Position – Plant your grapefruit in full sun, where they will get 8 to 12 hours of sunlight every day. If you live in a region with mild winter frost (-1°C to -2°C), then opt to grow lemons, navel oranges, naartjie varieties (satsumas), clementines and mandarin hybrids, limes and kumquats.
Size – Most grapefruit trees reach a mature height of between 5 and 6 metres, but some have been to grow as tall as 13 to 15 metres.
Soil Type – Grapefruit trees require slightly acidic soil with a pH of between 5.5 and 6.5. Ensure that you have good drainage.
If you plan to grow your grapefruit tree in a 50 x 50 x 50 centimetre pot, use a whole bag of our volcanic rock dust with a mixture of compost and potting soil. Place stones on the bottom of your pot for good drainage. The plants will thrive in a container if they receive enough sunlight and are protected from freezing winter weather.
Volcanic rock dust re-mineralises your soil for better growth and fruit production.
If you’re planting your grapefruit tree in the ground, dig a hole at least 50 centimetres wide and 50 centimetres deep. If the soil is loamy (not clay), mix it with a bag of our volcanic rock dust.
Watering – Water this tree regularly to keep the soil moist at all times, particularly when they are flowering and setting fruit. For the rest of the year, ensure that the soil never dries out completely.
Mulch – Mulch around the tree with pine needles or pine bark (available at Just Berry Plants). Mulch will maintain soil moisture and keep the soil slightly acidic. It helps to keep pests away as well. Do not let the mulch touch the plant stem, as it may cause rot and infection.
Fertiliser – Grapefruit trees need a high nitrogen fertiliser added through the winter to spring. You will find this at hardware stores and most nurseries.
Pests – Pests like mealybugs, spider mites, aphids and scales occasionally attack grapefruit trees. A natural organic pesticide to use is 1 teaspoon of Neem oil in 1 litre of water and a little dishwashing liquid. Spray your plant with this mixture regularly every 2 weeks to prevent any problems. Throw the remaining solution onto the soil around the plant (it is good for the soil). Do not keep the mixture for longer than 8 hours.
Pruning – A good time to prune your citrus tree is once it has stopped fruiting. Remove branches in the middle of the tree to thin it out as this will aid in pest and disease control. Prune the tree to your desired height to enable easier harvest. During the year, cut away branches that cross over one another and remove any tangled leaves, twigs and branches to enable vertical growth.
Harvesting – Grapefruits are ready to be picked when at least half of the skin has changed colour.