Climate-based cauliflower planting guide for Mount Vernon, Washington

When to Plant Cauliflower in Mount Vernon: Timing and Maturity Guide

Cauliflower is usually an easy fit in Mount Vernon. The season is generally not the hard part, so gardeners can focus more on quality, consistency, and harvest timing.

Typical Planting Window

Excellent fit in this climate

Use the planting dates below for cauliflower in Mount Vernon.

Start indoors February 10
Typical planting window March 10 – March 24
Method Transplant
Typical days to maturity 65–85

Gardeners usually start indoors around February 10 and plant outdoors from about March 10. Most varieties need about 65–85 days to reach maturity once they are in the garden.

Cauliflower is usually an easy seasonal fit in Mount Vernon. The more useful question is how to turn that margin into better sizing, steadier growth, and a cleaner finish.

Even in an easier climate, this crop still pays back uninterrupted growth. The season helps with maturity, but it does not erase the effects of checks that reduce sizing or finish quality.

Best local strategy: Use the normal planting window, avoid growth checks, and keep moisture and spacing consistent so the crop sizes evenly.

Can Cauliflower Mature in Mount Vernon?

Growing degree days measure how much useful warmth typically accumulates during the season. For cauliflower, this helps estimate whether local heat accumulation is usually enough for the crop to reach maturity on time.

Available GDD (base 40) 3878
Typical crop GDD target 1000
Heat margin +2878

From the usual planting window, Mount Vernon typically provides about 3878 growing degree days for cauliflower. With a typical crop target of 1000, that leaves a heat margin of +2878. That large heat margin means the crop usually has no trouble reaching maturity here. In practice, planting timing mostly affects how comfortably the crop sizes up and when harvest is ready, not whether the crop can finish.

GDD Checkpoints for Mount Vernon

If planting later than usual, this table shows how much growing degree day heat is still available from each point in the season. For cauliflower, it is most useful for judging how much freedom you still have to plant for quality, finish, and harvest goals as the season moves along.

Checkpoint Remaining GDD Heat margin Fit vs typical target
Apr 15 3802 +2802 Comfortable
May 1 3631 +2631 Comfortable
May 15 3438 +2438 Comfortable
Jun 1 3144 +2144 Comfortable
Jun 15 2876 +1876 Comfortable
Jul 1 2553 +1553 Comfortable

Best Cauliflower Varieties for Mount Vernon

In Mount Vernon, early and mid-season cauliflower varieties are usually the best fit in a typical year. Slower choices can still work when gardeners want their specific qualities and do not give away margin through delay.

Varieties that often fit well here include:

Variety class Typical days to maturity Typical GDD need Local fit
Early 60–70 900 Good fit
Mid-season 70–85 1000 Good fit

Main risk: The usual setbacks here come from management choices rather than from the season itself.

How Frost Affects Cauliflower in Mount Vernon

Mount Vernon usually has about 224 frost-free days, with a typical last spring frost around March 24 and a typical first fall frost around November 3.

Typical last spring frost March 24
Typical first fall frost November 3
Typical frost-free days 224
Minimum safe temperature 28°F / -2 °C

Cauliflower is generally lightly frost tolerant and temperatures below about 28°F ( -2 °C) can slow growth or damage plants.

Cauliflower is usually tolerant enough of cool conditions that light frost is not the main concern. The more useful question is how early planting affects establishment and overall crop quality.

The most common problems here are not climatic ones. Gardeners usually lose ground through timing, uneven growth, or letting the crop move past its best stage.

In Mount Vernon, cauliflower usually has a solid seasonal margin when planted around March 17. Local gardens do not all warm and cool at the same pace. The warmest garden spots are usually south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards tend to warm up later and usually provide less heat. For cauliflower, warmer garden spots usually improve early growth and can make timing a little more forgiving.

Related crops

Related crops worth comparing for the same city:

For a broader local overview, see the Mount Vernon planting guide. You can also use the Growing Degree Day Planner to test planting dates and crop timing.