Frankenflora - the dangers of planting indigenous plants from far away

Dec 20, 2017

To the average gardener it is taken as common knowledge that "indigenous" plants are best. Most commonly the explanation given is that any indigenous plant is water-wise and adapted to the climate. But botanists and ecologists caution us against going blindly "indigenous" without understanding the dangers of mixing locally indigenous plants with "indigenous" plants from other parts of the country or province, creating 'frankenflora'.

The result of mixing the local plants of Cape Town with closely related cousins from elsewhere has been dubbed ‘Frankenflora’. An example, is the mixing of Agapanthus from KwaZulu-Natal with the Agapanthus from Cape Town, says Alex Landsdowne, a Fynbos restoration horticulturist and plant conservation consultant.

“Genetic pollution poses an underrated risk to Fynbos habitats near urban areas. Many indigenous species in horticulture are part of wide spread families or genera that have locally endemic fynbos relatives. When they are planted in gardens near habitats they can pose a risk of spreading or hybridising with our local wild species, and corrupting their unique forms. Agapanthus praecox forms, from summer rainfall KwaZulu-Natal, can hybridise with our unique Fynbos Agapanthus, Agapanthus africanus. The 'Frankenflora' hybrid corrupts the unique Fynbos Agapanthus.”

Agapanthus frankenflora were created on Table Mountain by sunbird cross-pollenating garden Agapanthus in Camps Bay with the locally indigenous Agapanthus of Cape Town.

The question is: why does this really matter? Well, the unique shape and form a plant develops is not simply beautiful to the human eye, but functional and important to plants surviving under local conditions. Plants have been slowly adapting to their local conditions for millions of years, each developing amazing and unique ways of surviving to the soil, water, climate and animals of the area. If a plant on Table Mountain makes ‘frankenflora’ babies with plants from KwaZulu-Natal, those babies could be poorly adapted to conditions of the Cape, or settle in to the area and disrupt the ecosystem balance created by long-standing relationships between local plants, animals and climate.

Moving plants around, even from within the Western Cape region, can create local ‘frankenflora’ hybrids. This happens in the famous protea family, as plants are moved around from one part of the Western Cape to the other. Landsdowne explains:

“Leucadendron coniferum, whilst a local species, is very promiscuous and aggressive. Aside from hybridising with other cone bushes, it can spread to habitats and areas it does not naturally occur, and displace species that occur in special habitats. Fynbos gardening is a well-intentioned effort, but make sure to garden with locally endemic species that would naturally occur in the habitat where you live.”

Check this map for a quick reference to the vegetation type that occurs in your area, and ask your nursery to provide plants from areas, especially if you live close to a conservation area. If you are unsure, ask the conservation officer at your closest conservation area for what plants are vulnerable to hybridisation.

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