Grow Light for Kale Indoors for Baby Leaf Harvests
A grow light for kale indoors is a simple way to grow baby leaf kale, since kale is a cool season green that tolerates partial shade. NC State Extension notes baby greens can be picked 20 to 30 days after seeding. Sow thickly in a tray, hang lights close above the seedlings plus cut young leaves often.
The short answer
Kale suits indoor lights because it tolerates partial shade of 4 to 6 hours of direct light a day, per University of Maryland Extension. Space seed 2 to 4 inches apart for baby leaf plants. NC State Extension notes baby greens are ready 20 to 30 days after seeding. Hold the room below 75F.
Why does kale suit indoor growing?
NC State Extension notes kale is a cool season leafy green, plus Utah State University Extension notes it grows well when temperatures do not exceed 75F. University of Maryland Extension notes kale tolerates partial shade of 4 to 6 hours of direct light a day. A shelf under shop lights suits that lower light need.
| Factor | Guideline | Source |
|---|---|---|
| Direct light tolerated | 4 to 6 hours | University of Maryland Extension |
| Baby leaf spacing | 2 to 4 inches | University of Maryland Extension |
| Seed depth | 1/4 to 1/2 inch | Utah State University Extension |
| Baby greens | 20 to 30 days | NC State Extension |
| Mature leaves | 50 to 75 days | NC State Extension |
| Upper temperature | 75F | Utah State University Extension |
Source: University of Maryland Extension, NC State Extension plus Utah State University Extension.
How close should shop lights hang over kale?
Hang shop lights close above the seedlings plus raise them as the leaves grow. Seedlings stretching toward the lamp show it hangs too high. University of Minnesota Extension notes tender flavorful kale comes from fast growth without heat or moisture stress, so steady light on a timer plus a cool room suit it.
When is baby kale ready to pick?
NC State Extension notes baby greens can be picked 20 to 30 days after seeding, while mature leaves take 50 to 75 days. University of Maryland Extension notes closer spacing of 2 to 4 inches gives small plants that can be harvested repeatedly. Cut young leaves above the growing point so new leaves form.
How to: step by step
- Fill a shallow tray or pot with moist potting mix.
- Sow kale seed 1/4 to 1/2 inch deep plus close together for baby leaves.
- Hang shop lights close above the seedlings.
- Run the room cool, not warm.
- Water from below when the mix starts to dry.
- Cut young leaves above the growing point plus let them regrow.
Troubleshooting
Leggy seedlings: light too high. Drop it.
Bitter leaves: heat or water stress. Cool the room plus water evenly.
Seedlings collapse at the soil line: wet still air. Add airflow plus water less.
For more on lighting see grow lights for cannabis, optimal lighting for growing indoors, grow light timers plus cannabis seeds. Kind Seed Co also stocks seeds for indoor growers.
Sources
- Kale, NC State Extension
- How to grow kale in your garden, Utah State University Extension
- Growing leafy greens in a home garden, University of Maryland Extension
- Growing collards and kale in home gardens, University of Minnesota Extension
FAQ
Is baby kale the same plant as full size kale?
Yes. University of Maryland Extension notes closer spacing gives smaller baby leaf plants while wider spacing gives larger plants. University of Minnesota Extension advises spacing plants as close as four inches apart for baby leaves only. The seed is the same, so any variety can be cut young under a grow light.
How many times can baby kale be cut?
University of Maryland Extension notes closely spaced plants 2 to 4 inches apart can be harvested repeatedly. The count depends on growth, so cut leaves above the growing point plus watch how fast they regrow. When new leaves slow down or turn bitter, sow a fresh tray to follow on.
Does kale need a special grow light?
Not usually. University of Maryland Extension notes kale tolerates partial shade with 4 to 6 hours of direct light a day, well below what fruiting crops need. That makes simple shop lights hung close above a tray a practical choice. Run them on a timer so plants get the same day length daily.
Can kale grow on a windowsill?
It can, since University of Maryland Extension notes kale tolerates partial shade of 4 to 6 hours of direct light. A bright window may give that much, though winter days are short. Utah State University Extension notes kale prefers a sunny location, so add a grow light when growth looks slow or leggy.
What temperature suits indoor kale?
Cool. Utah State University Extension notes kale grows well when temperatures do not exceed 75F plus young plants handle cold down to 25F. University of Minnesota Extension notes overheated plants produce pungent or bitter flavors. Set the tray in a cool room away from heaters plus warm windows.
