Swedish ivy (Plectranthus australis) is neither Swedish
nor an ivy, and some authorities list it under another species (P.
verticillatus). The genus name comes from the Greek words
for spur (plectron) and flower (anthos), referring
to the spur-shaped flowers. These tubular white small
flowers that appear on stalks at the ends of stems aren’t
The species name (australis) means southern, referring to
its origin in southern Africa. It is not from Sweden, but
became popular there as a houseplant. And it does trail,
resembling an ivy. This common member of the mint family is
related to the coleus and, like members of this family, has square
stems in cross section.
Give a Swedish ivy bright indirect light, but not direct sun for too long as this can burn the leaves. An east or even north window works well, as does a plant grow light for at least 12 (preferably 16) hours a day. Too little light and plants will become “leggy.”
If in doubt don’t water, as these would rather be too dry than too wet. Keeping plants waterlogged is the main cause of death. Leaves yellowing indicate that they’re overwatered. If leaves wilt and turn soft and dull green, give more water. Inexpensive water meters from hardware and garden stores can help if you’re having trouble deciding on watering.
When plants are actively growing—usually in spring and summer—fertilize every couple weeks, but only with half-strength fertilizer of your choice. Also when they’re growing, give them temperatures of 70 to 75 degrees (F) if possible. Other times of year, cooler temperatures of 60 to 65 degrees are best. Don’t let plants get below 50 degrees or leaves may turn black. A somewhat constant temperature between 60 and 75 degrees year round works well, too, for them.
Swedish ivy grows best with high humidity, but it tolerates and
usually grows fine in the lower humidity found in most homes and
buildings, particularly during winter heating season. The
main pests to watch for are brown scales and white
mealybugs. If you see these, rub them off with a cotton swab
dipped in rubbing alcohol. Giving plants a shower
periodically helps to keep them dust free, and to keep pests at
bay, as well as giving them more humidity.
Sometimes, particularly in dry indoor rooms, these plants may
attract spider mites. Look for the tell-tale webbing between
stems and leaves, and under leaves. You may need a
magnifying glass to see them. Use a special miticide spray
for these pests.
Swedish ivy plants can be rather potbound. If repotting, or
potting small plants you may have purchased into a larger pot or
hanging basket, use a peat- or organic-based potting soil.
If plants get too long or leggy, prune them back to the desired
length. You can then cut stems with leaves into five- to
six-inch sections, removing the lower leaves. Place these
either into a vase of water, potting mix, or vermiculite or
perlite. In a few weeks plants should be rooted, as they are
easy to root from such stem cuttings.
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