Grow Light for Dianthus Seedlings: Close Lamps Plus Full Sun
A grow light for dianthus seedlings gives these sun loving plants bright light indoors. NC State Extension notes that dianthus should be planted in full sun but can tolerate some shade. Hang lights close, run them 12 to 16 hours a day plus harden plants off before planting out.
The short answer
Hang fluorescent or LED lights 2 to 4 inches above dianthus seedlings for 12 to 16 hours a day, as University of Minnesota Extension advises. NC State Extension notes that dianthus prefers full sun. Harden seedlings off over two weeks before planting them in a sunny bed with well drained soil.
Why do dianthus seedlings need bright light?
Dianthus wants full sun outdoors, though it can handle some shade, per NC State Extension. Seedlings indoors need light near that level.
University of Maryland Extension notes that the natural light from a window is seldom enough for good seedling growth. Seedlings in a window usually stretch plus lean toward the light.
University of Minnesota Extension explains that spring sunlight is relatively weak compared to artificial light sources placed close to the plants.
How close should lights hang?
University of Minnesota Extension advises lights no more than 4 inches above the tops of seedlings. As close as 2 inches is ideal.
Plants need 12 to 16 hours of light daily, the same source notes. Standard fixtures with two cool white fluorescent tubes give adequate light at low cost.
University of Maryland Extension notes that full spectrum grow lights produce thicker stems than cool white tubes. Incandescent bulbs alone fail to grow good transplants.
| Setting | Guideline | Source note |
|---|---|---|
| Light height | 2 to 4 inches above seedlings | 2 inches is ideal |
| Light hours | 12 to 16 hours daily | Use a timer |
| Lamp type | Fluorescent or LED | Better than window light |
| Hardening off | Two weeks | Start in afternoon shade |
Source: University of Minnesota Extension plus University of Maryland Extension.
When should dianthus go outside?
University of Minnesota Extension advises hardening off over two weeks before planting outdoors. Plants started indoors will not have been exposed to full sun, wind or changing temperatures.
Start with a few hours outside in shade during the warmth of the afternoon, the same source advises. After two weeks, seedlings can stay outside in a sunny area.
NC State Extension notes that dianthus grows in different soil types. It prefers neutral to slightly alkaline soil but can tolerate some acidity.
How to: step by step
- Fill cells with moist seed starting mix.
- Start dianthus seed indoors under lamps.
- Hang lights 2 to 4 inches above the seedlings.
- Run lights 12 to 16 hours daily on a timer.
- Harden seedlings off over two weeks.
- Plant out in well drained soil in full sun.
Troubleshooting
Stretched stems: lights too high. Lower them to 2 to 4 inches.
Leaning seedlings: window light only. Move under lamps.
Leaf scorch after planting: no hardening off. Take two weeks.
For related reading see cannabis seedling light schedule, leggy cannabis seedlings plus hardening off cannabis seedlings. Kind Seed Co also stocks cannabis seeds.
Sources
- Dianthus (pinks), NC State Extension Gardener Plant Toolbox
- Starting seeds indoors, Penn State Extension
- Grow lights for starting seeds indoors, University of Maryland Extension
- Starting seeds indoors, UMN Extension
FAQ
Are dianthus perennial?
NC State Extension notes that dianthus are grown as annuals, biennials plus evergreen perennials depending on the type. The genus can be propagated by division, layering, seed or stem cuttings. Check the seed packet to see which life cycle a given variety follows before planning its spot.
When do dianthus bloom?
NC State Extension lists a bloom time of spring into summer for dianthus. The flowers have five flattened petals plus come in pink, purple, red, white or variegated shades. Many are fragrant plus good for cutting, and they attract butterflies plus other pollinators.
Can dianthus be grown from cuttings?
Yes. NC State Extension lists division, layering, seed plus stem cuttings as propagation methods for dianthus. Seed is the method covered here, started indoors under lamps placed 2 to 4 inches above the seedlings as University of Minnesota Extension advises.
What soil suits dianthus?
NC State Extension notes that dianthus will grow in different soil types. It prefers neutral to slightly alkaline soil but can tolerate some acidity. Pair that with a full sun spot, since the same source notes dianthus should be planted in full sun.
What lamp type suits dianthus seedlings?
University of Maryland Extension notes that fluorescent lights are the easiest way to control growing conditions for seedlings. Full spectrum grow lights produce thicker stems than cool white tubes. University of Minnesota Extension also lists LED lights as a good choice for seedlings.
