INCREASE OF COLD HARDINESS OF ECHIUM PININANA THROUGH NATURAL SELECTION

D. Robinson
E. pininana from the Canary Islands is a highly decorative sub-shrub that grows well in mild coastal areas of Ireland. It is valued for its single spike of blue, purple or rose flowers which can grow from over 1 m to a height of 6 m between February and early June. The plant flowers in its second or third year and, being monocarpic, dies after flowering.

E. pininana is cross pollinated and produces seeds prolifically (in excess of 200,000/plant), which germinate readily and dense carpets of Echium seedlings are commonplace. Plants developing from these seedlings survive most winters but, in some years, a proportion is killed by cold; on two occasions during the last 17 years all plants were killed by low temperatures of -6 C in January. After these severe winters new seedlings develop from the seed bank in the soil.

It seems possible that natural selection from cold stress will, over time, produce a more cold hardy strain ofE. pininana, better adapted to conditions in Ireland. This hypothesis is being tested.

Robinson, D. (1992). INCREASE OF COLD HARDINESS OF ECHIUM PININANA THROUGH NATURAL SELECTION. Acta Hortic. 320, 33-38
DOI: 10.17660/ActaHortic.1992.320.4
https://doi.org/10.17660/ActaHortic.1992.320.4

Acta Horticulturae