The next time you make lemonade from real lemons, or have some lemon wedges with a fish, save the seeds. You can grow beautiful lemon trees indoors, whether you live in the tropics or the snow belt.
Save the seeds from a lemon and wash with plain water. You can germinate the seeds in sterile soil in a paper cup, keeping it watered and covered with plastic to maintain moisture.
You also can germinate the seeds within paper towels. Moisten 3 paper towels and place them one on top of the other. Fold them in half, and then fold them in half again. Put the seeds in the middle and fold again several times to get maximum coverage and thickness.
Keep the paper towels moist continuously. You can put them on a plate that allows you to keep an additional amount of moisture in it. You also can cover the towels with wrap or a plastic bag.
Keep the towels out of the sunlight but in a warm spot. However, don't place them next to a radiator, or they will dry out quickly.
Transplant the seed to a paper cup filled with potting soil once you see a small root and leaves beginning to emerge. Make certain that the leaves are just below the soil.
Put the plant in the sunlight. It will take time for the plant to outgrow the cup. Meanwhile, look for a container twice that size for transplanting. Do not overwater. If you are using a plastic cup instead of paper, punch a few small holes in the bottom for drainage.
Using the plastic bag method of keeping the paper towels moist can reduce the chance of mold forming.