Grow Lights for Swiss Chard Indoors in Winter
Grow lights for Swiss chard indoors let you pick tender baby leaves through winter. University of Missouri Extension advises placing plant tips 6 to 12 inches from the light source plus running lights 16 to 18 hours a day when plants get no outdoor light. Sow chard in pots plus cut outer leaves young.
The short answer
Hang lights so leaf tips sit 6 to 12 inches below them plus run them 16 to 18 hours a day if the room gets no window light, as University of Missouri Extension advises. Iowa State University Extension gives 14 hours for most grow light setups. Pick outer leaves young for baby chard.
How much light does Swiss chard need?
UF/IFAS notes that like most greens, chard needs at least six hours of direct sunlight outdoors. Indoors, University of Missouri Extension notes that lack of light is the most common factor limiting plant growth in the home plus that intensity drops rapidly as distance from the tubes increases.
| Stage | Light distance | Notes |
|---|---|---|
| No window light | Tips 6 to 12 inches below the light | 16 to 18 hours a day |
| Some window light | Tips 6 to 12 inches below the light | 12 to 14 hours may be adequate |
| LED shop fixture | 18 inches from the foliage | 14 hours a day |
| Fluorescent fixture | 6 to 12 inches from the foliage | Move lights up as plants grow |
Source: University of Missouri Extension plus Iowa State University Extension.
What container suits indoor chard?
UF/IFAS notes chard works nicely in containers plus suggests a planter or grow bucket where garden soil carries root knot nematodes. UF/IFAS also notes chard is the same species as beet. UMass Extension notes beets grow well in deep, friable, well drained soil with high organic content, so use a deep pot of loose mix.
How do you harvest baby chard?
UF/IFAS advises harvesting leaves while they are young plus tender, picking the outer leaves a few at a time for a long, continuous harvest. Full size leaves are ready 40 to 60 days after seeding or at 8 to 10 inches long. University of Maryland Extension lists baby greens at 4 to 6 inches tall plus 21 to 40 days after sowing.
How to: step by step
- Load pots with damp potting mix.
- Sow chard seed plus water the mix evenly.
- Hang lights so leaf tips sit 6 to 12 inches below them.
- Run lights 16 to 18 hours a day on a timer if there is no window light.
- Space plants so none shades another.
- Snip outer leaves at baby size.
Troubleshooting
Leggy pale plants: light too far away. Drop the fixture or extend hours.
Uneven growth: plants under the tube ends. Center them, since tubes give less light at the ends.
Slow regrowth: crowded pots. Thin plants so light reaches all of them.
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
- Lighting indoor houseplants (G6515), University of Missouri Extension
- Swiss chard, UF/IFAS Gardening Solutions
- Beets plus Swiss chard, UMass Amherst
- How to set up supplemental lights for indoor plants, Iowa State University Extension
- Growing microgreens and baby greens indoors, University of Maryland Extension
FAQ
Can Swiss chard grow indoors all winter?
Yes, under lights. Iowa State University Extension notes that nearly all indoor plants benefit from supplemental light during winter. University of Missouri Extension advises 16 to 18 hours of light a day for plants getting no outdoor light. Pick outer leaves as they size up so the plants continue producing new growth.
Does chard regrow after cutting?
Yes, when you take outer leaves. UF/IFAS advises picking the outer leaves a few at a time for a long, continuous harvest, which leaves the center of the plant to grow on. It also advises harvesting leaves while they are young plus tender, which suits baby leaf growing under lights.
What is rainbow chard?
UF/IFAS explains that chard leaves can be dark green or red with midribs of white, red, green, orange or bright yellow. Mixes of several varieties are so colorful that they are sold as rainbow chard. The sources give no separate light figure for colored types, so grow them under the same setup.
How deep should chard pots be?
The sources listed here give no exact pot depth for chard. UMass Extension notes beets, the same species, do well in deep, friable, well drained soil. UF/IFAS notes chard works in containers plus grow buckets. Choose a deep pot of loose mix rather than a shallow microgreen tray for larger plants.
How long should grow lights run for chard?
University of Missouri Extension advises 16 to 18 hours a day for plants that receive no outdoor light plus 12 to 14 hours when some window light reaches them. Iowa State University Extension notes plants still need a period of darkness plus suggests no more than 16 hours a day for home setups.
