Rhode Island Stormwater Design and Installation Standards Manual

Rhode Island Stormwater Design and Installation Standards Manual Public Workshop Vegetation Management and Maintenance January 19, 2011 Horsley Witten Group, Inc.

Introduction • Plant Design • Plant Selection • Plant Care Horsley Witten Group, Inc.

Design Basics Plant Design • Establish a preferred design approach • Understand site constraints and conditions • Select appropriate plant species • Prepare planting design plan • Keep it simple Source: http: //plants. usda. gov Horsley Witten Group, Inc.

Planting Plan Horsley Witten Group, Inc.

Plant Care Scheduled Maintenance Horsley Witten Group, Inc.

Pruning and Plant Thinning – Maintain plant health and vigor – Removal of dead or broken wood – Encouragement of flowering and fruiting – Control of overgrowth of plant material Image courtesy of Rutgers New Jersey Agricultural Experiment Station Horsley Witten Group, Inc. Plant Maintenance • Why Prune?

Pruning and Plant Thinning Plant Maintenance • Trees and large shrubs – Wait at least 1 year – Remove dead, damaged, or diseased branches only – Prune in late winter/early spring – Never prune behind the branch’s bark ridge Horsley Witten Group, Inc.

Pruning and Plant Thinning Plant Maintenance • Shrubs – Prune once the shrub approach mature height – Immediately after flowering, unless specified otherwise – Pruned back damaged/diseased limbs – Do not leave stubs Horsley Witten Group, Inc.

Pruning and Plant Thinning Plant Maintenance • Perennials and grasses – Leave dry standing stalks during dormant months – Cut back dead foliage late winter/early spring – Remove cut foliage from bioretention area Horsley Witten Group, Inc.

Mowing Plant Maintenance • Not necessary or recommended for raingardens/bio. • Allow plants to flourish • When side slopes seeded with native grass – Mow once or twice per year Horsley Witten Group, Inc.

Mowing Plant Maintenance • Use a mulching blade or point the mower away from the bioretention area – Fresh grass clipping are high in nitrogen – Grass clippings can compromise pollutant removal effectiveness Horsley Witten Group, Inc.

Plant Maintenance Mowing Horsley Witten Group, Inc.

Plant Maintenance Mowing Horsley Witten Group, Inc.

Weeding • Why Weed? Plant Maintenance – Control invasive plants – Promote native non-invasive plant growth • When to weed? – April thru October – Monthly Horsley Witten Group, Inc.

Weeding Plant Maintenance • Do not use chemical herbicides • Remove by hand • A list of invasive species can be found at: http: //www. rinhs. org/resources/ ri-invasive-speciesresources/invasive-list/ Horsley Witten Group, Inc.

Weeding Plant Maintenance • Be on the lookout for these invasive species: Photo by Betty Ann Kelly Oriental Bittersweet Japanese Knotweed Horsley Witten Group, Inc.

Weeding Scotch Thistle Multiflora Rose Horsley Witten Group, Inc. Plant Maintenance • Be on the lookout for these invasive species

• During the first few weeks after planting – To establish and maintain healthy grass • During the 1 st year – Plant and grass growth • After the 1 st year – Drought periods only Photo courtesy of Rutgers New Jersey Agricultural Experiment Station Soaker hose Horsley Witten Group, Inc. Plant Maintenance Watering

Disease and Pest Control Plant Maintenance • Monitor plants for damage • Pesticides should be avoided • Adopt an Integrated pest management approach – – – Biological Physical Mechanical Cultural Chemical controls Horsley Witten Group, Inc.

Plant Replacement – Was the weather drastically different than the conditions the basin was designed to retain? – Was flow too fast through the basin, damaging health? – Is flow being incorrectly discharged from the rain garden? Photo by Linda Brazaitis Horsley Witten Group, Inc. Plant Maintenance • After the first season, look for the following plant health indicators:

• Replace dead or diseased plant material • Place plant in the same location • Re-seed the side slopes Photo courtesy of Rutgers New Jersey Agricultural Experiment Station • Best time to replant: – Early to mid Fall – Early to mid Spring Horsley Witten Group, Inc. Plant Maintenance Plant Replacement

The first Rain Garden in Virginia, located in a turning circle in front of St. Stephens School, Horsley Witten Group, Inc. Alexandria.

St. Stephens Rain Garden- 5 years later. Horsley Witten Group, Inc.

2000 It doesn’t take long 2003 Horsley Witten Group, Inc.

Fertilizing Plant Maintenance • Fertilization should not be necessary – Compromises pollutant reduction effectiveness – Leads to weak plant growth – Promotes disease and pests – Inhibits soil life Horsley Witten Group, Inc.

Questions? Horsley Witten Group, Inc.