Grapefruit trees (Citrus X paradisi) are evergreen, fruit-producing trees that can grow from 20 to 50 feet tall, depending on the variety. The grapefruit is actually a result of a cross between an orange tree (Citrus sinensis) and a pummelo (Citrus maxima).
Besides their fruit-producing capabilities, some gardeners grow grapefruit trees as ornamentals and for their sweetly-scented flowers, which appear in early spring. Growing grapefruit trees from seed is easy.
Remove the grapefruit seeds from the fleshy pulp of the grapefruit. Put the grapefruit seeds into a wire basket or a kitchen strainer. Pour water into your kitchen or bathroom sink. Drop in no more than 1 teaspoon of bleach into the water. Immerse the wire basket or strainer into the bleach and water solution. Do not allow the strainer or wire basket to sit in the bleach and water solution. A quick immersion is all that is needed. Then, rinse off the grapefruit seeds with warm water for approximately 1 minute.
Spread the grapefruit seeds onto paper towels and let them dry for about 1 to 2 hours.
Fill 1-gallon plastic pots with sterilized potting mix. If you want to create your own potting mix, measure out and mix together equal values of fine sand, vermiculite or perlite and peat moss. Then, water each of the pots to saturate the potting mix. Use a block of wood, or the base of a smaller pot to tack the soil down firmly in each of the 1-gallon pots.
Poke one to two 1/2-inch deep holes in the middle of each 1-gallon pot. Plant one grapefruit seed into each hole. Sprinkle no more than 1/2 inch of either the purchased potting mix, or the mix you made yourself over each the of the holes. Pour water into the 1-gallon pots using a gentle stream of water and make sure you've watered well enough for the water to reach down to the grapefruit seeds.
Put each one of the 1-gallon pots where they can receive a good source of warmth. Ideally, any location where the temperature will remain fairly consistently around 65 to 70 degrees F. To ensure ample moisture and to help keep the soil in the pots warm, cover each of the 1-gallon pots with a layer of plastic wrap.
Remove the plastic wrap from the 1-gallon pots once you seed grapefruit seedlings emerging from the soil. Then, transfer each of the pots to where there is a good, steady source of 8 to 10 hours of light daily. Keep the grapefruit seedlings indoors, until they are well established. This can take anywhere from 1 to 2 years.