Plastic bag germinator

Plastic bag seed germinator

Difficulty:

Time: 5 minutes

Adult supervision: no

Dangers: minimal

Materials

Zip lock plastic bag (sandwich size approx. 18 x 17 cm)

Paper towel

Seeds (bigger seeds are better to see the germination process e.g. pumpkin, broad beans, zucchini)

Water

Method

Fold the paper towel into quarters.
Dampen the paper towel with water.
Place damp paper towel inside the plastic bag.
Put one or two seeds on the paper towel.
Label the bag with the date and type of seed.
Place the plastic bag in a warm place. If you're allowed, you can even tape it to a sunny window.
Now you have to wait a few days until your seed germinates.
When the seedling gets bigger, you could transfer it to a proper terrarium, plant it in a pot or plant it in the garden (if it's warm enough for it to survive).

The Science

Germination

Seeds are dormant. When the conditions are right, they will germinate.

Moisture is needed to soften the hard, outer protective layer of the seed called the seed coat or testa.
Temperature: some seeds require a certain temperature to germinate. Some seedlings cannot survive cooler temperatures or frosts so its no point germinating in winter.
Oxygen: if the seed is buried too deep or the soil is too wet, there may not be enough oxygen available for the germinating seed to carry out metabolism.
Light or dark: some seeds require light others require darkness.

When a seed germinates, the radicle emerges first. This part becomes the root of the plant. Next, the plumule emerges. This becomes the stem and leaves of the plant. The cotyledon is the embryonic leaf forms.

Monocotyledons vs Dicotyledons

Monocotyledons (or monocots) are flowering plants with an embryo that bears a single cotyledon (seed leaf). Monocotyledons constitute the smaller of the two great divisions of flowering plants, and typically have elongated stalkless leaves with parallel veins (e.g. grasses, lilies, palms).

Dicotyledons (or dicots) are flowering plants with an embryo that bears two cotyledons (seed leaves). Dicotyledons constitute the larger of the two great divisions of flowering plants, and typically have broad stalked leaves with net-like veins (e.g. daisies, hawthorns, oaks).

Here are photos of my bean seed germinating:

Day one.

Day 5: radicle (root) has emerged.

Day 8: root system is forming and you can see the green plumule

Day 12: root system is growing.