Cool Season Vegetables to Jump-Start Your Garden

Nature's fastest foods from field to table

After a long, cold and dreary winter, few things feel better than the warmth that starts to build in those early days of spring. The air takes on a new freshness, an aliveness, as plants start to wake up from their winter dormancy and birds and insects start ramping up their activities in those golden moments of spring sunshine.

What’s even more exciting is that this first flush of green is your cue that garden season is here! Well, at least if you know what to plant first.

Cool season vegetables are Nature’s version of fast food. These ambitious plants don’t need to wait for warm soil to start growing. And if you pick and choose your varieties right, you can be harvesting food in as little as 30 days. (Okay, now that I write that, Nature’s version of fast food is vastly different what happens in modern life - but perhaps that should give us some serious pause!)

Let’s take a look at the plants that are able to grow even in cool soils, and how you can get food onto your table in record time this spring.

Dandelion flowers are a sure sign of warming spring soils - and the plant is 100% edible! (Photo by Hendrik Roggemann on Unsplash)

What are cool season vegetables?

Cool season vegetables are plants that have a high tolerance for cold temperatures, can sprout even when the soil is cool, and many can survive a frost. That makes these cool season plants the best choice for early spring (or fall) planting.

While cool season plants can grow even when temperatures remain cool, it is important to know your plant families and the specific varieties that do best in these conditions.

Common traits of cool season vegetables:

• Can germinate in cool temperatures

• Usually direct seeded although some can be transplanted

• Fast maturing

• Many allow for partial harvesting

Fast Growing Cool Season Vegetables

You may be surprised at just how many plants fit into the category of cool season vegetables. Some plant families are nearly exclusively cool season plants, like the Brasssicas (Cabbage family). These are plants best started early, although you may be harvesting the results of those plantings well into the summer.

Other plant families only have one or two cool season members and the rest need warm soil and long days to grow. Think about the difference between potatoes and peppers! Potatoes do best planted very early (often as soon as the ground is workable) whereas peppers cannot germinate without warm soils and warm night time temperatures.

Here is a cool season plant chart by family to help you figure out what works best:

Vegetables you can start VERY early (Source: Sue Senger using Canva Pro)

One way to know for sure the soil is warm enough to direct seed these plants is to have a few perennial herbs growing in your garden as bioindicators. Great choices include thyme, oregano, chives, catnip, and yarrow. These plants start growing fast, often even before the leaves are out on the trees yet. And that is the whole point! We often don’t realize just how fast we can start gardening!

My go to spring “test” plants include mustards, arugula, kale, radish, and sometimes spinach. Essentially the Brassica family is the safest bet. I just go out and spread some seed into a patch and keep an eye on that. In fact, I’ll be doing this later today because I can see my perennial herbs are growing and I saw the very first dandelion blooming yesterday in a warm spot on the driveway.

I seed a patch of Brassicas and then WHEN these seeded plants start to grow, then I go ahead with other cool season crops. It’s like doing a soil temperature test without overcomplicating things. I let my garden give me the thumbs up to keep on planting before I potentially waste seed because I am being over-zealous.

It also means that if we do get a big cold snap (still possible well into April where I live), then I haven’t wasted too much effort too soon.

Of course the lure of seeded as soon as possible is fresh green food, straight from the garden. And the sooner food starts from the garden, the sooner the grocery store bill can start to decline. There is also the added benefit that the faster you start eating your own home-grown food in spring, the higher the health benefits for your year, because high quality food means better health.

If you are not sure how much you want to grow this year, then check out this post on how many pounds of vegetables makes sense to shoot for (read more here).

Don’t Get Confused By These Plants

And just to make it absolutely clear, here are the main vegetable warm season crops.

These crops all need warm soil to germinate (Source: Sue Senger using Canva Pro)

Common traits of warm season vegetables:

• Do not germinate in cool soil

• Direct seed or start early indoors with bottom heat and light

• Most have long growing season requirements

• Most have sustained harvesting windows (except the grasses and grains)

While you definitely won’t get anywhere direct sowing warm season crops in the garden when the leaves are not even out on the trees, it can be a good time to consider starting some indoors. Most of the warm season crops need bottom heat and good light to grow well indoors. They often become tall and leggy if started in just a window.

I usually start some of the hardier warm season vegetables about now. Tomatoes, zucchini, cucumbers and celery are good choices. While these plants need warm temperatures to start growing, in a few weeks they can usually be transferred outside into my little greenhouse to keep growing. That frees up space in my seed starting area for the true heat lovers - peppers, eggplants, melons and pumpkins. I sometimes start some sunflowers early so I will get flowers earlier. The rest I tend to wait and direct sow into the garden.

Cool Season Fast Food

The fastest growing cool season vegetable, hands down, are radishes. They germinate fast in cool soil and create a harvest in 30 days or less. Everything else takes anywhere from 30 to 60 days or more to reach mature harvest size.

That said, why wait? With lettuce, spinach, mustards, kale, arugula and other greens, I do one of two things. I either OVERPLANT THE SPACE (aka crowding) knowing that I will thin out the patch and use the thinnings as the first harvest. Or, I plant WAY TOO MUCH, knowing that I will rip out sections as early harvest and re-plant to some other vegetable. Both strategies work great for maximizing early yields. The way I am feeling this spring (after not being able to garden last spring due to a hand injury) - I am going to do BOTH this year LOL.

Today I think my plan will be to create a custom mix of my own spring seeds and use that to broadcast a patch of my garden where my chickens have done a marvelous job of turning the soil and clearing the space. This will let me test growing conditions and put food plants in where otherwise I will likely see weeds growing in short order. That’s a win-win for me.

What are your favorite cool season vegetables? Let me know in the comments.