Isoplexis Growing Guide
Growing Isoplexis canariensis
As its name implies this is a frost tender but beautiful plant from Tenerife in the Canary Islands. It is becoming increasingly common in Cornish seaside gardens and has potential all along the south coast. Elsewhere it is a conservatory or greenhouse plant of some merit although it has easily survived -5°C with us.
I. canariensis is a bushy shrub when young but growing into a spreading tall branched plant of up to 5ft with a semi woody stem rather like an echium. It will grow well in full sun and tolerate partial shade but needs moist well drained soil. As with so many of these Mediterranean plants the killer is wet and waterlogged soil or cold east winds with no protection for the plant.
This plant produces dense racemes of tubular orange-yellow or yellow-brown flowers which can be up to 12in long. The best forms are more orange and yellow than brown. Individual flowers have a two lobed upper lip and are, in maturity, about an inch long. The flowers can appear periodically but are mainly at their best in summer.
Wherever you successfully grow an echium you can also grow this plant. It will not self seed like an echium but the seeds are easily grown.
In the greenhouse the plant needs light, a loam based potting compost and some humidity. In winter the plant needs to be kept moist but dry. Whitefly and red spider mite can be a problem indoors.
