There are a lot of great funding opportunities that community groups in Seattle can use to get their projects off the ground. Below is a list of a number of public grantors that often give money to park improvement projects. You can also check the City of Seattle's new Grant Portal.

City of Seattle Resources:

Department of Neighborhoods
Neighborhood Matching Funds - Small and large project funding is available to support projects including design or build. They include:
Small Sparks Fund
Small and Simple Projects Fund
Large Project Fund

Seattle Department of Transportation
Neighborhood Projects Fund - These support neighborhood improvements to streets and parks.
SDOT Safe Routes to School Mini-Grant Program - Provides grants up to $1,000 to schools and community groups for programs that encourage walking and biking to school or improve walk and bike safety.
Tree Planting Program - Seattle Department of Transportation is looking for places to plant new street trees. Apply here to request a new tree in your neighborhood.

Seattle Public Schools
Self Help Program - Any project to improve District school buildings or grounds carried out by a group other than the District Facilities Department.

Seattle Public Utilities
Grant Programs - Seattle Public Utilities offers many grants for projects that promote waste reduction and/or clean waterways, including:
School Recycling & Waste Reduction Grants - Grants to implement or expand food waste composting, recycling and waste reduction programs in K-12 public and private schools in Seattle.

Department of Parks and Recreation
Parks and Green Spaces Levy Opportunity Fund - Second round process is due to start mid 2012.

Office of Economic Development
Neighborhood Business District Program

Office of Arts & Cultural Affairs
Neighborhood & Community Arts program - NCA supports neighborhood groups that produce recurring festivals or events that promote arts and cultural participation, build community and enhance the visibility of neighborhoods through arts and culture.

Department of Information Technology
Bill Wright Technology Matching Fund - Supports community's efforts to close the digital divide and encourage a technology-healthy city.

Office of Sustainability and the Environment
Trees for Neighborhoods - helps Seattle residents plant trees in their yards and along their streets.

King County Resources:

King Conservation District Grant Program
King County Environmental Grants & Awards

Federal Resources:

Federal Highway Administration Programs

Environmental Protection Agency
Environmental Protection Agency Grants & Fellowship Information

National Parks Service
Rivers, Trails & Conservation Assistance Program - The Rivers, Trails, and Conservation Assistance Program is the community assistance arm of the National Park Service. RTCA supports community-led natural resource conservation and outdoor recreation projects.

Washington State Resources:

Washington State Department of Ecology
Washington State Department of Ecology Grants & Loans

Private Resources:

Seattle Foundation Grants
The Seattle Foundation has grant programs for organizations within King County that contribute to a healthy and vibrant community through programing. Their grant program focuses on environmental and neighborhood & community based organizations among others.

Resources for Environmental Restoration:

Green Seattle Partnership has compiled a list of grants and granting organizations geared toward environmental restoration.