When to plant Lobelia in Barnstable County, MA
Plant Lobelia in Barnstable County, between March 28 and April 11 — the only viable window. Zone 7a's short season (189 frost-free days) rules out a fall crop.
When to Plant Lobelia in Barnstable County, MA
What to do in June
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Barnstable County, Massachusetts.
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Fire up the seed-starting tray: lobelia
These need a head start before your last frost (April 18). Sow into cells now so you're ready to transplant in a few weeks.
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Basket week: lobelia
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Before July arrives, get these ready
- First harvests: lobelia
Lobelia (Lobelia erinus) is a cool-season annual prized for the intense cobalt blue that is rare among bedding flowers. It blooms most prolifically in spring and early summer but stalls or dies back during heat peaks above 90°F. In zones 3–7 it delivers a long display; in zones 8–9 it is best treated as a spring annual that fades by midsummer. Trailing types cascade beautifully from containers and window boxes.
Barnstable County, Massachusetts is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.
At an elevation of 518 feet, Barnstable County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Lobelia during the growing season.
Barnstable County Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.4
Drainage
Well Drained
Monthly Watering Guide for Lobelia
Lobelia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Lobelia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 3.1" | 0" | ❄️ Dormant |
| Mar | — | 4.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Barnstable County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lobelia Planting Timeline — Barnstable County, MA
Lobelia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 14 | Feb 14 – Feb 28 |
| Transplant Outdoors | March 28 | Mar 28 – Apr 11 |
| Bloom | May 23 | May 23 – Aug 15 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–80 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
189 days in Barnstable County
Growing Tips for Barnstable County
Start seeds indoors 10–12 weeks before last frost — seed is dust-fine and requires light to germinate; surface-sow and press gently. Keep at 65–70°F. Not reliably direct-sown. Transplant in cool weather, 2–4 weeks before last frost date is acceptable in zones 5+. Shear plants by one-third after the first bloom flush to encourage a second flush in fall. Provide afternoon shade in zones 7+ to extend bloom into summer.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lobelia in Other Locations
Frequently Asked Questions
When should I plant Lobelia in Barnstable County, MA?
Barnstable County is in Zone 7a with an average last frost of April 18. Plan your Lobelia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Barnstable County, MA?
Barnstable County, Massachusetts is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 24.
When should I plant Lobelia in Barnstable County, MA?
In Barnstable County, MA, plant Lobelia after the last frost (around April 18) and before the first frost (around October 24). Best results when soil holds above 50°F.
What growing zone is Barnstable County, MA for Lobelia?
Barnstable County sits in USDA Zone 7a. Lobelia grows reliably in zones 3a through 9b, so it's a good fit here.
Can Lobelia grow in Barnstable County's climate?
Yes — Lobelia grows well in Barnstable County's temperate climate. Barnstable County averages a 189-day frost-free season, with last frost around April 18 and first frost around October 24.
Your Barnstable County Garden Planner — Free
A 22-page printable planner built for Barnstable County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.