When I first started gardening I had no idea just how perennial arugula really was! Most seed packages suggest arugula is grown as an annual but here on the west coast arugula is a drought tolerant, grow anywhere, tenacious self sowing, verging on invasive, perennial edible. If only I had known.
Like keeping order in the garden? Have time on your hands to successive sow? Grow arugula as an annual. You can start very early in the spring, with transplants or direct seeding, when plants reach 4” in diameter, they should have produced a hand full of 2” long gently grooved leaves, at this point take the whole plant out by the root before it shoots up a flower and dumps seeds all over the place. The first year I grew arugula, I did grow it as an annual.
I don’t have time to constantly resow arugula every couple weeks for a single fist full of greens. Sure it would be nice to not have to constantly pull baby arugulas out of every corner of the garden because I yet again, let a mother arugula go to seed. But aside from that I much prefer arugula as a perennial it produces much more, much sooner much faster. While annual arugulas are just barley ready to be picked, my 3 established perennial arugulas yield about ½ a salad spinner of leaves every day spring through fall. To get the long deeply lobbed leaves we are all familiar with seeing in stores, you do need to let arugula grow for at least one full season.
To grow perennial arugula start the same way you would in the annual scenario but when harvesting keep the roots intact, just pluck the leaves. If you are looking to have a garden or yard full of arugula allow it to flower and go to seed, you can snip the flowers and toss them in salads but arugula will still shoot up stems full of seed pods so watch out. If you have a small garden I would highly recommend clipping off the seed pods before you are in a hostile arugula take over situation. After a year or so The arugula plants will grow into a big two foot by tow foot loose leaf bush, that literally looks like a heap of salad greens. Maintenance for perennial arugula is minimal. Last year I had so much self sown arugula I didn’t bother fertilizing, heck I didn’t even bother watering, in hopes I might just loose a few of the smaller plants. The only thing I did do was clean up the dead stems once the plants died back in the winter, I didn’t mulch or cloche. My bigger arugula plants are resilient to the heat of summer but the flavor of the leaves does become quite spicy. My favorite time of year for arugula is right now in the prime of spring the leaves are tender and mildly peppery.