------------------------- Before they can grow into new plants, seeds need to leave the seed pod. If all the seeds a plant produced landed just underneath the parent plant, they would be too crowded, and the established large plant might not leave them enough light or water for them all to develop properly. When you plant seeds too thickly in a pot, you can see that they grow tall and leggy, and each plant is weak and spindly. The various methods of seed dispersal are designed to ensure that as many seeds as possible have a good chance of growing up to produce seeds of their own.
Sometimes, the pod or fruit containing the seeds is carried away from the parent plant; sometimes, individual seeds are spread to a new location. The size and shape of the seedpod or the seeds influences how they are dispersed. The main methods plants use to disperse their seeds to places with better growing conditions than directly under the parent plant include gravity, animals, force, wind and water. Often, a plant will spread its seeds by a combination of these methods. For instance, a fruit falling to the ground by gravity might then be carried away by animals, or a seed blown by the wind might land in water and be transported somewhere else before germinating.
On some plants native to Australia and South Africa, the seedpods may need the heat of the natural bush fires occurring in these areas to open and release their seeds, which are then dispersed by other means.
Monocotyledons (monocots) and dicotyledons (dicots) make up the two large groups of flowering plants, differentiated by their seed structures. Monocot seeds contain one cotyledon, or embryonic leaf. When these seeds germinate, the cotyledon remains below ground, absorbing nutrients from the endosperm, the starchy food supply in the seed. The coytledon transports these nutrients to the developing seedling. Dicot seeds contain two coytledons, which absorb and store the nutrients from the endosperm before the seed germinates. The cotyledons, thick with stored nutrients, emerge above ground during germination, and then transport the stored nutrients to the developing seedling. For a brief time, the cotyledons also serve as the first photosynthesizing leaves, but they wither and die when the true leaves emerge.
2. Seed Germination
According to Katina Mooneyham, starting seeds and plants indoors is a good idea, especially for the kids' garden. It starts the season and the kids can get a good grasp on germination and plant needs. Seed experimenting can also help germinate a kid's interest in gardening.
Paper towel experiments
There are many experiments to try with seeds and paper towels. Maybe you could see whether those extra absorbent towels hinder, help or don't affect the seed's sprouting abilities. You can observe and make a mental note about which, if any, paper towels help seeds grow faster or slower. You could make it a science project. If you use it as a science project, you will need to make notes in a journal. You should keep the amount of water and light the same for each paper towel unless you're experimenting on other factors.
Seed growth rate
What affects the seed growth rate? Make a list of the things a plant needs, then try changing one of those factors. The list should include sunlight, water, food and air. Does changing any of these factors affect how fast the seed germinates?
Growing without soil
Believe it or not, seeds and plants can be grown in just water. It's a plant science known as hydroponics and can be very effective (and clean) for growing plants. You can do experiments with different plants and compare growth in water to traditional growth in soil. Start the seeds the traditional way and see if you can get some to start in just plain water.
Does soil matter?
Does the type of soil matter? Test this by conducting an experiment. Get several different types of soil. For example, get top soil, potting soil and a germinating mix. Take three seeds of the same kind. Place equal amounts of each type of soil in three-inch pots. Then plant one seed in each pot. Take notes. Does one seed grow faster than the others? Do any of the seeds grow fast and then just stop growing? Let the experiment run on for a few weeks.
There are so many experiments that kids can do to have fun with seeds. Start the gardening season with knowledge that will help you succeed in this year's gardens.
