Botanical name: Peperomia caperata
Radiator Plant is a compact perennial houseplant that is easy to grow and adapts well to indoor growing conditions. It is native to Brazil where it grows as an epiphyte on trees. The plant is slow growing and grows to a maximum height of 12 in. The leaves are about 1 in. long, heart-shaped and deeply ridged. They are usually green but may have a blush of red and dark-green veins. The flowers are rat-tail flower-heads made up of greeninsh flowers on an upright spike. Radiator Plant is suitable for dish gardens, bottle gardens, terrarium and other situations where space is limited. Many cultivars of Radiator Plant have been developed like Burgundy, Variegata, Emerald Ripple and Rosso among others.
There exists numerous varieties of Peperomias; trailing, bushy and upright ones are available. The foliage may be fleshy, quilted, corrugated, smooth or hairy, green or variegated or even striped like a watermelon. Popular trailing types include Peperomia scandens variegata (Cupid Peperomia), Peperomia glabella (Wax Rivet), Peperomia prostrata (String of Turtles) and Peperomia rotundifolia (Creeping Peperomia). The bushy types grow to about 4-6 in. high and include Peperomia caperata (Radiator Plant), Peperomia argyreia (Watermelon Peperomia), Peperomia hederaefolia (Ivy Peperomia).The upright types have more distinct stems which grow vertically for part or all of the plant's life. They include Peperomia magnoliaefolia variegata (Desert Privet), Peperomia obtusifolia, (Baby Rubber Plant) and Peperomia verticillata (Whorled Peperomia)
Radiator Plant prefers bright to semi-shade (partial shade). It will also thrive in flourescent light. Too little light will result in leggy plants. Keep it away from direct sunshine as it can lead to scorching of the leaves. Learn how to ensure your plant receives the correct light in this guide on understanding light for houseplants.
Water Radiator Plant liberally during the growing season and allow the soil to slightly dry out between waterings. Significantly reduce watering during the cold season to keep the soil barely moist. Avoid waterlogging as it can lead in root-rot. Learn more on how to water houseplants.
Average warmth between 15-260C is ideal for Radiator Plant. Protect the plant from cold draughts as the cause leaf drop. Learn more on temperature for houseplants.
Radiator Plant thrives in a high humidity environment. Mist leaves frequently or set pot on a wet pebble tray to raise humidity. Radiator Plant can also be grown in a terrarium as high humidity can be maintained.
Feed Radiator Plant with a balanced water-soluble fertilizer every 4 weeks during the growing period. Withhold feeding during the cold season as growth is minimal and feeding at this time may lead to fertilizer burn. Learn more on feeding houseplants.
Repot Radiator Plant during the growing season only when the plant has become pot-bound. Use a rich, free-draining soil and a pot one size larger. Ensure the pot has a drainage hole(s) to prevent waterlogging which can lead to root-rot.
Pruning Radiator Plant involves regular removal of dead foliage to maintain the plant neat and tidy. To encourage a bushy, compact growth, regularly pinch of the growing tips. As the plants age, they become straggly. Cut back the stems during the growing season to rejuvenate growth. Learn more on how to prune houseplants.
Radiator Plant can be propagated from seeds, leaf and stem-tip cuttings or by division.
Propagating Radiator Plants from seeds
Sow Radiator Plants seeds at the beginning of the growing season in moist soil. Place the set up in a warm shaded place. Maintain the soil moist until the seeds germinate. Once germinated, move the set up to a cool shaded place and maintain the soil moist until the plants are well established.
Propagating Radiator Plants from leaf cuttings
Leaf cuttings root easily, there is no need for a rooting hormone. Take leaf cuttings from a healthy Radiator Plant. Ensure each leaf cutting has a petiole. Allow sometime for the formation of a protective callous tissue over the cuts. Place the leaf cuttings in a jar of clean plain water and change the water every 7-10 days. Place in warm shaded place until growth begins at the base of the petiole. Allow for substantial growth of the roots and new leaves. Transfer to individual pots and place in a cool shaded place. Maintain the soil moist until the plant is well established. For a fuller plant, plant several plants in one pot.
Propagating Radiator Plants from stem-tip cuttings
Stem-tip cuttings root easily, there is no need for a rooting hormone. Take stem-tip cuttings of about 4-5 in. length from a healthy Radiator Plant. Ensure each cutting has at least 2 sets of leaves. Allow sometime for the formation of a protective callous tissue over the cuts. Insert the cuttings in moist rooting soil. Place in warm shaded place and maintain the soil moist until new growth emerges and substantial growth has been observed. Transfer to individual pots and begin routine care. For a fuller plant plant several cuttings in one pot.
Propagating Radiator Plants by division
Take out the Radiator Plant from its pot and divide it into several sections. Pot up these sections in individual pots. Place in a cool shaded place. Maintain the soil moist until new growth emerges. Allow the new Radiator Plants to be well established before transplanting.
Brown leaf tips and edges in Radiator Plant are due to sudden drop in temperature from cold draughts. Remove all the damaged leaves and keep plants away from cold draughts.
The cause of brown and shrivelled leaves in Radiator Plant is too dry air. Radiator Plant prefers a humid environment. To raise humidity, set the pot on a wet pebble tray. Radiator Plant can also be grown in a terrarium as high humidity can be maintained.
Excess soluble salts in the soil from the water or excess feeding will cause dry shrivelled leaves in Radiator Plant; flush out the salts by running a stream of water through the soil until it comes out through the drainage holes. Repeat several times.
Leggy stems in Radiator Plant are due to low light. Cut back the stems to rejuvenate growth and move the plant to a brighter spot.
Waterlogging of Radiator Plant is the cause of these. This is an indication of Root-rot disease.
Radiator Plant (Peperomia caperata) are non-toxic to humans and pets. The plants are safe to grow indoors.