Plectranthus hilliardiae is a decorative plant and could become a popular plectranthus in the horticultural trade, but it is not as easy to grow as many other species of Plectranthus. It requires high humidity and warm, subtropical temperatures to thrive. This plant can be grown in light or deep shade with moderate watering and can be either planted in the garden or as potted specimens. Plant them densely together for thick and compact foliage in garden beds. This species performs very well in well-drained, composted soil and requires occasional water in summer. Feed with an organic fertilizer to improve the plant quality. Pinch out spent inflorescence to encourage new growth and buds in late winter. Prune the tips of the branches to control and encourage growth. Few pests attack these plants.

Plectranthus hilliardiae is best propagated vegetatively by means of tip and stem cuttings, in summer. Take cuttings from a healthy and disease-free mother stock at the coolest time of the day, preferably morning, when the plant is fully vigorous. Use a well-drained soil mix, such as 2 parts sifted fine bark, 3 parts perlite and 1 part sifted compost (2:3:1); add a thin layer of coarse bark at the bottom of your seed tray for better drainage. Prepare the cuttings by cutting under the nodes of the stem at 70 to 100 mm, remove a third of the leaves from the bottom to reduce loss of water while rooting. Rooting hormone is necessary to promote root growth, apply it at the bottom of the node. Keep the cuttings in a warm, humid area with good air movement and keep the soil moist, but not wet. Rooting will take place after 3–4 weeks and once well-established, transplant cuttings into containers and water regularly until they are fully grown. Established plants can be transplanted into bigger containers or into the garden.