How to grow arugula (for continual harvest)

We grow arugula year-round in our own garden. And this flavorful leafy salad green has become one of our favorites.

Home grown arugula packs a wonderfully peppery flavor that store bought produce comes nowhere near to deliver. And this combination of lots of flavor and being relatively easy to grow makes arugula an ideal choice for home gardeners.

Here today we will focus on arugula (Eruca vesicaria subsp. sativa), an annual and the most common variety of arugula. There is however also a wild arugula variety (perennial) named Wall-rocket (Diplotaxis tenuifolia) that is more heat tolerant, slower growing and with a less intense mild flavor.

Arugula is an ideal vegetable to grow when you have limited space. Arugula packs a strong peppery flavor and you will find that a little goes a long way. And these are the types of herbs and vegetables we should grow with limited space. Other herbs and vegetables with lots of character and flavor include cilantro/coriander, dill, basil, horseradish, garlic, chives, lemongrass and shallots to mention but a few.

Arugula is a member of the mustard family (Brassicaceae) and most often grown as an annual. Arugula is also called rocket including variations such as roquette.

How to plant arugula seeds

Start planting seeds in starter pots indoors 6-8 weeks before last frost or directly outdoors (in situ) 1-2 weeks before last frost.

Arugula is a cool weather plant and will thrive in the shoulder or cool seasons of early spring and fall. Arugula will grow well in temperatures around 10-18 Celsius (50-65 Fahrenheit).

During warm weather arugula plants have a tendency to get stressed, bolt and set flowers prematurely. When the plant bolts the growth of new tender leaves will stop and the existing leaves turn bitter in taste.

Sow in moist, well drained soil with a spacing of approximately 3 cm / 1 inch between seeds. Plant seeds about 0,5 cm (1/4 inch) deep. As seedlings emerge, thin seedlings for plants to grow approximately 15 cm / 6 inches apart.

If planting in rows, space rows approximately 40 cm / 15 inches apart.

Arugula plants develop shallow root systems why it is important to keep on top of watering to keep soil at a consistent moisture for your plants to grow and thrive. Bottom watering the pots is another technique to help ensure that the soil absorbs enough moisture.

Arugula seeds have a high germination rate and results of 80% or more are not unusual. Germination starts between 5 – 15 days to complete.

Where should I plant arugula seedlings?

We have arugula growing in raised garden beds, pots, containers and ebb and flow hydroponic grow systems. Here are 4 tried and tested ways of how to grow arugula at home – indoors as well as outdoors.

1. How to grow arugula in your vegetable garden

Plant slow growing crops in-between rows of arugula
Plant other Brassicaceae family crops such as kale with your arugula

Avoid growing arugula in direct sunlight. Arugula is a cool season plant and prefers half shade to full sun exposure. Make sure to choose a spot in your vegetable garden that is at least in partial shade.

Arugula is a fast growing plant and is ideal to plant in-between rows of slower growing plants in the Brassicaceae family like broccoli and Brussels sprouts.

This is another reason why we love growing arugula. Arugula does not need direct sun to grow like many other plants including tomatoes, chillies, basil, Padron peppers, etc..

2. How to grow arugula in pots and containers

You can of course also continue to grow arugula in pots or containers to be placed indoors or outside. As the arugula roots grow shallow, the pot does not have to be deep. But do keep in mind that pots need a certain depth and volume of soil to effectively retain moisture and not dry out too quickly.

If you decide to grow arugula in pots (or containers), make sure they have adequate drainage holes.

3. How to grow arugula in raised garden beds

You can also plant arugula in raised beds in your garden. It is important to maintain a good and even level of moisture for arugula to grow and thrive.

Remember to water more often as raised garden beds have a tendency to dry out more quickly than a ground level vegetable garden.

4. How to grow arugula hydroponically

Arugula in ebb and flow hydroponic grow bed
Arugula grows well in hydroponic grow beds

Arugula grows well in hydroponic systems including Ebb and Flow systems and Deep Water Culture (DWC) systems.

We have had success pre-germinating arugula in rockwool cubes as well as directly in DWC net pots using LECA as a medium.

Read our beginners guide to hydroponics to learn how to grow arugula and other herbs and vegetables using water as a medium in the article DIY Hydroponics for beginners.

How to care for arugula plants

Arugula develops a shallow root system and you need to ensure that you keep the soil moist.

Avoid getting water on the leaves when watering as wet leaves will increase the risk of attracting pests and diseases.

Instead water at the base of the plant or, when possible, bottom water your pots and containers.

Use garden fabric when planting arugula

Overcrowded seedlings needs to be thinned out
Densely planted seedlings

You should use protective garden fabric from day 1 when you grow arugula outdoors.

Cover your crops with garden fabric (or row covers) to protect against the sun and heat but also pests and insects that are attracted to cabbage type plants. Simply drape the cover over your plants or use a simple wood or plastic tube structure to support the netting.

The netting looks a lot like tulle and material can be bought at garden centers or really at any fabric store to save money. The cover will protect against sun and insects as well as wind, heat, dry outs and cold on frosty mornings early in the year.

Properly covered with garden fabric our plants have even survived freezing temperatures for short periods of time.

Water and nutrition help arugula grow

Arugula needs nutrition and frequent watering to grow and deliver a good harvest. There are slow growing varieties of arugula but the most common and popular varieties grow fast.

You want to stimulate fast growth as it helps develop the characteristic peppery flavor and a crisp texture.

Mulching with fresh grass clippings or other organic compost materials is a good alternative as it adds nutrition while helping to retain soil moisture.

If you succession grow you must fertilize in-between each batch you plant or you will end up with poor growth and tired looking yellow leaves.

How and when to harvest arugula

Arugula is a popular leafy vegetable that should be harvested continually. Arugula takes 25-30 days to develop and leaves are harvested from outside-in.

You should harvest the outer leaves from outside-in to protect the newer younger leaves as they emerge.

Another method is to simply grab the plant and cut a bunch of leaves using a sharp knife or a pair of scissors.

Harvesting arugula for cut and regrow

Harvesting arugula leaves for cut and regrow will work, but you will experience a diminishing rate of return with less and less leaves to harvest. As we succession sow arugula we rarely harvest with re-growth in mind.

The first stage of harvesting will actually take place when you thin out the weaker seedlings as they develop. These delicate leaves are delicacies and are sold as baby arugula in grocery stores.

How to grow arugula for continual harvest

You can grow arugula indoors year-round in soil and hydroponic grow systems.

Plant arugula seeds outdoors from January – June and then again from August – December. This effectively means that the growing season extends for the entire year with the exception of the month of July when the weather is too hot.

Seeds will germinate at temperatures as low as 5 Celsius (41 F) and the plant will even survive mild frosts if protected.

You can plant arugula every 2-3 weeks outdoors throughout the year as long as you use protective covering during the colder periods of the year.

How to harvest arugula seed pods

To harvest your own seeds simply allow the plant to flower and collect the seed pods as they develop.

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.