Thursday, January 26, 2012

Best Plants for Florida Green Roofs? There are many says MetroVerde!

Best Florida Green Roof Plant?

Metroverde is always working to find suitable plants for Green Roofs in Florida.  For years Northeast Florida has been experiencing a severe drought.  Finding the toughest and most visually appealing is only part of the process.  Habitat value, invasiveness, wind and drought tolerance are other issues we consider.
Green roofs in Florida are harsh places – remember the 7 (or more) H’s:
  1. High Humidity
  2. Hot, hot heat
  3. High desiccating winds (killer)
  4. Hurricanes (not the football team)
  5. Hard Freezes
  6. Horrible temperature swings
  7. Hurtful droughts
  8. Harmful floods
And we all are cautious about irrigating a green roof (I speak as a lawyer – not a botanist here) – our litigious society has already bred a number of legal articles on green building and tort.  Imagine – the issues of:
  • Mold
  • Water damage to interiors
  • Collapse from weight (water is heavy)
  • Bacterial breeding
  • and who knows what else…
So if we choose to acknowledge Florida’s water shortage problem and build a green roof with micro-irrigation or no irrigation at all, then we need to look to plants that:
  1. Can survive the many H’s
  2. Are visually acceptable by the community
  3. May be cost-effective
  4. Are preferably native species (or non-invasive species)
  5. Do not present a fire hazard or contribute too much dry leaf litter
  6. Are low maintenance
  7. Can survive long periods of drought
  8. Can survive twenty inch downpours
  9. Resist fungal infestations
  10. and much more
Two of the most outstanding plants that almost begin to come close to the above requirements are:
1. Frog Fruit (Lippia nodiflora), and
2. Wild Garlic (Allium canadense)
I’ll be posting more data on these two species over the next couple days.  In the meantime – what are your experiences with these species on green roofs?

Green Roof Plant Dwarfed 2 Year Old Allium Canadense

1 comment:

William Gulliver said...

These are insightful information, Kevin. It provides a lot of useful information for homeowners who are planning to install a green roof. Another thing, sedum and sempervivum plant families are also a great choice for green roofing. Sedum doesn't need a lot of water to grow, so it's best for the summer season. On the other hand, sempervivum plants have water-storing capabilities, so these plants can live and grow during the winter season.