Agapanthus · Cicero, Illinois, United States
When to plant agapanthus in Cicero
Main outdoor window
11 May - 8 Jun
A climate estimate. Check your soil, forecast and cultivar.
Timed from last spring frost
4 April
In Cicero, on your chosen risk.
First flowers
1 Jul - 31 Aug
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 Cicero
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.
Plant the crowns
11 May - 8 Jun
Delayed by a soil-warming estimate derived from historical air temperatures. The frost-only date would be 11 Apr. Measure your soil before planting. This crop is never fully dormant, so it cannot be planted bare-root in winter.
In flower
1 Jul - 31 Aug
Agapanthus through the year
Against the frost risk in Cicero
Seasonal context
Rainfall and the growing season in Cicero
May has the highest average precipitation (119 mm); January has the lowest (47 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 Cicero
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 | -4.9°C (23.2°F)23.2°F (-4.9°C) | -0.2°C (31.7°F)31.7°F (-0.2°C) | 25.7 |
| February | -4.5°C (24°F)24°F (-4.5°C) | 0.8°C (33.5°F)33.5°F (0.8°C) | 23.6 |
| March | -0.5°C (31°F)31°F (-0.5°C) | 5.1°C (41.2°F)41.2°F (5.1°C) | 16.9 |
| April | 3.8°C (38.8°F)38.8°F (3.8°C) | 10°C (50°F)50°F (10°C) | 2.7 |
| May | 8.8°C (47.8°F)47.8°F (8.8°C) | 15.2°C (59.3°F)59.3°F (15.2°C) | 0.0 |
| June | 15.1°C (59.1°F)59.1°F (15.1°C) | 21.1°C (70°F)70°F (21.1°C) | 0.0 |
| July | 19.6°C (67.3°F)67.3°F (19.6°C) | 24.9°C (76.8°F)76.8°F (24.9°C) | 0.0 |
| August | 20°C (68.1°F)68.1°F (20°C) | 25.1°C (77.1°F)77.1°F (25.1°C) | 0.0 |
| September | 16.4°C (61.5°F)61.5°F (16.4°C) | 22°C (71.6°F)71.6°F (22°C) | 0.0 |
| October | 9.9°C (49.7°F)49.7°F (9.9°C) | 15.6°C (60°F)60°F (15.6°C) | 0.0 |
| November | 3.4°C (38.2°F)38.2°F (3.4°C) | 8.5°C (47.3°F)47.3°F (8.5°C) | 5.5 |
| December | -1.8°C (28.9°F)28.9°F (-1.8°C) | 2.7°C (36.8°F)36.8°F (2.7°C) | 18.4 |
For agapanthus, 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 agapanthus for Cicero
- May is the wettest month in the rainfall grid, averaging about 119 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 agapanthus
Use the calendar to plan ahead, then check the conditions in your own garden.
- Measure the soil at sowing depth. Aim for at least 12°C (53.6°F); the calendar estimates soil warmth from air temperatures and cannot measure your bed.
- Check the local overnight forecast before planting out. Delay planting or keep protection ready if frost is forecast, even after the historical last-frost date.
- Check mature size, drainage and cultivar suitability before choosing a permanent position. A suitable planting window does not guarantee long-term survival or fruiting.
Check evergreen or deciduous habit before planning winter care
Choose a labelled cultivar, suitable light and a drained root zone. Containers need room for healthy roots and regular moisture during growth; severe root congestion is not a dependable cure for poor flowering.
Keep evergreen foliage in suitable light if overwintering under cover. Dormant deciduous plants need different treatment. Division may temporarily reduce flowering, so record the timing and allow recovery rather than repeatedly repotting a newly divided clump.
What to record this season
Did the chosen winter treatment match the plant's evergreen or deciduous growth habit? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.
Further reading: Agapanthus (African Lily, Lily of the Nile) | North Carolina Extension Gardener Plant Toolbox . 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 reference describes plant identity and cultivation. Its regional calendar months and hardiness observations do not validate the calculated dates for another location. This reference covers the broader plant group; confirm the named form and its specific requirements with the supplier.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy
Why these dates
Choose a labelled cultivar, suitable light and a drained root zone. Containers need room for healthy roots and regular moisture during growth; severe root congestion is not a dependable cure for poor flowering.
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.
Agapanthus are planted once and then left in place, so there is no sowing offset to resolve. Nor is there a dormant season to plant into: this crop keeps its leaves and keeps growing through the winter, which is exactly why cold damages it. The window on this page therefore waits until the last frost in Cicero has passed and the soil has begun to warm, giving the roots the longest possible run before the cold returns.
Cicero sits in zone 7a, which is colder than the catalog range. Check a locally proven cultivar and a realistic protection plan before planting. The calculated dates do not confirm that this crop is suitable here. Check cultivar requirements and local growing experience before planting.
The general establishment guide is around year 2, under suitable conditions. This is not a prediction for this location; cultivar, winter conditions and care determine whether it flowers reliably.
Also in Cicero
Other flowers to time
Growing agapanthus in Cicero
Can I grow agapanthus in Cicero?
The calendar estimates a planting window, not a guarantee of success. May is the wettest month in the rainfall grid, averaging about 119 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 agapanthus in Cicero?
Aim for 11 May - 8 Jun in an average year. If you would rather not gamble on the weather, wait until 11 May - 8 Jun - by then frost has finished in nine years out of ten.
Can I plant agapanthus earlier in Cicero?
The historical frost estimate is 11 Apr. For Agapanthus, an air-temperature model estimates soil warmth of about 12°C (53.6°F) around 11 May. This is not a soil measurement or a forecast. Check your bed at sowing depth; cold, wet conditions can slow growth and increase decay risk.
When might agapanthus flower in Cicero?
The estimated period is 1 Jul - 31 Aug, based on 150 to 190 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 agapanthus 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.