Living plant collections form the core of any botanic garden. Knowledge about the collections is gained through research. Monitoring and documenting an individual plant and its characteristics over time provides base information about that plant and its adaptations to different environmental conditions such as biotic and abiotic stresses.
Horticultural research seeks to improve the quality, sustainability and aesthetics of designed landscapes with the aim of using plants to improve the world around us. The core of the research includes identifying and promoting sustainable horticultural practices such as integrated pest management and use of plants with pest and disease resistance, use of drought tolerant plants for reduced water use, use of climate-adapted plants, using plants attractive to native wildlife, plants for green roofs, etc.
Additionally, when plants are grown in a botanic garden from other regions of the world, it is our responsibility that the introduced plants are monitored for invasive qualities so we do not introduce invasives into a new landscape.
Plant Evaluation and Trial Gardens
Trialing plants to determine their suitability to a climate or specific characteristics such as yield, fruit size, flower color, etc. has been practiced since the transition of humankind from a nomadic hunter-gatherer society to a more static agrarian society about 11,000 years ago. The domestication of our crop plants was the start of the practice of Agriculture and Horticulture. With the expansion of knowledge and development of technology, trialing plants for specific traits through breeding and selections have become standard horticultural practices.
At Denver Botanic Gardens, we are always looking for new plants to enhance our living collections, either through plant collecting expeditions, purchase from commercial sources or exchange with other botanic gardens. The higher the representation of wild collected plants in a botanic gardens’ collections, the higher the value of its collections. To achieve this, we have engaged in wild plant collecting expeditions. We look locally for native plants with ornamental value and internationally in countries with similar habitats and climatic conditions. In the past, many of the new plants have been tested for their ornamental potential and adaptability to our semi-arid region through garden trials. Plants with exceptional value have been introduced for public utilization through Plant Select®, our plant introduction program in collaboration with Colorado State University and the Green Industry of Colorado or through the ‘Grown at the Gardens’ division of our plant sale.
With the introduction of plants from foreign lands comes the responsibility of rigorously testing the plants for invasive potential and water consumption characteristics. With this need in mind, a one-acre horticultural research garden at our Chatfield location was installed in 2007. Research conducted includes multi-year trials to ensure quality of Plant Select® introductions, testing seeds collected by horticulturists for performance and adaptability to Colorado’s climate, assessing invasive potential of new plants before potential introduction, research on water use and soil requirements. The research potential is unlimited with tremendous community benefit. Introduction of a wide variety of plants suited to our region will transform our regional landscapes and make gardening habits more sustainable.
Propagation research is necessary for horticultural as well as conservation purposes. At Denver Botanic Gardens, we acquire plants in our collections that are not often available in horticultural trade, through plant exploration or exchange with other gardens. Propagation methods are generally not known, so we research how to propagate and maintain them.
Seed propagation research includes:
- Developing germination protocols for wild collected seeds that are currently not available in the horticulture trade.
- Developing germination protocols for conservation purposes.
Micropropagation (also known as plant tissue culture) is a method of growing entire plants from small pieces of plant tissue that are genetically identical to the donor plant. This technology can be used to propagate plants in addition to aid the conservation of rare and endangered plants.
We are currently working on four, hard to propagate plants by cuttings. Micropropagation protocols have been developed for these species and they are being produced for large-scale distribution to the green industry. The four plants are:
- Heuchera sanguinea ‘Snow Angel’
- Osteospermum spp. (three cultivars)
- Erodium absinthoides
- Geranium magniflorum ‘La Veta Lace’