Written by: Mary Wang
There is a lot of information on gardening with native plants which can sometimes make creating a native garden or adding natives to an existing garden seem overwhelming and confusing. I am vurrently very aware of this fact as I’m in the process of transitioning my garden from a lawn, surrounded by pines and rocks, into a more diverse, drought tolerant landscape containing mainly native plants.
There are many reasons to consider gardening with native plants. Native plants are adapted to the surrounding environment. They have evolved to grow in a particular region and as a result are resilient to local weather variations, climate conditions and soils. They have also evolved with local wildlife and sustain that wildlife by providing food and shelter. As large swaths of landscape become urbanized there is wide disruption to the ecosystem caused by the loss of native plants. If we create landscapes using native plants around homes, commercial buildings and roads, we can provide areas and corridors that support and strengthen the native plant and wildlife community. By doing this we can potentially help mitigate the extinction of species. From the human perspective of time and money, native landscapes tend to save both in the long run. Because native plants have evolved to local conditions and are suited to these conditions once they are established, they require less irrigation and fertilization, as well as a reduction in other maintenance tasks such as pruning and mowing. As a bonus native landscapes can be extremely beautiful. They mesh with the surrounding environment and can integrate structures seamlessly into these surroundings. When done well, native gardens can increase the curb appeal of your home and potentially its value when sold. An additional benefit to native landscapes is they provide wonderful places for children to wander and explore. Amazing surprises and discoveries exist around every turn and in every nook and cranny. A native garden gives children a window into their natural surroundings, allowing them to get to know it, love it, discover how it sustains them, and how they can protect it.
In Colorado, the landscape usually is divided into five broad vegetative zones that are defined by their altitudes. Within these areas the climate remains relatively consistent, although variations do exist creating microclimates. These microclimates often support unique or unexpected species for that particular zone. The five zones in Colorado are the Grasslands/Semi-desert Shrublands, Foothills, Montane, Subalpine and Alpine. As I live in Pueblo, Colorado I am particularly interested in plants of this region so I will discuss three trees that are attractive and suitable for home gardens as well as important parts of the local environment.
Gambel’s Oak or Quericus gambelii is a deciduous tree. It is the most abundant oak in the state and is often found in dense groves. It grows approximately 25-30 feet in height, although exceptions do occur with reports of some reaching 50 feet in height. The average spread of the tree is about 12 feet. The tree’s leaves measure approximately 5 inches in length, and are characterized by three to four deep lobes around the central vein. The leaf color tends to be bright green on top with a light green underside. In autumn the leaves turn to a reddish brown before dropping. The tree produces acorns which are an important food source for deer, small mammals and birds. The tree itself provides cover and nesting sites. In addition to birds and mammals Quericus gambelii is a food source for Colorado Hairstreak Butterfly larvae. In the spring these caterpillars feed on the young leaves. Quericus gambelii is tolerant of a wide variety of soil types, requires full sun to part-shade and is also tolerant of low water conditions. It’s usually found at lower elevations (4,000-8,000 feet).
Pinyon Pine or Pinus edulis is an evergreen, two needle pine. The needles are 1-2 inches long with a slight curve. The new growth tends to be dark- green turning yellowish- green with maturity. The tree is characterized by a pyramidal or spreading rounded shape that grows anywhere from 10-30 feet high. Pinus edulis most commonly occurs at lower elevations (4,500-7,500 feet). It is a species very tolerant to low water conditions and is found in ranges where annual precipitation is 12- 18 inches. It grows in sun to part shade and does well in a variety of soil types, however, it has a low tolerance to Calcium carbonate (CaCO3). Pinus edulis is an important food source to numerous animals. Its seeds are enjoyed by many mammalian species; humans collect and sell them as a food crop. Songbirds, Pinyon Jays and Quail also enjoy the oily seeds. Small pinyons are used as Christmas trees and incense is made from crushed pinyon cones.
American Plum or Prunus americana is an attractive deciduous tree. The tree is broad crowned, with branches that spread above a short trunk. The trunk is covered in scaly, black bark. In the spring the branches bloom with fragrant white flowers. The fruit ripens in summer becoming bright red and in the fall the leaves range in color from a striking red to light yellow. This smallish tree grows about 15 feet tall by 8 feet wide. Unlike the two previous trees Prunus americana has medium level water needs and enjoys moist, rich, well drained soils. Unlike Pinus edulis, Prunus americana has a high tolerance to Calcium carbonate (CaCO3). It grows in a wide variety of light conditions tolerating sun, part-shade to shade. It can be found growing along woodland edges, stream banks and in pastures. Prunus americana gives valuable nesting cover to birds and is a host to many butterflies. It is of extreme value to native bees which are attracted to the trees in large numbers. Prunus americana is often grown for erosion control as it can spread by root sprouts. It’s fruit has a tough, sour skin but is sweet and juicy inside making it an excellent fruit for jams, jellies, preserves and pies. Caution does need to be exercised with this tree as it has thorns or prickles and all parts of the tree except the flesh and skin of the plums contain hydrocyanic acid.
References:
1) https://www.wildflower.org/plants/result.php?id_plant=quga
2) https://conps.org/the-gambel-oak/
3) https://www.wildflower.org/plants/result.php?id_plant=pied
4) https://www.wildflower.org/plants/result.php?id_plant=pram
5) https://extension.colostate.edu/docs/pubs/native/SESm.pdf
6) https://extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf
7) Manual of Woody Landscape Plants, Their Identification Ornamental Characteristics, Culture, Propagation and Uses, 4th edition 1990 By Michael A. Dirr, Department of Horticulture, University of Georgia
8) https://www.butterfliesandmoths.org/species/Hypaurotis-crysalus
9) Colorado Plant Ecosystems.pdf, CMG GardenNotes #511, McMulkin, L., Potts, L. Parmenter, D. Shonie, I., and Whiting D., CSU Extension, Revised August 2010