When to Plant Lettuce in Wheaton, Illinois, United States

Step by step in Wheaton

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

15-29 Mar

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

Sow for autumn

19 Jul - 9 Aug

Counting back 74 days from your first frost so the crop matures in time.

Sow direct

5-19 Apr

Three weeks before your last frost.

Plant out

12-26 Apr

Two weeks before your last frost.

Harvest

20 May - 4 Jun

Sow in succession. A single sowing gives you a single glut. Sow a short row every 10 days through the window above and you get a steady supply instead.

Frost tolerance

Half-hardy

Damaged below

-3°C (26.6°F)

Days to maturity

45–60

Min soil temp

4.5°C (40.1°F)

Spacing

25 cm

Sowing depth

6 mm (0.2 in)

Sun

Partial

Lettuce through the year

Against the frost risk in Wheaton

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Lettuce

Frost risk Start indoors Autumn sowing Sow direct Plant out Harvest Today

Seasonal context

Rainfall and the growing season in Wheaton

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 Wheaton

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 lettuce, 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 lettuce for Wheaton

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 lettuce

Use the calendar to plan ahead, then check the conditions in your own garden.

Measure the soil at sowing depth. Aim for at least 4.5°C (40.1°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.

Choose loose leaves or a whole head before sowing

Lettuce has shallow roots. Keep the seedbed evenly moist, then check it regularly in dry weather; a dry surface can stop emergence even when deeper soil remains damp.

Heat and water stress encourage bolting and bitter leaves. In a hot season, compare locally suitable varieties and a cooler position instead of assuming that any frost-free week is suitable.

Sow modest batches so that the crop does not all mature together. Record which variety and sowing produced usable leaves before the weather changed.

Growing in a container

Loose-leaf types are useful in containers. Leave room to reach individual plants and keep drainage clear; a small pot needs frequent moisture checks.

What to record this season

Which sowing gave usable leaves before bolting, and was it a head or leaf harvest? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.

Further reading: RHS lettuce 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

Lettuce has shallow roots. Keep the seedbed evenly moist, then check it regularly in dry weather; a dry surface can stop emergence even when deeper soil remains damp.

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. Lettuce are timed from 6 weeks before that frost for an indoor start, with planting out 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Wheaton.

The median frost-free season here is 179 days, against 45 to 60 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 Wheaton →

Nearby

Lettuce in places close by

Naperville 10 km Schaumburg 19 km Bolingbrook 19 km Hoffman Estates 20 km Aurora 21 km Elgin 24 km

Also in Wheaton

Other vegetables to time

Tomatoes tender 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 lettuce in Wheaton

Can I grow lettuce in Wheaton?

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 lettuce in Wheaton?

Aim for 5-19 Apr in an average year. If you would rather not gamble on the weather, wait until 21 Apr - 5 May - by then frost has finished in nine years out of ten.

When might lettuce be ready to harvest in Wheaton?

The estimated period is 20 May - 4 Jun, based on 45 to 60 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 lettuce tolerate?