Larkspur · Fargo, North Dakota, United States
When to plant larkspurs in Fargo
Main outdoor window
11 Apr - 2 May
A climate estimate. Check your soil, forecast and cultivar.
Timed from last spring frost
9 May
In Fargo, on your chosen risk.
First flowers
10-30 Jul
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Fargo
Download these planting dates (.ics)
Import into Apple Calendar, Google Calendar or Outlook. Dates use the selected risk level and are planning estimates, not frost alerts.
Each window is a planning range. Check the forecast, soil and cultivar before planting; a later date is not automatically safer in hot or wet conditions.
Sow direct
11 Apr - 2 May
Four weeks before your last frost.
In flower
10-30 Jul
Larkspurs through the year
Against the frost risk in Fargo
Seasonal context
Rainfall and the growing season in Fargo
June has the highest average precipitation (104 mm); January has the lowest (14 mm). Compare this pattern with the planting windows and your water supply.
During wetter months, check that beds and containers drain after heavy rain. During drier months, plan how you will keep seeds and new transplants watered. Monthly averages can hide long dry spells and intense storms; they do not show soil moisture, humidity or this week's weather.
Source: NASA POWER, corrected MERRA-2 precipitation, 2001–2020. Values are approximate monthly totals, including the water equivalent of snow, from the nearest 0.5° × 0.625° grid cell. This reference period differs from the temperature record. Rainfall provides context and does not change the calculated planting dates. Method and limitations.
Monthly growing conditions in Fargo
Compare the planting window with the local temperature pattern. These are historical monthly averages, not this year's forecast or measured soil temperatures. Average frost days do not tell you whether a particular night will freeze.
| Month | Average low | Average high | Frost days |
|---|---|---|---|
| January | -17.6°C (0.4°F)0.4°F (-17.6°C) | -7.7°C (18.2°F)18.2°F (-7.7°C) | 30.9 |
| February | -15°C (5°F)5°F (-15°C) | -4.2°C (24.4°F)24.4°F (-4.2°C) | 27.9 |
| March | -6.9°C (19.5°F)19.5°F (-6.9°C) | 4.6°C (40.4°F)40.4°F (4.6°C) | 27.7 |
| April | -0.2°C (31.6°F)31.6°F (-0.2°C) | 13°C (55.4°F)55.4°F (13°C) | 15.6 |
| May | 7°C (44.5°F)44.5°F (7°C) | 20.4°C (68.7°F)68.7°F (20.4°C) | 2.1 |
| June | 13.3°C (55.9°F)55.9°F (13.3°C) | 25.8°C (78.5°F)78.5°F (25.8°C) | 0.0 |
| July | 16.2°C (61.2°F)61.2°F (16.2°C) | 29.1°C (84.4°F)84.4°F (29.1°C) | 0.0 |
| August | 14.9°C (58.9°F)58.9°F (14.9°C) | 28.3°C (83°F)83°F (28.3°C) | 0.0 |
| September | 10°C (50°F)50°F (10°C) | 23.2°C (73.7°F)73.7°F (23.2°C) | 0.2 |
| October | 2.3°C (36.1°F)36.1°F (2.3°C) | 13.7°C (56.6°F)56.6°F (13.7°C) | 10.0 |
| November | -5.2°C (22.7°F)22.7°F (-5.2°C) | 3.7°C (38.6°F)38.6°F (3.7°C) | 25.8 |
| December | -13.1°C (8.5°F)8.5°F (-13.1°C) | -4.7°C (23.5°F)23.5°F (-4.7°C) | 30.9 |
For larkspurs, also check drainage, sunlight and cultivar requirements. See the rainfall context above; humidity, irrigation and local pest pressure are not calculated.
Local growing check
Before choosing larkspurs for Fargo
- June is the wettest month in the rainfall grid, averaging about 104 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
The temperature and rainfall tables on this page show the underlying climate estimates. How these suitability checks work · Record what happens in your garden.
Before you plant larkspurs
Use the calendar to plan ahead, then check the conditions in your own garden.
- Measure the soil at sowing depth. Aim for at least 5°C (41°F); the calendar estimates soil warmth from air temperatures and cannot measure your bed.
- Frost tolerance does not make saturated or frozen soil suitable for planting. Wait until the bed can be worked without smearing or compacting it.
- Use the maturity range on your seed packet when choosing a variety. Cold, short days and transplant stress can make harvest later than the calendar estimate.
Grow annual larkspur for spikes rather than a permanent clump
Provide full sun and well-drained soil. The RHS describes both protected and outdoor seed raising; choose a method that fits your local season and transplant young plants carefully. Its UK sowing months are not a worldwide calendar.
For cut flowers, harvest spikes when the lowest buds have opened instead of waiting until the whole stem is at its peak. Leave selected plants to complete their display if border colour is the priority. Record the actual sowing-to-flower interval for the named strain rather than expecting an annual to return as a perennial crown.
What to record this season
When did the lowest buds open, and did the chosen strain give stems of a useful length? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.
Further reading: Consolida ajacis | giant larkspur . General crop guidance; local dates on this site are calculated separately. Source checked 19 September 2026 by Safe to Plant; this is not an expert review.
The RHS reference is written for UK growing conditions. Use its cultivation advice with local seasonal guidance; UK sowing months are not worldwide planting dates.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy
Why these dates
Provide full sun and well-drained soil. The RHS describes both protected and outdoor seed raising; choose a method that fits your local season and transplant young plants carefully. Its UK sowing months are not a worldwide calendar.
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.
This calendar uses frost-relative offsets as a starting point. Larkspurs are timed for direct sowing 4 weeks before it, and this page simply resolves those offsets against the frost date computed for Fargo.
The calendar also applies a soil-warming estimate derived from historical air temperatures. Where that estimate is later than the frost-based date, it delays the window. Soil in your own garden can warm earlier or later; a thermometer at sowing depth is a better final check. Cold, wet conditions can slow germination and increase decay risk.
Fargo is zone 4a, within the crop's general range. This is an initial cold-hardiness check; cultivar, exposure, drainage and unusual winters can still change the outcome.
The median frost-free season here is 152 days, against 90 to 110 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Fargo
Other flowers to time
Growing larkspurs in Fargo
Can I grow larkspurs in Fargo?
The calendar estimates a planting window, not a guarantee of success. June is the wettest month in the rainfall grid, averaging about 104 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
When should I plant larkspurs in Fargo?
Aim for 11 Apr - 2 May in an average year. If you would rather not gamble on the weather, wait until 18 Apr - 9 May - by then frost has finished in nine years out of ten.
When might larkspurs flower in Fargo?
The estimated period is 10-30 Jul, based on 90 to 110 days from the modeled planting date. Cultivar, planting material and growing conditions can change this interval; check the plant as well as the calendar.
How much frost will larkspurs tolerate?
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.