Do seeds germinate better in light or dark?
Most seeds germinate best when they’re placed in the dark. The presence of light, which is crucial to seedling development, may actually stunt the process of germination.
How does light intensity affect seed germination?
Seed size did not affect germination percentage, but seeds sown under high light intensity had a lower germination percentage than seeds sown under low light intensity and darkness. Thus, seed germinability of C. oblongifolia was higher in darkness while seedlings exhibited greater development under light.
Why does light not affect germination?
The explanation of how light affects some seeds and causes them to be in a state of readiness for germination and yet prevents other seeds if necessary from germinating is highly complex. In such a case with a seed which required darkness, uncovered seed, which is exposed to light will not germinate.
Do seeds germinate better in the light?
Most seeds germinate best under dark conditions and might even be inhibited by light (e.g., Phacelia and Allium spp.). However, some species (e.g., Begonia, Primula, Coleus) need light to germinate (Miles and Brown 2007). Don’t confuse seed light requirements with what seedlings need. All seedlings require sunlight.
Should seedlings get 24 hours of light?
In general, seedlings should receive roughly 14 to 16 hours of light a day when situated in a south-facing window. Many people make the mistake of leaving their seedlings under fluorescent lighting 24 hours a day. This does not make them grow faster, and can actually hinder the success of your seedlings.
Why do seeds grow faster in the dark?
The light slows stem elongation through hormones that are sent down the stem from the tip of the stem. In the darkness, the hormones do not slow stem elongation. The seeds in the dark-grown condition rely upon the stored chemical energy within their cells (lipids, proteins, carbohydrates) to power their growth.
Can seeds get too much light?
One common mistake in starting seeds is supplying the right amount of light. Yes, it is true that your seedlings need lots of bright light to grow healthy and strong—but they also need a period of darkness in order to thrive. This does not make them grow faster, and can actually hinder the success of your seedlings.
How do I know if my seedlings are getting too much light?
If your plant is not getting enough light, the most common sign is the yellowing and dropping of leaves, stunted leaf growth, elongated stems, and a dull-green color. If your plant is getting too much light, then its leaves will have singed tips, burned patches, or will be falling off (yikes!).
How do you know if light is too close to seedlings?
The first signs look like thin outlines on the outside of the leaves, so if you catch this quickly you will have a chance to avoid further damage. If some of the leaves start curling up, it might also be a sign that the plant is too close to the light. Good ventilation usually also helps with this issue.
Should you start seeds in the dark?
Planting Seeds Too Deeply Some seeds need complete darkness to germinate and others require light to germinate. 1 Proper planting depth is usually provided on the seed packet. If there is no information on the packet, the rule of thumb is to plant seeds two to three times as deep as they are wide.
Can a seed grow in the dark?
Seeds will not germinate so well in light as in darkness ; because light decomposes the carbonic acid gas, expels the oxygen, and fixes the carbon; thus hardening all the parts of the seed, and preventing vegetation.
Can seedlings get too much light?
To put it bluntly, yes, too much light can eventually kill your plant. The light intensity can produces increasingly severe damage to your plant to the point where it dies. It can also dry out the plant to the point where it no longer has the water it needs for growth and photosynthesis.
How do you know if your plant is getting too much light?
Signs your plant may be getting too much light;
- Brown leaf edges or tips.
- Brown, dry patches on the leaves.
- Leaves turn pale or yellow, particularly those most exposed to the light.
- Yellowing may be noticeable in the leaf tips first.
- Leaf yellowing may not affect the leaf veins initially.