Though easy to care for, knowing a few things before taking on the responsibility of growing your own will help ensure that you keep your tree healthy, providing you with delicious harvests for years to come.
Light
It is not hard to assume that grapefruit trees thrive in full sun. Getting your tree to thrive and produce the most abundant harvest will take placing it in a location where it gets six hours of sun a day. Full sun means completely unshaded, so removed from the shade of other trees as well, which in the case of the grapefruit tree is easy; the grapefruit is self-pollinating, so only one tree is needed to produce fruit. If two or more trees are planted, plan to space them far enough apart that they do not shade each other throughout the day, this also limits the amount of pruning you will need to do later.
Soil
Providing good soil with a lot of nutrients for your grapefruit tree is essential for fruit development. Make sure you plant your tree in a place with rich soil loaded with organics, or you will need to plan to amend the area before planting to get it just right. Getting the right soil can be accomplished by adding some high-quality compost to the existing soil to make the soil good and rich to fuel growth, contribute to health, and boost fruit production. It is pretty easy to make your own to save some money. The soil should also be able to drain with ease. While the grapefruit tree is terrific at resisting disease, it does not do well at resisting root rot, which is caused by overly wet roots.
Water
Grapefruit trees do not require much water compared to other fruit trees. Once planted, a young tree should be deeply watered three times a week to help it establish itself. After the first year, you can reduce this to once a week unless there has been a good amount of rain, then your job has been done for you; if it has been especially dry, then you may want to increase the watering to two soaking waterings a week.
Temperature and Humidity
The only real deterrent most people encounter is when they get the urge to try their hand at growing grapefruit and realize they are not in the right climate. It might not be the tree to grow if you are not located in a tropical or sub-tropical region. Grapefruit trees grow well in tropical and subtropical climates but are slightly less cold-hardy than oranges. This makes pushing the northern zone limits iffy. Some people attempt growing a grapefruit tree in extra large pots on patios during the summer if they have warm, sunny interior locations indoors that maintain a temperature above 70°F. This growing method may not successfully produce fruit or have an abundant yield. To guarantee the best shot at producing fruit and keeping your tree healthy, only grow it in a region where it will thrive; the USDA recommends hardiness zones 9 to 11.
Fertilizer
All citrus trees are notoriously heavy feeders and will demand a lot of supplemental nutrition. The second year after your grapefruit tree has been in the ground, you will begin one of the most important steps in its care if you want to produce a bountiful harvest. At this point in the tree’s life, you will begin the chore of fertilizing the tree three times a year. Your first application is in January, the second in May, and the third in June. The product you will be aiming to use is one high in nitrogen, which is the first number in those three numbers seen on fertilizers, an ammonium sulfate (21-0-0), or pre-mixed citrus fertilizer is perfectly fine unless the tree is planted directly onto a lawn. Lawns are nitrogen sponges, so you will need to compensate and look to add extra nitrogen, in which case urea (46-0-0) can be applied by watering into the soil about one to two feet outside the drip line.
Types of Grapefruit Trees
Grapefruit, Citrus x paradise is a hybrid of two distinct species and the accidental outcome of the interbreeding of the pomelo, Citrus maxima, and orange, Citrus × sinensis. The naturally occurring hybrid has allowed breeders to experiment with many varieties exploring taste, color, hardiness, size, and form. While some varieties are bred through normal means or simple luck, modern commercial varieties are often accomplished through irradiation. Many of these cultivars are patented and often unavailable to the nursery trade, having their sole use in canning or juice production. Some varieties you will surely recognize, and others are varieties that have been used as stepping stones to achieve a final form of fruit we are now familiar.
Citrus x paradise ‘Ruby Red’: Undoubtedly the most famous grapefruit cultivar on the market. It is a patented variety that initially appeared as a mutation of a pink variety. Citrus x paradise ‘Rio Red’: This variety is achieved by irradiation that produces very dark fruit and juicer fruit.Citrus x paradise ‘Thompson’ A variety of pink grapefruit available to the public. This is the original plant from which ‘Ruby Red’ was bred.Citrus x paradise ‘Duncan’ This is the oldest white grapefruit cultivar grown, bred off a seedling in 1830. It is known to be very seedy but extremely flavorful and juicy.
Pruning Grapefruit Trees
The type of pruning you will do on your grapefruit tree will depend on the size, location, and the number of trees you have. If you have a singular grapefruit tree with plenty of room and nothing cramping your tree’s style, the biggest chore you will do is maintenance pruning. This pruning is the normal chore of looking for dead and damaged branches and structural pruning, ensuring the tree’s crown grows up and out, away from the main trunk. If you have multiple trees, you will want to prune to give each room space to allow each tree to get proper sunlight and allow yourself to inspect and access the trees readily. Your main goals in pruning a grapefruit tree are not for aesthetics. You are trying to improve air circulation, rejuvenate the tree, reduce shade, improve fruit quality, and make harvesting and further care easier.
Propagation
Propagating a grapefruit tree can be done by cuttings, but a few things make it a wiser choice to go the way of buying a tree from a well-respected nursery. First, most citrus that produces fruit sold in nurseries is grafted onto rootstock much harder than its original roots; most often, it is Citrus trifoliata or hardy orange. This species of orange is more disease-resistant, cold-hardier, and less susceptible to pests. The second concern is legality, many grapefruit varieties are patented. Propagating them is illegal, and it is just not worth the risk.
Common Pests and Plant Diseases
While most of the diseases and pests you might encounter in your grapefruit-growing adventures are relatively harmless, two big issues need to be worried about that. Citrus green and Asian citrus psyllid are linked and should be considered to preserve your tree. Citrus greening is a devastating bacterial disease that spreads from citrus tree to tree or is carried by the invasive insect, the Asian citrus psyllid. The symptoms will be shrinking fruit size, bitter taste, and yellowing leaves. Unfortunately, there is no way to manage the disease; removing the infected tree is the only recourse. The best prevention is to look for the Asian citrus psyllid, a tiny little brown flying insect.
