The authors have no firsthand experience with growing or propagating this species. The information presented is based on recommendations found in the literature and online resources. This highlights the limited documentation and lack of applicable propagation techniques, which in itself poses a challenge and potential threat to the species, looking its current conservation status.

Gladiolus robertsoniae thrives in full sun but can tolerate partial shade. It needs well-draining soil ranging from sandy loam to clay loam, with a slightly acidic pH between 5.5 and 6.5. To promote healthy growth, ensure that compost (humus) is mixed in before planting or applied as a layer of mulch to add nutrients. Sand can be added for improved drainage. To achieve optimal growth, it is essential to maintain even moisture in the soil, watering once a week during spring and summer, especially if rainfall is less than 25 mm. It's best to plant in temperatures of around 16°C to prevent corm rot. When the leaves start to die back at the end of summer, reduce watering and stop watering while they are dormant, during winter. Resume watering in spring.

Gladiolus robertsoniae is best propagated from seeds sown in spring or early summer. After the seed pods dry and crack, seeds can be collected. Carefully extract the seeds and dry them; tissue paper can absorb any remaining moisture. The dried seeds can then be stored in zip-lock bags and kept in the refrigerator until the following spring, or can be sown immediately. For sowing, prepare a free-draining sterile sowing mixture, such as one of coir peat, sand and vermicompost in equal parts, adding a teaspoon of fungicide powder to the mix. Use a 7 cm deep container with drainage holes or seedling trays for planting. Ensure that each seed has adequate space between them. To begin, cover the drainage holes with broken pieces of clay pots and fill the container with the prepared mix until it is a quarter full. Water the mix before placing the seeds on top, then cover the seeds with a thin layer of the same mix, ensuring they are not buried too deeply. Water again gently. If sunlight is harsh, keep the pot in partial shade; if sunlight is normal, place it in full sun. The seeds require continuous moisture; if the mix dries out, the seeds will not germinate, or the bulbs will not grow to their full potential. However, avoid excessive watering, as a soggy mix will result in poor germination. It’s important to keep the mix consistently moist.

When the shoots emerge in spring, apply a liquid fertiliser to increase chances of survival. Avoid high-nitrogen fertilisers, which may lead to excessive leaf growth at the expense of flowers. After the flowering season, allow the flowers to fade and mature into seed pods. Once the pods turn brown and dry out, you can then harvest them. After the seed pods have been collected at the end of the growing season, you can cut back the foliage to ground level unless bulbs are dug up for winter storage. Delaying trimming allows the plant to store more energy in the bulbs, leading to healthier and larger corms for future growth. In very cold climates, Gladiolus species should be treated as annuals, digging up bulbs after the first frost and storing them in a cool, dry place for winter.

Most Gladiolus can be propagated through corms, divisions, cormels, and seeds. To plant Gladiolus, begin by preparing the soil, loosening it to a depth of 300 to 380 mm and incorporating a 50-100 mm layer of aged manure or compost for improved fertility. Select healthy corms and plant them with the pointed end up, with sufficient spacing between each. Gladiolus can be planted in rows for cut flowers, or in groups in borders among other flowers, for the best effect of massed flowers. The corms from the plants can be planted directly in the garden in early spring, after the danger of frost has passed, or started indoors four to six weeks before the last frost date for an earlier growing season.

Most gladioli can be propagated through division, which can be done in autumn (March-May), when all the foliage has withered but before the first hard frost. Lift the corms, shake off the soil, and separate them for replanting. Large corms may bloom the following year, while smaller ones can take two to three years to flower.

Many gladioli can also be propagated through sections, where the corms are lifted and then sliced straight down through the basal plate to create sections. Each section should cure and form a callus before planting in the following spring. Depending on the size of the corm, the large sections may produce flowers as soon as the following year.

Be careful of pests such as thrips (Thysanoptera), which can cause browning and speckling on the foliage. If necessary, these pests can be treated with insecticidal soap or spray. Aphids (Aphidoidea) feed on the sap of tender leaves, emerging spikes and florets. Mites (Tetranychidae) pose a challenge as they infest the corms, causing damage to the leaves and buds. These can be managed by using suitable pesticides.

Diseases such as Fusarium yellows (vascular disease or core rot), caused by Fusarium spp., may result in discrete brown lesions, rotting of plant roots, and leaf infestation. This can be addressed by dipping the corms in a suitable fungicide after harvesting and before storage. Grey mould (Botrytis cinerea) can cause brown spots on leaves. To control this, remove and destroy old flower spikes. A hot water treatment (52° Celsius) of corms, with fungicide added to the water, is effective in eradicating the pathogen.