Department of Public Works Staff Memorandum
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DEPARTMENT OF PUBLIC WORKS STAFF MEMORANDUM DATE: July 22, 2014 TO: Horticulture, Environment, and Beautification Committee CC: Sharon Stott, Assistant to the City Administrator FROM: Matt Wohlberg, P.E., City Engineer SUBJECT: Landscaping Plan Review Dam and Lake Rehabilitation Project Creve Coeur Golf Course City staff seeks the advice and recommendation for approval from the Horticulture, Environment, and Beautification Committee (HEB) for the landscaping plan proposed as part of the Dam and Channel Rehabilitation Project at the Creve Coeur Golf Course. The project involves the removal and replacement of the failing existing dam at the south end of the golf course lake system. The City hired a team consisting of Intuition & Logic (lead design and permitting), Geotechnology, Inc. (dam design), and SWT Design (landscape architecture) to design the project. The landscaping proposal is the product of several iterations of project scoping and design, and it aims to achieve several goals: 1. Beautification, within reason. The restoration of the site following the dam work will need to look good, because the project is at the golf course. The initial plan provided by SWT Design heavily landscaped the dam, and City staff felt that this was not in line with the direction provided by City Council – namely to focus the beautification efforts on the areas that are most visible. Few will notice or focus on the south side of the dam, so beautification efforts are limited in this area to establishing a riparian corridor along the creek. The intent of the current proposal is to have a clean and attractive presentation. 2. Low-maintenance. The City does not want to create an ongoing maintenance issue, so the proposal includes plantings that are generally self-sufficient. 3. Native plantings. Nearly all of the proposed plantings are native to Missouri. As such, this should provide a natural look (in line with goal #1) that is easy to maintain (goal #2). The proposed landscaping plan includes three main aspects: aquatic plantings at select locations around the lake, shrubs to surround the overflow structure at the dam, and riparian plantings to line creek south of the dam. The remainder of the restoration is proposed to be turf grass. The general locations of the planting areas are illustrated in the attached Planting Plan, and details of the individual plants are provided in the attached photos and summaries from the Missouri Botanical Garden. Page 1 of 1 M:\Projects\14522 Dam and Lake Rehabilitation\1 - Design\Approvals\2014-07-23 - HEB\2014-07-23 - Dam and Lake Rehabilitation Project - HEB Recommendation.doc City of Creve Coeur, Missouri Dam and Channel Rehabilitation Project Figure 1: Silky Dogwood (aka Swamp Dogwood) Figure 2: Silky Dogwood (aka Swamp Dogwood) Riparian Plantings Cornus amomum subsp. obliqua - Plant Finder Page 1 of 2 Home Support the Garden Members Shop Volunteer Jobs Media Contact Search Visit Things To Do Learn & Discover Gardens & Gardening Sustainability Plant Conservation Plant Science About Gardens & Gardening > Your Garden > Plant Finder Like Plant Finder? Help us Cornus amomum subsp. obliqua improve and expand it! Back to Previous Page Plant Finder Lawn, Landscape & Common Name: swamp dogwood Garden Design Type: Deciduous shrub Edible Gardening Family: Cornaceae Advice, Tips & Resources Native Range: Eastern and central North America Plants of Merit Zone: 4 to 8 Sustainable Gardening Height: 6.00 to 12.00 feet Gardening Education & Spread: 4.00 to 10.00 feet Classes Be the first to comment on this Bloom Time: May to June Visit the Center for Home plant Bloom Description: Yellowish-white Gardening More Images Sun: Full sun to part shade Gardening Help Site Map Species Native to Missouri Water: Medium to wet Maintenance: Medium Flower: Showy Gardening Help Search Attracts: Birds Fruit: Showy Search Garden locations Culture Grow in average, medium to wet, well-drained soils in full sun to part shade. Prefers moist, organically rich, slightly acidic soils in part shade. Tolerates close to full shade. Benefits from a 2-4” mulch which will help keep roots cool and moist in summer. Branches that touch the ground may root at the nodes. When left alone, this shrub may spread to form thickets. Noteworthy Characteristics Cornus amomum subsp obliqua is synonymous with and formerly known as Cornus obliqua. It is a medium-sized deciduous shrub that is typically found in moist lowland areas, swamp borders, floodplains, shrub wetlands, wet meadows/prairies and along streams and ponds in Eastern and Midwestern North America (New Foundland to Ontario south to Oklahoma, Arkansas and Virginia). In the words of the Royal Horticultural Society, this subspecies primarily differs from species plants by having "a looser habit". Twigs and leaf undersides have silky hairs, hence the common name of silky dogwood. This dogwood typically grows to 6-12’ tall with an open-rounded form. Tiny yellowish-white flowers (showy petal-like white bracts are absent) in flat-topped clusters (cymes to 2.5” across) bloom in late spring to early summer. Flowers give way to attractive blue to white berry-like drupes that ripen in late summer (August). Birds are attracted to the fruit. Oval to elliptic, medium green leaves (2-3” long) have conspicuous veins. Attractive fall color is usually absent. Twigs are purplish brown in spring, and have a distinctive brown pith. Genus name comes from the Latin word for horn (reference to hard wood). Problems No serious insect or disease problems. Plants are susceptible to scale. Additional insect pests include borers and leaf miner. Infrequent disease problems include leaf spot, crown canker, blights, root rot and powdery mildew. Garden Uses Good shrub for moist to wet areas of the landscape. Not overly ornamental. Somewhat wild and unkempt for placement in prominent areas. Good selection for moist woodlands, naturalized areas, along steams/ponds or for erosion control. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=279... 7/16/2014 City of Creve Coeur, Missouri Dam and Channel Rehabilitation Project Figure 3: Four seasons of the Red Twig Dogwood (aka Red Osier Dogwood) Figure 4: Red Twig Dogwood (aka Red Osier Dogwood) Riparian Plantings City of Creve Coeur, Missouri Dam and Channel Rehabilitation Project This page intentionally left blank. Riparian Plantings Cornus sericea 'Baileyi' - Plant Finder Page 1 of 2 Home Support the Garden Members Shop Volunteer Jobs Media Contact Search Visit Things To Do Learn & Discover Gardens & Gardening Sustainability Plant Conservation Plant Science About Gardens & Gardening > Your Garden > Plant Finder Like Plant Finder? Help us Cornus sericea 'Baileyi' improve and expand it! Back to Previous Page Plant Finder Lawn, Landscape & Common Name: red twig dogwood Garden Design Type: Deciduous shrub Edible Gardening Family: Cornaceae Advice, Tips & Resources Zone: 3 to 8 Plants of Merit Height: 6.00 to 10.00 feet Sustainable Gardening Spread: 6.00 to 10.00 feet Gardening Education & Bloom Time: May to June Classes , See Comments Bloom Description: White Visit the Center for Home More Images Sun: Full sun to part shade Gardening Tried and Trouble-free Water: Medium to wet Gardening Help Site Map Recommended by 5 Professionals Maintenance: Medium Suggested Use: Hedge, Rain Garden Flower: Showy Gardening Help Search Leaf: Good Fall Attracts: Birds, Butterflies Search Fruit: Showy Other: Winter Interest Tolerate: Deer, Erosion, Clay Soil, Wet Soil Garden locations Culture Best grown in organically rich, medium to wet soils in full sun to part shade. Tolerant of a wide range of soils, including swampy or boggy conditions. Best red stem color occurs on young stems. Although pruning is not required, many gardeners choose to remove 20- 25% of the oldest stems in early spring of each year to stimulate growth of new stems which will display the best red color. As an alternative to annual pruning, some gardeners prune all stems close to the ground in early spring every 2-3 years to renew. Any loss of flowers through spring pruning is not terribly significant since the small flowers of this dogwood are rather ordinary. Noteworthy Characteristics Cornus sericea, commonly known as red twig dogwood or red osier dogwood, is an upright-spreading, suckering shrub that typically grows in the absence of pruning to 6-9’ tall with a slightly larger spread. With the exception of the lower midwest and deep South, this species is native to much of North America where it is typically found growing in wet swampy areas, wetland margins or along lakes and rivers. Ovate to lanceolate, medium to dark green leaves (2-5” long) acquire interesting shades of red to orange eventually fading to purple in autumn. Reddish stems turn bright red in winter and are particularly showy against a snowy backdrop. Tiny, fragrant, white flowers appear in flat-topped clusters (cymes to 2.5” diameter) in late spring, with sparse, intermittent, additional flowering sometimes continuing into summer. Flowers give way to clusters of whitish (sometimes with a bluish tinge) drupes in summer. Fruit is quite attractive to birds and is generally considered to have as much if not more ornamental interest than the flowers. Synonymous with and formerly known as Cornus stolonifera. Red stems somewhat resemble the reddish stems of some osier willows, hence the common name of red osier dogwood. Some cultivars of this species (e.g., C. sericea 'Flaviramia') have yellow stems. 'Baileyi' is a redtwig dogwood cultivar. It is a rapid-growing, multi-stemmed, deciduous shrub which grows to a maximum size of 6-10' tall with a loose, rounded habit. It lacks the stoloniferous, spreading habit of the species and is listed in Hortus Third as Cornus sericea forma baileyi. Some nurseries sell the plant as Cornus baileyi. The outstanding ornamental feature of this plant is its bright red winter stems. Leaves (2-4" long) have curling hairs underneath.