Most seeds will not germinate without sunlight and will perform best with 12 to 16 hours each day. Indoors, place seed containers in a sunny, south-facing window and give the container a quarter turn each day to prevent the seedlings from overreaching toward the light and developing weak, elongated stems.
Not all seeds have the same light requirements. 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).
Some plants germinate well in darkness, some prefer continuous light, and others have no preference either way. Apparently it was custom in Ancient Egypt, before finally sealing the tomb, to leave a little pile of moistened corn near the sarcophagus.
Days 1 – 3: Place your seedlings outdoors in a shady spot that will only get 3-5 hours of direct sunlight throughout the day. Days 4 – 5: Place your seedlings in a slightly sunnier spot that will get about 5-6 hours of direct sunlight. Days 6 – 7: Place your seedlings in a full sun spot (6+ hours of direct sunlight).
Most seeds can germinate in darkness or light (one exception is lettuce, which needs light) but once the seeds have sprouted, keep the lights on about 12-16 hours per day.
Most of the seeds germinate best in dark environments. The presence of light tends to inhibit their growth. The light decomposes carbonic acid gas and expels oxygen which leads the seed to harden. These gases are key factors that promote germination.
All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also. Some germinate better in full light while others require darkness to germinate.
While many houseplants can thrive away from any direct light source, seedlings need a good windowsill or some grow lights to provide the energy they need to grow! Moreover, they are sensitive to direct sun, more so than many adult plants are, so picking the right kind of bright spot is crucial.
It is true that seedlings need lots of bright light to grow healthy and strong—but they also need a period of darkness in order to thrive.
Seeds need to be moderately moist to sprout. Seed germination is highly dependent on watering. Too dry and they won't get the message to sprout, too wet and they will rot in the dirt.
There isn't much to it - sprouts can grow just about anywhere - as long as they can breathe, but don't have so much air movement that they dry out between Rinses. We set our sprouter on our kitchen counter. We don't mind the diffuse sunlight or the 150 watts of incandescent light. Light just does not matter much.
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.
Most seeds will not germinate without sunlight and will perform best with 12 to 16 hours each day. Indoors, place seed containers in a sunny, south-facing window and give the container a quarter turn each day to prevent the seedlings from overreaching toward the light and developing weak, elongated stems.
Seedlings should be watered once a day or every other day, depending on how much sun and heat they get. Remember that seedling roots are fairly close to the surface and they're growing in a small amount of media, so they don't need a deep soak the way larger plants do.
Some seeds like Allium 'Purple Sensation' and Eryngium giganteum need a long period of cold-moist stratification with alternating temperatures. These are the most difficult seeds to germinate.
One of the most popular ways to germinate seeds is the paper towel method.
Some are quick to germinate, taking 1-2 weeks at most, such as chillies, beans, sunflowers and pumpkins. Some seeds take more like 2-4 weeks, such as mango and parsley. Others, depending on how warm/cold it is, take closer to 2 months, for example avocado.
Most seeds need to take up water to germinate; this is known as imbibition GLOSSARY imbibitionthe taking up of liquid, causing swelling. . Water: hydrates enzymes in the seed, activating them. As a result the seed begins to release energy from its food store for growth.
Hydrogen peroxide (H2O2) is quite popular in horticulture. It has an extra oxygen atom than water (H2O). When its molecule breaks down, this extra oxygen separates from the water, acting as a supplement to plants. It also helps in germinating seeds successfully by making them absorb more oxygen.
For seeds to germinate, you need to keep the growing soil damp but not too wet. Learning how to water seedlings is pivotal for success. Many seed starters cover the container to keep soil moist until seeds germinate. Once seeds sprout, do not miss a watering.
Germination depends on several environmental factors, e.g., water, oxygen, temperature, and often light and nitrate as well. Of these, water is the most essential factor.
The germination process begins when water is absorbed (imbibed) by the seed. This initiates several biochemical events necessary for seedling development. For example, enzymes secreted from the aleurone layer, break down starch in the endosperm converting it to simple sugars which nourish the embryo.
There are four environmental factors that affect seed germination: Water, Light, Oxygen, and Heat.