Arugula – the ideal cool weather leafy vegetable

Arugula or rocket lettuce is an ideal leafy vegetable for the colder times of the year. 

Before we even dream about growing tomatoes, carrots, or beans, arugula will thrive and quickly deliver wonderful flavors to any meal or salad.

Arugula to the rescue

When your garden beds are empty and crying out for something to do, luckily, some vegetables thrive in a lower-temperature growing environment.

And arugula deserves a special mention as it combines lots of flavor and attitude with minimum effort.

I invite you to read the horseradish, garlic, garlic greens, and ginger articles if you like the combination of low maintenance and lots of flavors.

Other leafy greens may also produce a good yield without too much fuss. You could grow lettuce, swiss chard, kale, or corn salad. But compared to arugula, they are all fillers.

Arugula is unique in that it delivers a unique flavor profile. 

When to grow arugula

You will learn that you can grow arugula from about April to August if you read the back of most seed packets.

I disagree. 

Arugula shines in a colder growing environment and is, in fact, more challenging to care for in the summertime.

Come summertime, the plant will mature too quickly and bolt, and generally not deliver the taste we want. Bitter arugula harvested from bolted plants is not a pleasant experience.

But arugula does respond well to a cooler growing environment. And this is good news as it makes it the ideal vegetable for early spring, late fall, and even mild winters.

Do not grow arugula in late spring or the summertime. Instead, focus your energy on the heat lovers like tomatoes, peppers, eggplant, squash, and herbs like basil.

You can start your seeds indoors, but it is easier to plant them directly in your garden. 

Arugula will grow in temperatures as low as 5 degrees Celsius (41 degrees Fahrenheit) and even survive a light frost.

Here in zone 7, we regularly start seeds as late as November in the fall and as early as February in the spring.

How to care for arugula plants outdoors

Plant your seeds in fertile well-draining soil, and make sure you water the plants. 

Slugs and snails may take a bite out of your arugula leaves
Telltale signs of slugs or snails having a snack

I can summarize my plant care routine for arugula in two steps.

  1.  Inspect your plants during different times of the day. Some lingering snails or slugs may attack your plants during early fall.
  2. Mulch around your plants if leaves get heavy and rest on the ground. 

Sometimes gardening can be simple.

Arugula is ideal for succession planting

Succession planting is when we plant our seeds in intervals to ensure that we have plants ready for harvest at all times.

Plant 5-10 seeds every 7-10 days to always have fresh arugula to harvest. 

And arugula is a perfect vegetable for succession planting as it needs harvesting no later than when it reaches maturity. And it is better to harvest early than too late. 

Leave the plant to grow for too long; it will bolt to seed and develop an unpleasant, bitter taste.

How late can you plant arugula outdoors?

The answer will, of course, depend on where you live and your growing zoneā€”but generally speaking, it is later than you think.

Arugula may be fast-growing, but it does need about 30 days to grow, develop, and mature. 

Conventional gardening wisdom will tell you to start seeds until a month before the fall frost date. 

But frankly, I disagree. 

We start seeds outdoors in our garden beds as long as the ground is frost free.

And I will give you two good reasons why.

1. Harvest arugula early

Arugula is a fast-growing leafy vegetable that packs a lot of flavors. And you do not have to wait for the plants to mature before you harvest.

Why not start harvesting when the leaves reach a useful size for cooking purposes? Again, a little goes a long way to add flavors and attitude to your salads or stir-fries.

2. Harvest this season or the next

Arugula needs about 30 days to grow, develop, and mature. 

But you can start seeds outdoors as long as the ground is frost free. And if it turns out to be too late to harvest this side of winter, you will often be welcomed by fresh arugula sprouts as the weather warms up in early spring next year.

How to start arugula from seeds

Start in fertile, moist, well-draining soil and plant seeds about 0,5 cm (1/4 inch) deep.

Seeds will germinate in 5-15 days in soil temperatures as low as 5 degrees Celsius (41 degrees Fahrenheit).

If you are planting late in the year, insulate the seeds by mulching with a thick layer of straw, hay, or pine needles.

Using temporary protective covering

Here in grow zone 7, we often have mild winters with the occasional sudden dips in temperature that can last for days but sometimes weeks.

Using a temporary cover in combination with mulching to protect your crops can help extend the harvest of cold-tolerant plants well into late fall and winter.

Place straw, hay, or pine needles around your plants and then cover them with sheets, blankets, or even row cover fabric if available.

Use stakes or pots to prop up the covering, so it does not rest on and weigh down your plants unnecessarily.

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants, and garden vegetables. For the past two years, he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.