Vinegar that tastes sweet. Ice cream that tastes sour. Such are the effects on your taste buds after first chewing upon a miracle fruit. The slow-growing tropical shrub from where the miracle is born, Synsepalum dulcificum, is native to tropical western Africa and appreciates a warm, moist and acidic soil. When grown in conditions free from frost, it can attain a height up to 18 feet and a width of 8 feet. Situate it in a garden bed or container that will receive partial sun to partially shaded light exposures. The plant's small red fruits have no taste on their own, but miraculously transform the tastes of foods eaten thereafter.
Determine the USDA Plant Hardiness Zone for your location. Miracle fruit can tolerate only an occasional light winter frost but should not be grown outdoors where temperatures drop below 30 degrees Fahrenheit. This equates to USDA Zones 10 and higher. Elsewhere, grow this plant in a container, overwintering it indoors as a houseplant.
Provide a soil that is moist, well-draining and highly acidic, with a pH reading of 4.0 to 5.5. Outdoors the soil should be sand-based but rich in organic matter. Container-grown plants excel in a peat-based potting medium.
Situate the shrub outdoors where it will receive between four and nine hours of direct sunlight each day, which is regarded by gardeners as a partial shade to partial sun exposure. In more arid or hot summer climates, consider providing shade to the miracle fruit during the afternoon, from 12 noon to 5 p.m. Indoors, provide it very bright light with occasional direct sunlight in all but a northern window.
Plant miracle fruit by digging a hole with a garden shovel the same depth as the container from which it grows but twice as wide. Back-fill the hole with the soil once the plant is placed in the hole, matching the top of the rootball with the top of the hole. Do not plant too deeply and do not pile excess soil atop the rootball and around the trunk. Indoors, the plant can be re-potted as needed, but always planted at the same depth in the pot with more room around the sides, as in a larger diameter container.
Water miracle fruit after planting to remove air pockets in the soil around the rootball. Water should drain from the soil surface or container drainage holes within five minutes. Keep the soil moist but never dry or soggy.
Top dress the area above the rootball of the shrub with an acid-forming mulch like pine bark or coffee grounds at a depth of 1 to 4 inches. On sandy soils, make the mulch depth 3 to 4 inches. Always keep mulch or soil top dressings like compost 2 to 3 inches away from the trunk of the plant.
Lightly fertilize the miracle fruit with a slow-release, all-purpose granular fertilizer in spring, summer and fall in tropical regions when growing outdoors. If a houseplant, use an acidic liquid fertilizer mixed into water and applied per label dosage directions across spring, summer and autumn. Do not fertilize in winter.
Prune dead or broken branches as needed with hand pruners. In general, miracle fruit does not require any pruning maintenance.
Harvest the ripe red fruits as needed, picking them off and using them fresh. Do not mass harvest the fruits to store.