When to Plant Runner beans in Des Plaines, Illinois, United States

Step by step in Des Plaines

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.

Start indoors

12-26 Apr

Two weeks before your last frost, under cover or on a windowsill.

Sow direct

3-17 May

One week after your last frost.

Plant out

3-17 May

One week after your last frost.

Harvest

2-22 Jul

Frost tolerance

Tender

Damaged below

0°C (32°F)

Days to maturity

60–80

Min soil temp

12°C (53.6°F)

Spacing

20 cm

Sowing depth

40 mm (1.6 in)

Sun

Full

Runner beans through the year

Against the frost risk in Des Plaines

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Runner beans

Frost risk Start indoors Sow direct Plant out Harvest Today

Seasonal context

Rainfall and the growing season in Des Plaines

May has the highest average precipitation (121 mm); January has the lowest (44 mm). Compare this pattern with the planting windows and your water supply.

Jan 44 mm

Feb 51 mm

Mar 63 mm

Apr 94 mm

May 121 mm

Jun 112 mm

Jul 100 mm

Aug 105 mm

Sep 87 mm

Oct 91 mm

Nov 58 mm

Dec 58 mm

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 Des Plaines

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.

NASA POWER climate averages, 1995–2024
Month	Average low	Average high	Frost days
January	-9.8°C (14.4°F)	-1.5°C (29.3°F)	29.4
February	-8.2°C (17.3°F)	1.1°C (33.9°F)	26.6
March	-2.4°C (27.6°F)	7.7°C (45.9°F)	23.1
April	2.6°C (36.7°F)	14.5°C (58.1°F)	8.7
May	8.8°C (47.8°F)	20.7°C (69.3°F)	0.3
June	14.7°C (58.5°F)	26.3°C (79.3°F)	0.0
July	17.6°C (63.8°F)	28.7°C (83.6°F)	0.0
August	17.2°C (63°F)	28.3°C (83°F)	0.0
September	12.9°C (55.2°F)	24.7°C (76.4°F)	0.0
October	5.9°C (42.7°F)	17°C (62.6°F)	3.2
November	-0.7°C (30.7°F)	8.4°C (47.2°F)	18.0
December	-6.3°C (20.6°F)	1.4°C (34.5°F)	27.5

For runner beans, 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 runner beans for Des Plaines

May is the wettest month in the rainfall grid, averaging about 121 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 runner beans

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.
Harden off plants raised indoors: gradually expose them to outdoor light, wind and temperature before their final move into the bed.
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.

Put the climbing structure in place before sowing

Install a strong frame before the roots and stems spread. Place plants where the frame will not shade shorter crops and where you can reach both sides for picking.

Keep water available as flowers and pods develop, especially in dry weather. Poor pod set can reflect conditions around flowering; it is not automatically a reason to add more fertiliser.

Pick pods young and often before they become fibrous. Letting many pods develop mature seeds changes the plant's priorities and reduces the value of a tender-pod harvest.

Growing in a container

Use a generous, stable container with a firmly anchored climbing frame, or choose a dwarf variety. Tall beans and light pots are a poor match for an exposed balcony.

What to record this season

How did watering and weather around flowering relate to pod set? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.

Further reading: RHS runner beans growing guide . 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 guide is written for UK growing conditions. Use its cultivation advice with local cultivar and seasonal guidance; its calendar months are not worldwide recommendations.

How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy

Why these dates

Install a strong frame before the roots and stems spread. Place plants where the frame will not shade shorter crops and where you can reach both sides for picking.

Protect tender growth from frost and wait for suitable growing warmth. The catalog cold-damage figure is a reference, not a guarantee: duration, wind, plant age and acclimatisation affect damage.

This calendar uses frost-relative offsets as a starting point. Runner beans are timed from 2 weeks before that frost for an indoor start, with planting out 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Des Plaines.

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.

The median frost-free season here is 179 days, against 60 to 80 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.

See every crop timed for Des Plaines →

Nearby

Runner beans in places close by

Mount Prospect 6 km Arlington Heights 10 km Skokie 12 km Palatine 15 km Evanston 16 km Hoffman Estates 16 km

Also in Des Plaines

Other vegetables to time

Tomatoes tender Lettuce half hardy Potatoes half hardy Courgettes tender Sweet peppers tender Carrots hardy Cucumbers tender Green beans tender Peas hardy Garlic very hardy Chilli peppers tender Sweetcorn tender

Growing runner beans in Des Plaines

Can I grow runner beans in Des Plaines?

The calendar estimates a planting window, not a guarantee of success. May is the wettest month in the rainfall grid, averaging about 121 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 runner beans in Des Plaines?

Aim for 3-17 May in an average year. If you would rather not gamble on the weather, wait until 19 May - 2 Jun - by then frost has finished in nine years out of ten.

When might runner beans be ready to harvest in Des Plaines?

The estimated period is 2-22 Jul, based on 60 to 80 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 runner beans tolerate?