrey's growing requirements.
Soil pH
Your soil pH (6.7–7.8) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Yolo County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Comfrey.
How to Plant Comfrey
Succession Planting Comfrey
Sow every 6.9 weeks. Last sowing by Sep 04 to harvest before frost.
Comfrey Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Comfrey
Comfrey needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Comfrey Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Mar | 4.3" | 4" | 0.3" | 💧 Light watering |
| Apr | 4.3" | 2.3" | 2" | 💧 Light watering |
| May | 4.3" | 0.8" | 3.5" | 🚿 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" | 0.3" | 4" | 🚿 Regular watering |
| Oct | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Nov | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Dec | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Yolo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Comfrey 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.
Comfrey Planting Timeline — Davis, CA
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Harvest | April 20 | Apr 20 – Jun 29 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
297 days in Yolo County
Growing Tips for Comfrey in Davis
Direct sow Comfrey outdoors after February 09 in Yolo County when soil has warmed and frost danger has passed.
General growing tips
Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Comfrey in Other Locations
When should I plant Comfrey in Davis, CA?
In Davis, CA, plant Comfrey after the last frost (around February 9) and before the first frost (around December 3). Best results when soil holds above 50°F.
What growing zone is Davis, CA for Comfrey?
Davis sits in USDA Zone 9b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in Davis's climate?
Yes — Comfrey grows well in Davis's temperate climate. Davis averages a 298-day frost-free season, with last frost around February 9 and first frost around December 3.
Your Yolo County Garden Planner — Free
A 22-page printable planner built for Yolo 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.