Freesia grandiflora is one of the more easily grown species of Freesia. They can be grown in woodland gardens or as pot plants in shade or semi-shade. These plants usually grow in spring and summer, flower in summer and early autumn (October–April), and are dormant during the winter. They can also be grown in climates with a mild winter where they will flower in winter and become dormant in summer. In suitable climates they can be left undisturbed and may multiply and form large clumps.

In the garden, grow F. grandiflora plants in areas with full morning sun and afternoon shade, but they can also tolerate light shade throughout the day. In colder climates plant freesias in sheltered areas, such as under overhanging branches of deciduous trees, or against north-facing walls. They require protection in very cold climates. Avoid excessive shade which will cause plants to fall over easily and reduce flowering. In warmer areas, outside of its natural distribution, avoid full day sun. In pots, place freesias in areas with cool temperatures and lots of light. Most species of Freesia are sensitive to cold but can withstand temperatures close to freezing for a day or two. Plant many plants together to ensure a beautiful display when in flower.

Propagate F. grandiflora plants using seeds or corms. Plant corms or sow seeds in spring, in early September for summer growth, or autumn (April) for winter growth. Sow seeds in a light and well aerated growing medium with perfect drainage, about two to three times the depth of the seed diameter. Dust seeds with fungicide before sowing and sow sparsely. Seeds will germinate in 2 to 4 weeks. Plant the corms 20-30 mm deep with the point facing up. In pots, plant 10 corms in a 20 cm pot or 15 corms in a 25 cm pot. Leave Freesia corms undisturbed during the dormant stage in summer rainfall areas with well-drained soil. In wetter areas or in soil that retains water, remove the corms from the soil and store in a cool dry place. Well-grown mother corms, that have been kept in green leaf for as long as possible, will yield cormlets that mature and flower in the second season after planting. Freesia grandiflora is the only species in this genus where cormlets are formed at the ends of below-ground rhizomes, or sometimes in the axils of leaves. F. grandiflora plants grown from seeds will flower as early as 8 months after sowing or in the second growing season.

Plant F. grandiflora in medium-textured, moderately fertile, loamy or clay soils with a pH between 6.3-7.5. Use soil that is 2 parts coarse sand, 3 parts peat and 7 parts loam and avoid very acidic soil. Water plants twice a week by drenching the soil and adjust according to local conditions. Plants need a lot of water during the growing season, particularly when in bud and flower, but never let the soil become waterlogged. Water on the ground or at the base of the plant, not on the leaves. Stop watering just before the leaves are completely desiccated. Take care when feeding as freesias are very sensitive to too much salt in the soil (from high sulphate fertilizers), which causes the soil to become too acidic. They are also sensitive to too much nitrogen.

Possible pests of Freesia plants include aphids, mealy bugs, thrips, red spider mites, rodents that eat the corms, botrytis blight, fusarium corm rot and viral infections (freesia mosaic virus).