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When to Plant Mitsuba in Ascension Parish, LA

Mitsuba (Japanese parsley) is a shade-loving herb with trefoil leaves and a mild celery-parsley flavor. It is essential in Japanese cuisine for soups, salads, and garnishes.

Ascension Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.

At an elevation of 226 feet, Ascension Parish receives approximately 61.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103ยฐF, so Mitsuba may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Mitsuba will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mitsuba root diseases.

Ascension Parish, LA (Zone 9a) Year-round
295 days
Last Spring Frost February 13
295 growing days
First Fall Frost December 5

Ascension Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (191 days to spare)
Start indoors: Jan 7 Transplant: Jan 28 🍅 Harvest: Mar 25 – May 20
Recommended (50%) ✓ Fits season (190 days to spare)
Start indoors: Jan 16 Transplant: Feb 6 🍅 Harvest: Apr 3 – May 29
Safe Start (90%) ✓ Fits season (179 days to spare)
Start indoors: Feb 11 Transplant: Mar 4 🍅 Harvest: Apr 29 – Jun 24

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Mitsuba needs ~1,635 GDD — county provides 8,066 GDD Excellent fit

Mitsuba Planting Timeline โ€” Ascension Parish, LA

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 โ€“ Jan 30
Transplant Outdoors February 6 Feb 6 โ€“ Feb 20
Direct Sow January 23 Jan 23 โ€“ Feb 13
Fall Sowing October 10 Oct 10 โ€“ Oct 24
Harvest April 3 Apr 3 โ€“ May 29

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March โ€”
April Harvest
May Harvest
June โ€”
July โ€”
August โ€”
September โ€”
October Fall Sowing
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

295 days

Growing Tips for Ascension Parish

Direct sow or start indoors in partial shade. Mitsuba prefers cool, moist conditions. Harvest outer stems as needed. Self-sows readily in shaded garden areas.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Mitsuba in Ascension Parish, LA?

Ascension Parish is in Zone 9a with an average last frost of February 13. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ascension Parish, LA?

Ascension Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 5.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ascension Parish gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Ascension Parish, LA. Local conditions may vary. Last updated: April 2026.