Collards · Des Plaines, Illinois, United States

When to plant collards in Des Plaines

Main outdoor window

12 Apr - 10 May

A climate estimate. Check your soil, forecast and cultivar.

Timed from last spring frost

26 April

In Des Plaines, on your chosen risk.

Ready to pick

1 Sep - 31 Mar

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 Des Plaines

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.

Start indoors

15 Mar - 12 Apr

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

Sow for overwintering

4-25 Jul

Counting back 89 days from your first frost so the crop matures in time.

Sow direct

12 Apr - 10 May

Two weeks before your last frost.

Transplant

12 Apr - 10 May

Two weeks before your last frost.

Harvest

1 Sep - 31 Mar

Frost tolerance
Very-hardy
Damaged below
-10°C (14°F)
Days to maturity
55–75
Min soil temp
7°C (44.6°F)
Spacing
45 cm
Sowing depth
12 mm (0.5 in)
Sun
Full

Collards through the year

Against the frost risk in Des Plaines

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

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

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
MonthAverage lowAverage highFrost 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 collards, 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 collards 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 collards

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

  • Measure the soil at sowing depth. Aim for at least 7°C (44.6°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.
  • 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.

Make space for repeated harvests of large leaves

Use a sunny position and amended, well-drained garden soil. A soil test is more useful than adding fertiliser by guesswork. Choose a slow-bolting cultivar if you want to extend leaf picking.

Pick leaves before they reach full size for a more tender texture, leaving the centre to grow. Inspect leaf undersides for pests and record which sowing season gives usable leaves before flowering begins.

What to record this season

At what leaf size was the texture best, and when did flowering begin? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.

Further reading: NC State Extension: Collards Group . 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.

This is regional US cultivation guidance. Variety recommendations and calendar months need a local check before use elsewhere.

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

Why these dates

Use a sunny position and amended, well-drained garden soil. A soil test is more useful than adding fertiliser by guesswork. Choose a slow-bolting cultivar if you want to extend leaf picking.

Cold tolerance varies with cultivar, plant age, acclimatisation and the duration of a freeze. A plant surviving frost does not mean its leaves, heads, flowers or developing crop will remain undamaged. Check the forecast and the variety's local advice.

This calendar uses frost-relative offsets as a starting point. Collards 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 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 55 to 75 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 →

Growing collards in Des Plaines

Can I grow collards 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 collards in Des Plaines?

Aim for 12 Apr - 10 May in an average year. If you would rather not gamble on the weather, wait until 28 Apr - 26 May - by then frost has finished in nine years out of ten.

When might collards be ready to harvest in Des Plaines?

The estimated period is 1 Sep - 31 Mar, based on 55 to 75 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 collards tolerate?

Cold tolerance varies with cultivar, plant age, acclimatisation and the duration of a freeze. A plant surviving frost does not mean its leaves, heads, flowers or developing crop will remain undamaged. Check the forecast and the variety's local advice.