Grapefruit seedlings with undesirable fruit can still be enjoyed for their highly fragrant, waxy white flowers.
Grapefruit trees are typically propagated with bud grafting to increase their resilience and hasten fruiting. Seed-grown grapefruit trees often prove less reliable than their nursery-grown counterparts, and may include drawbacks such as:
Watch for the first grapefruit seedlings in two to three weeks. Remove the plastic after they emerge, and move the pot to a bright, sunny spot indoors near a lightly shaded south-facing window.
Grapefruit seeds go dormant if they dry out. Soak them in clean, room temperature water for 24 hours before sowing to revive them.
Repot the grapefruit seedlings in spring into a pot that is no more than 1 to 2 inches larger than the previous pot. Use soilless medium and a pot that has multiple drainage holes around the base.
Grapefruits fall into two categories: white-fleshed and red-fleshed. Common white-fleshed varieties include the ‘Duncan’ grapefruit (Citrus x paradisi ‘Duncan’), which is a seedy variety with 30 to 50 seeds in each fruit. Red-fleshed varieties include ‘Ruby’ (Citrus x paradisi ‘Ruby’), which is a common grapefruit at supermarkets. ‘Ruby’ is a seedless variety, which means it has six seeds or fewer per fruit.
Cover the seeds completely with soil to block out the light. Loosely drape a sheet of plastic wrap over the pot and move it to a warm spot where temperatures stay between 70 and 80 degrees Fahrenheit. A propagation mat works well, but the pot will stay just as warm on top of a refrigerator.
Transplant all of the sprouted seedlings into individual 3- to 4-inch pots filled with sterile soilless growing medium once they produce several sets of leaves. Be sure to plant them at the same depth as they were in their starter pots. Use pots that have drainage holes.
Soilless potting medium
Grapefruit trees sprout easily from seeds, although the seedlings lack the same fruit quality as commercially grown trees.
Water the newly planted seed until the soil is moist but not soggy. Cover the pot loosely with plastic wrap to create a greenhouse effect to keep the seed warm and encourage growth.
Transplant the seedling to larger pots, such as 6-, 8- and 12-inch containers, as it grows so the roots will have plenty of room.
A south-facing window covered with sheer curtains provides sufficient light without exposing the seedling to direct sunlight, which may burn the plant.
Press one grapefruit seed into the center of the pot. Push the seed into the soil so it is twice as deep as the seed is long. For example, if the seed is 1/4 inch long, plant the seed 1/2 inch deep.
How to Plant Grapefruit Seed
The grapefruit (Citrus paradisi) has come a long way. From its first recorded history in the West Indies during the mid 1700s to propagation in Texas’ Lower Rio Grande Valley during the early 1900s, the grapefruit has become a fruit that can stand alone or be used as an ingredient in the kitchen. Grapefruit can be grown at home from seeds and planted outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11. Although fruit production can be more limited than that of commercially grown trees, growing a grapefruit tree from seed should produce fruit.
Place the covered pot in a brightly lit, warm location with a consistent temperature of around 70 degrees Fahrenheit. Monitor the progress of the plant, adding water as necessary to keep the soil moist. Watch for the seed to sprout and leaves to form.
Under ideal conditions the grapefruit seedling may flower and produce fruit in six to seven years.
Remove the seeds from a fresh grapefruit. Wash the seeds under running water and pat them dry with a towel.
You can grow your own grapefruit tree from seed harvested from your breakfast fruit. Plant the seed and keep it warm so it germinates indoors.