Grow Lights for Arugula Indoors: Quick Trays
Grow lights for arugula indoors let you harvest baby leaves from shallow trays in a few weeks. University of Maryland Extension notes arugula grows acceptably well in less than ideal light plus that lights 6 to 12 inches above the foliage are typical. Sow thickly, hold trays cool plus cut leaves young.
The short answer
Hang lights 6 to 12 inches above the leaves plus run them 14 to 16 hours a day. University of Maryland Extension gives about 16 hours plus that height range. Iowa State University Extension gives 14 hours, with LED shop fixtures at 18 inches plus fluorescent T5 at 9 inches. Cut baby leaves at 21 to 40 days.
How much light does arugula need indoors?
University of Maryland Extension notes light should run about 16 hours each day plus that lettuce, arugula, mustards plus Asian greens grow acceptably well in less than ideal light. Iowa State University Extension advises 14 hours a day for indoor plants under grow lights.
| Fixture | Height above leaves | Hours per day |
|---|---|---|
| Grow light | Per package directions | 14 |
| LED shop light | 18 inches | 14 |
| Fluorescent T5 | 9 inches | 14 |
| Typical greens setup | 6 to 12 inches | About 16 |
Source: Iowa State University Extension plus University of Maryland Extension.
How close should lights hang over trays?
It hinges on fixture intensity. University of Maryland Extension notes 6 to 12 inches above the foliage is typical. Iowa State University Extension places a full spectrum LED shop fixture 18 inches above the plants plus a high output T5 fixture 9 inches above.
When is indoor arugula ready to cut?
University of Maryland Extension lists baby greens at 4 to 6 inches tall plus 21 to 40 days after sowing. NC State Extension notes arugula matures within 40 to 50 days plus that young leaves taste milder, since older leaves turn bitter.
How to: step by step
- Fill a shallow tray with damp potting mix.
- Sow arugula seed densely plus cover lightly.
- Hang lights 6 to 12 inches above the tray, or per the fixture.
- Run lights 14 to 16 hours a day on a timer.
- Raise lights as seedlings grow.
- Cut baby leaves at 4 to 6 inches tall.
Troubleshooting
Stems stretch plus flop: lights too far away. Lower them.
Leaves taste bitter: plants too old or warm. Cut younger plus cool the room.
Uneven growth: light not centered. Turn the tray.
For related reading see grow lights for cannabis, led light distance cannabis plus grow light timers. Kind Seed Co also stocks seeds for indoor growers.
Sources
- How to set up supplemental lights for indoor plants, Iowa State University Extension
- Arugula, UF IFAS Gardening Solutions
- Eruca vesicaria (arugula), NC State Extension Gardener Plant Toolbox
- Growing microgreens and baby greens indoors, University of Maryland Extension
FAQ
Can arugula grow on a windowsill?
It can in a bright window, but University of Maryland Extension notes light from a sunny window may suffice only in some cases, plus greens generally grow better under grow lights. Iowa State University Extension notes many indoor plants benefit from supplemental light, mainly in winter.
Does arugula regrow after cutting?
Baby leaf arugula can be picked as individual leaves. UF/IFAS notes leaves can be cut from the plant as needed. Microgreens are different, since University of Maryland Extension notes those seedlings will not regrow after harvest. Sow a new tray every week or two for a steady supply.
What temperature suits indoor arugula?
Cool rooms suit it. UF/IFAS notes high temperatures cause arugula to flower, plus once it flowers the leaves can turn too bitter to eat. NC State Extension notes it grows in the cooler spring plus fall because it bolts in hot weather. Place trays away from heaters.
Can I grow arugula as microgreens?
Yes. University of Maryland Extension lists arugula in the cabbage plus mustard family, which germinates plus grows faster than the beet family. It notes microgreens are 2 to 3 inches tall at 7 to 21 days after sowing plus are harvested at the true leaf stage under grow lights.
How long should grow lights run for arugula?
University of Maryland Extension suggests about 16 hours each day for greens under lights. Iowa State University Extension suggests 14 hours a day. Use a timer so the schedule stays regular, plus give plants a dark period each night so the cycle mirrors a long spring day.
