GROWING GRIT: Low Nutrient Mineral Substrates for Resilient Perennial Planting.
photo by author
In current landscape architectural practice ever-greater demands are placed on designed vegetation. 21st century plantings must be dramatically beautiful, sustain local wildlife, capture and filter storm water, green our roofs, clean our air, and preserve biodiversity all while resources for horticultural maintenance are on the decline. The challenge facing landscape architects today is how to create beautiful, biodiverse, and resilient designed vegetation.
The Low Nutrient Mineral Substrates for Resilient Perennial Planting project will investigate the potential of substrates as an alternative to conventional planting soil. LACF funding will help fund construction, planting, and two years of monitoring of a trial garden. The garden will test the performance of 49 different herbaceous plants and 36 different bulbs on 4 substrates: 2 commercial green roof soils, and 2 different mixtures of recycled concrete aggregate and compost. It is hoped that, if successful, similar substrates and plant communities may become more widely adopted in Canadian landscape practice.
UPDATES
19.02.15 / Final Report updates
( > 90% survival) when regularly irrigated during the first growing season. Substrates with compost fostered the best plant growth, but were more prone to weed invasion. Pure mineral mixtures have shown superior resistance to in-blown weed seed from the adjacent (and very weedy) soccer fields and lawns, but at the expense of plant growth. Most observed weeds were either annual or biennial ruderal species that could easily be managed by 3 or 4 targeted weeding visits per year. The LACF portion of the project is complete.