Site Analysis for Pollinator Plantings- Part 1- Wallkill Valley Pollinator Pathways

February 18, 2021

By Angela Sisson, Wallkill Valley Pollinator Pathway committee chair

Now is a good time to start planning a pollinator-planting. To do so, it helps to understand a landscape through a site analysis. The more effort applied to learning about a landscape, and what will work and grow well in a particular location, the greater the likelihood of achieving a satisfying result.

Plant identification may need to wait until spring but winter is still a good time to work on a site analysis. Winter reveals the bones or structure of dormant landscapes. Keep in mind that a site analysis is never complete—it’s an ongoing and evolving process, revealing new information with new understanding, including changes to the land over time. Areas which were sunny 10 or 20 years ago may now be shady, or vice versa. Analysis goes on year-round through the seasons and over the years.

To start the process, it’s often useful to have a mental picture of the systems that operate on a landscape. Creating a sketch of the analysis helps develop that mental image. To distinguish between an analysis and a plan or proposed change, the analysis components are often referred to as existing conditions. The existing conditions in any landscape are numerous and varied, often interconnected, systems.

Here are some methods of identifying the existing conditions on your landscape:

Sun/shade: The amount of sunlight an area receives can determine which plants are likely to succeed in that spot. To learn about sun & shade on your site, try to observe the sun’s path. Identify the sunset and sunrise locations at the horizon on the winter and summer solstices because those are the two extremes. The horizon locations for all other dates fall between the extremes. Track the course of the low-winter sun this February. Observe how trees and buildings shade the sun from different areas at different times of day. Identify on a sketch or simply note how much or how little sunlight reaches garden areas. Try to track the sun’s course on a regular or monthly basis. And be patient. It takes time, often a few seasons, to gain an understanding of how sun and shade affect a given site.

Moisture: Like sunlight, moisture can determine which plants are likely to thrive or dominate. Very wet or very dry sites are often considered difficult because they’re on the extremes. But extreme doesn’t need to be difficult nor should it be amended to make it more “normal.” Extreme sites often present an opportunity to plant something out of the norm. A wet, poorly drained depression makes a good place for a rain garden; a dry, sandy or gravelly soil might be a good place for a rock garden or alpine plants.

Soil: Soils can range from prime farmland—level, moist, well drained (what some would consider perfect) to steeply sloped, very rocky, excessively well drained or excessively poorly drained. Soil surveys which identify the different soil types are driven by agricultural usages. Non-agricultural soils tend to sound like a problem which needs solving. But pollinator plantings are driven by existing conditions, not what some consider to be ideal conditions. The concept is to match the plant to the site—also known as right plant, right place—and, where possible, choose native plants over exotic plants. Native plants are important because they host more pollinating insects than do non-native plants.

Knowing and understanding a site’s soil type is essential to the planning process. But this need not be onerous as garden-size areas typically only have one soil type. Detailed descriptions of every soil type can be found in the Ulster County Soil Survey. Descriptions include properties such as drainage, slope, depth to water table, depth to bedrock, soil profile, proportions of sand-silt-clay, and pH, just to name a few. The Ulster County Soil Survey can be found at: https://www.nrcs.usda.gov/Internet/FSE_MANUSCRIPTS/new_york/ulsterNY1979/ulster.pdf

A soil overlay map for Ulster County parcels, along with other environmental overlay maps, can be found on the Ulster County Parcel Viewer: https://ulstercountyny.gov/maps/parcel-viewer/) To see the soil overlay map, click on the Map Layers tab then Geology & Soils.

Slope/Drainage/Topography

Slope and drainage are included in the soil type descriptions referenced above. It’s often obvious how drainage can be a problem for a building or a driveway—but not always clear how to address slope and drainage in the landscape. Although steep slopes or boggy depressions restrict certain land uses, they also help determine the most appropriate plants for a given site. Be aware that drainage conditions will change, sometimes dramatically, over the course of a given year. During the growing season (May through September) soil can absorb more water than it can during the rest of the year. Or more accurately, growing plants absorb water whereas dormant plants do not. For example, a one-inch rainfall which saturates the soil in April may barely penetrate in August.

To understand slope and drainage on your property, observe and note on a sketch where poor drainage occurs and how sloped areas shed water; note whether rainwater channels, which is more erosive, or sheets off a slope. Topographic maps show slopes as contour lines at different elevations. Topo maps also show the direction of the slope referred to as aspect. For example, a slope aspect which is north-facing will support different plants than a south-facing one.

Tune in next month for Part II and a discussion of ecoregions, wildlife, wind, views, structures, history, and plants.

Learn more about ecological garden planning and site analysis here: 

https://www.youtube.com/watch?v=z52twKb1dj0&feature=emb_logo

(Woodstock Pollinator Pathway webinar—Getting to Know Your Landscape: Site Inventory & Analysis)

Become part of the solution and join the Wallkill Valley Pollinator Pathway at:

https://wallkillvalleylt.org/pp/join-pollinator-pathway/

 

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