Gardening Resources and Native Plant Sale FAQs


Learn how to make the most of your native plantings at home.

Good Things to Know

THE PLANT SALE IS OFFICIALLY CLOSED

JOIN US FOR THE BEST VOLUNTEER GIG OF THE SPRING!

The Great Swamp Watershed’s community-run plant sale needs volunteers for 2-hour time slots at GSWA HQ on Tempe Wick Road, Monday May 1 through Friday May 5. BRING YOUR FRIENDS! Signing up for multiple slots is welcome, go to bit.ly/3MFHewS


IMPORTANT NEXT STEPS FOR PLANT PICKUP LOCATION SELECTION – We are aware that the PLANT PICKUP LOCATION SELECTION option was not working properly for some purchasers. Please be on the lookout for an email from GSWA in the next 7-10 days prompting you to select your preferred pickup location.

GSWA 2023 Native Plant Sale Webinar Recordings
The Jan 17, Feb 21 and April 3 recordings are available for replay. NOTE: Our webinars have been recorded and archived for private replay. To request a link, contact plantsale@greatswamp.org.

Why we need native plants
Native plants provide necessary habitat to sustain populations of native insects, birds and other wildlife. The more native flowers, shrubs and trees in our landscape, the more the local wildlife that evolved with these plants will thrive. Research has shown that when a landscape has too few native plants, the population of many species seriously declines. Even though some non-native plants may even look like similarly-named native cousins and may offer flower nectar and other services, they fail to adequately support native wildlife.

Doug Tallamy of the University of Delaware translates complex ecosystem science into a clear and simple explanation of why native plant communities are essential. Excellent webinars, articles, books and links to many helpful resources are available at: Homegrown National Park.

Cultivating Wildlife Conservation with Native Plants” presented by Desiree Narango PhD, research co-author with Tallamy now at Univ. of Massachusetts Amherst, is a particularly outstanding 48 minute webinar recording. This is an easy-to-understand summary of the scientific facts and logic behind the guideline that 70% native plants biomass is a minimum threshold for sustainable bird populations.

Are you on the Native Plants MAP? Please help build out Pollinator Pathways and recruit your neighbors and community to join. EVERY native plant pollinator garden contributes insect and bird habitat connecting across yards, neighborhoods, parks and regions!


“Quick Start” Gardening Guides

GSWA Plant Sale Garden Kit Manuals – Download the manuals now to help you prepare your gardens.

Going Native: A Guide to Landscaping with Native Plants in Northern New Jersey (download PDF here)

    • This printable guide from Jersey-Friendly Yards crisply summarizes locally appropriate native plant species . For each plant it includes height, bloom time and color, sunlight requirements, soil and moisture requirements, wildlife support, and deer resistance.
    • It also includes 8 tips towards success and links to several very helpful sites if you want to go deeper.

Creating Your Own Native Garden Design

Know your garden style preferences on the spectrum from formal to naturalistic to wild.
Native plant pollinator gardens can accommodate any point on this spectrum. 

    • Take few minutes for virtual stroll at the  Mt. Cuba Center in Delaware to visit their formal garden, their naturalistic landscaping, and their wild meadows (in spring, summer, and fall!).
    • You do not need to compromise your landscape goals to use only native plants

Resources to help you design YOUR garden
Pollinator plants can be used in gardens of any size, from small containers to huge meadows and in any place, from high rise balconies to urban and suburban yards and parks.

Be a Pollinator Plant Ambassador!
Design pollinator Gardens for front yards and public places to be native plant demonstrations that delight and enroll the community


Keystone Plants for Your Landscape

Wildflowers alone are not enough. Across the US, only 14% of native plants are the hosts for 90% of caterpillars, with trees and shrubs being the most important. These “Keystone” plant groups of species (genera) are particularly important to maintain insect populations and diversity. 

Plant native trees and shrubs- they lead the list of keystone plants!

Keystone Native Plants for Eastern Temperate Forests

Table from “Keystone Native Plants for the Eastern Temperate Forest” by the National Wildlife Foundation Keystone Plants by Ecoregion

Woody Plant Shopping Lists based on Jersey Friendly Yards.


“Soft Landings” are required for complete pollinator life cycles

“Soft landings” in year-round leaf litter and ground cover are required by many species of butterflies, moths, bees, fireflies and other important insects  to complete the egg, larval, and/or pupal stage of their life cycle. Some insect adult species even use this ground layer habitat to overwinter.

    • Please leave as much soft landing leaf litter and plant cover in your gardens as you can. Cleaning your garden beds too much removes habitat that many insect species must have for complete life cycles that sustain future generations.
    • Provide garden or wild soft landing areas underneath your trees and shrubs. Many of the hundreds of species hosted by trees and shrubs drop from the branches to the ground for their next stage of life. If they drop into lawn, they will not survive.
    • Learn more: https://www.pollinatorsnativeplants.com/softlandings.html

Pledge to NOT plant Invasive Species and replace them where you can!

Invasive plants are non-natives that not only can thrive almost anywhere and are untouched by local insects (two features attractive to gardeners and nurseries) but that also propagate TOO well. Their successful propagation allows them to escape our gardens to cause ecological and economic damage across wide expanses of private and public open space.  They dominate areas of the landscape and push out the native plants, from small flowers that can no longer sprout to huge trees that are choked and smothered by vines. The spread of invasive plants dramatically reduces the habitat required for insects, birds and other wildlife.

    • 47% of invasive plant species came via horticulture, even though invasive species are only a small percentage of the many non-native species that are sold.  
    • Bradford Pear trees, Chinese Silver Grass (Miscanthus), Butterfly Bush, Burning Bush, Asian Wisteria, Oriental Bittersweet and Japanese Barberry are just a few of these invasive species that are causing major damage. 
    • The New Jersey Invasive Species Strike Team (NJISST) maintains the NJ “Do Not Plant List”  of invasive species that are widespread or threatening to become widespread in New Jersey.
    • New Jersey Invasive Species Info Center
    • NJ Invasive Species Do Not Plant List
    • PTNT Plant This, Not That, a guide to the benefits of growing native plants

PLEASE ONLY PLANT SPECIES NOT ON THIS LIST


Preparing a new native plant bed in an existing lawn

Minimize soil disturbance. Native plants grow best in simple un-amended soils. 

There’s no better way to start than with Sheet Mulching. Also known as the “lasagna method”, sheet mulching is a back-saving “no-dig” strategy that smothers unwanted weeds and grass by blocking out sunlight, allowing everything to die and decompose without lifting a shovel and importantly, without disturbing the soil, stirring up the weed seed bank, or damaging the roots of nearby trees and shrubs.

    • Start by running your mower or cutting back the ground cover over the area you’d like to transform. If you’re creating a new bed, use your garden hose or a length of rope to create the outline of the garden.
    • Once you’ve got a shape you like, begin covering the area with tapeless clean cardboard or 5 to 8 sheets of newspaper. (Use plain cardboard or regular newsprint, but don’t use the glossy pages.) Overlap the edges of the cardboard and/or paper to close up gaps so that the turf is solidly covered. And keep water handy so you can wet it down as you go, so it won’t blow away.
    • Once the cardboard or paper is laid out and wet, cover it with about 3-4 inches of composted mulch. 
    • If there are tree roots underneath (they often extend 2x as far as the longer branches), use a sharp point to poke a bunch of holes to allow water and air to easily penetrate during the months before the sheets decompose (especially if you are using cardboard sheets). 
    • Once it is ready, plant right through the sheet mulch, into the soil.

Minimum effort, minimum soil disturbance, and a year ahead with weeds suppressed. An easy method for great results .

Note: It can take one season or more  to completely smother undesirable plants beneath the mulch, depending on how robust they are. You can still plant through earlier, but remove any live weed roots you come upon and be ready to do spot weeding later.


Planting your plugs

    • Until your plugs are in the ground, make sure they stay moist (but not drowned).
    • The only tool you need is a garden knife, trowel, or light-weight one hand pick.
    • Lay out where you want to place which plugs.
    • Dig a hole the plug will fit.
    • Remove the plug gently from the plug strip. Pulling hard from the top may tear the plant from the roots. Squeeze around the sides to loosen it and push it up from the bottom or use a narrow spatula.
    • Plant the plug so that the top of the plug lines up with the top of the soil and tamp the soil around it so that the dirt is packed against the roots.
    • Water it in.

Simple Principles for Native Plant Garden Maintenance

During the first season as the plants get established:

    • If the weather is dry then provide water as needed
    • Weed as needed
    • Watch for deer and rodent damage. Young plants are less distasteful, more easily eaten. If needed, use a deer repellent or a barrier fence.

In future years: 

    • Your plants (in the right place) should not need supplemental watering unless there is a  serious drought
    • Larger and more established plants will be less tasty to herbivores and more resilient to a few nibbles.
      • But different deer communities have different preferences. If your deer seem to like some of your “deer resistant” plants like some people pop jalapeno peppers, then you have a choice of maintaining your deer barrier or giving up on those plants.
    • Closely spaced plants should grow to be pressing tightly against each other, choking out  weeds
    • Feel free to edit plants that aren’t doing what you want 
    • Supplement with new plants, both younger stock (“perennial” is not forever) and diverse new species
    • Don’t be too tidy! Leave seed heads for birds , stems for nesting native bees (shortened is ok), and leaf litter for overwintering insects.

Doing Less turns a “Perfect Lawn” into a Good Lawn

The  20th century short and uniform “perfect” lawn provides no habitat or food for wildlife and is not much better than pavement for slowing stormwater runoff to reduce flooding.  Expanses of “perfect” lawns also consume large quantities of pesticides and fertilizers and huge quantities of irrigation water– American lawns are the nation’s largest irrigated crop.   

Less investment in Lawn creates more Value:

    • Less lawn provides more environmental and infrastructure services – Incrementally convert unneeded lawn area to gardens, meadows, and woodlot. 
      • Each square foot of converted lawn adds onto to Doug Tallamy’s HOMEGROWN NATIONAL PARK  and builds out the Pollinator Pathway
      • Trees, shrubs, gardens and meadows intercept and infiltrate much more storm water than lawn, reducing the risk of flooding
    • Leaving “weeds” in a lawn provides valuable wildlife services
      • Violets, white clover, dandelions, and other “weeds” provide important nectar and host plant services
        • Violets are the only host plant for sixteen species of Fritillary Butterflies!
    • DON’T USE LAWN CHEMICALS (except maybe for targeted spot treatments)
      • Lawn fertilizers are soluble, polluting our watersheds. 
      • Lawn herbicides kill the beneficial plants we need, like violets
      • Insecticides are not selective! They kill many beneficial insects for each single target insect.
        • Regular Mosquito Yard Treatments are particularly harmful
          • They CANNOT create a barrier to prevent adult mosquitos coming from adjacent yards
          • They DO kill all the beneficial insects that they contact– including the butterflies and bees. (Whether they use synthetic or organic pesticides)
          • MOSQUITO SPRAYING | beecatur
    • Mow your lawn at 3” or higher 
      • This supports deeper roots, requires less watering, and retains more storm water
    • Postpone your first mow in the spring to allow over-wintered pollinators to get off to a good start

To explore other native plants for your garden

    • Jersey Friendly Yards – This user-friendly site helps you quickly find and learn about native plants that fit your local garden.
    • Native Plant Society of NJ – The many NPSNJ members are knowledgeable, enthusiastic, and love to share. Their website has excellent NJ information and offers a host of great webinars.
    • Lady Bird Johnson Wildflower Center – This is a go-to resource for accessible information on over 25000 native plants.

Make Way for Pollinators Plant Sale Newsletter Archive

      • Edition 1, January 2022 > HERE
      • Edition 2, March 2022 > HERE
      • Edition 3, April 2022 > HERE
      • Edition 4, August 2022 > HERE
      • Edition 5, January 2023 > HERE
      • Edition 6, February 2023 > HERE

How do I learn about plant-insect interactions?

Heather Holm has written a number of outstanding books, does frequent webinars, and has a variety of free charts and posters on her website.

This is a quick reference table Heather authored with Prairie Moon Nursery:

This is a great free book from Cornell:


Ohio Pollinator Guides

Insect resources from Eric R. Eaton, author of Insectpedia (Princeton University Press, 2022), and Wasps: The Astonishing Diversity of a Misunderstood Insect (Princeton University Press, 2021). Eric provided these guides and although are created for Ohio, we have very many of the same species according to Eric. They are full of helpful information and close up photos to allow you to begin to identify the pollinators you begin to see around your yards.

Frequently Asked Questions

Lawn management uses pesticides, herbicides and fertilizers that migrate into our groundwater, streams and rivers. Mowed lawns have shallow roots and often require irrigation, increasing demand on our water supply. In contrast your native plant garden requires no pesticides, herbicides or fertilizer and once the roots are established also requires no watering.

Shallow-rooted lawns are also not a lot better than impervious cover because their limited ability to help the soil absorb rainfall allows heavy rainfall to quickly become stormwater runoff. In contrast, deeply rooted native plant gardens and woodlots with ground plantings and leaf litter blankets make the ground dramatically more permeable– materially reducing stormwater runoff and filtering pollutants. This is why native herbaceous and woody plants are used in rain gardens. Your native plant garden provides rain-garden-like permeability in an area that used to be almost impermeable lawn!

Nurseries grow plants in trays of plugs that are designed to develop a strong, healthy and untangled root system.

Landscape plugs are extra large plugs that provide mature plants robust enough to plant directly into the landscape, an efficient alternative to container plants. This size plug is 2” x 2” across and 5” deep. The roots are substantial.

Native perennials invest in developing robust roots before investing in rich foliage and flowers. The root systems in landscape plugs enable many species to be impressive the first season after planting. There are some species that may still take another year to impress, but it is still a much shorter timeframe than other similar cost approaches.

Landscape plugs are particularly appropriate for native plants, which grow best in native soils and not in enriched soils. The landscape plug’s strong roots reach immediately into the native soils. North Creek Landscape Plugs™* vs. Larger Containers:

  • Reduced media volume results in quicker establishment and acclimation to native soils*

  • Landscape Plug™ tray design and growing practices result in greater root mass*

  • Root channels, tapered cells and drainage holes direct roots to one point for air pruning, resulting in dramatically reduced root circling*

*From the North Creek Landscape Plug Manual

A rain garden is a native-landscaped artificial retention basin to retain and infiltrate stormwater runoff from rooftops, paved areas, and lawns. Rain gardens are “green stormwater infrastructure” to to intercept, filter, and infiltrate stormwater just like the natural stormwater infrastructure of forests and meadows that preceded development. NJ state law now mandates that all major developments implement green stormwater infrastructure, and many municipalities have extended this to also encompass minor developments.

Increased green stormwater infrastructure is very important in all developed areas because extreme precipitation events have become dangerously more common (over 70% more frequent over the last 50 years) and this alarming trend is forecasted to continue, particularly in North Jersey. NJ rainfall studies summary

If you are changing your landscaping, please consider if you might squeeze in a rain garden! Rain Garden Manual of New Jersey Rain Garden basins are typically 4-8 inches deep, on a permeable soil with the bottom of the basin one foot or more above the water table (so that the water can infiltrate). Place it 10 feet or more from your basement so that the infiltration does not end up there.

Rain gardens should be tightly planted like any other native garden. Plants in the bottom need to tolerate standing water for perhaps hours in really rainy weather and survive drier conditions in between. Moist-to-wet soil characteristic is generally OK. Plants on the sloped edges need to suit drier conditions than those on the bottom, eg moist or moist-to-dry. Deeply rooted wildflowers, grasses, shrubs and trees are important because it is the root channels that infiltrate the water. The Rain Garden Expansion kit plants were selected to supplement the Core Sun Kit plants to provide 10 great species for a rain garden. You can supplement this with shrubs (eg buttonbush, clethra and elderberry) and trees (eg Swamp White Oak and Pin Oak) if appropriate.

If you can’t do a rain garden, just convert more lawn! During a heavy rainfall, your native garden or woodlot can provide all the filtering and infiltration services of a rain garden, it just lacks the shallow basin that retains water when the rainfall lightens up.

Full Sun is sun for at least 6 hours per day.
Part Sun is sun for 4-6 hours, mostly in the PM (from the west)
Part Shade is sun for 4-6 hours, mostly in AM (from the east)
Shade is sun for less than 4 hours per day.
The sun is out for several more hours in the summer than the winter and the sun’s course across your yard is quite different from early spring through fall.
If you are interested, the website www.suncalc.org and its android mobile app can help you map the course of the sun at any site and day.
The seasonally shifting shadows from buildings and trees can be different than what we estimated in a different season. If your plants end up in a place that has less or more sun than you intended, they may need to be moved. This is a common gardener experience 😊.

Generally, wet-moist-dry refers to the average moisture level across the seasons.

  • On most flat areas, North Jersey soils are  “moist” because of our soils and our generous annual rainfall.  They are wet during the rainy season and dry during dry spells but they are moist in between. If you have a sump pump, you may notice that it is most active seasonally.
  • On flat areas near water and wetlands (where the water table is high) soils are “wet” and stay that way year-round. If you have a sump pump you probably notice it is pretty active year-round.
  • On slopes and hilltops soils are drier (unless there is a seep or spring), most dry where there is south or west sun. You may not even need a sump pump. 

But there are always local exceptions because of variation:

  • Sunny areas are drier.
  • Areas with lots of organic matter are moister.
  • A small rise will be drier than slightly lower adjacent areas.
  • Rocky and thin soils tend to be drier.
  • Tree roots (which can extend out up to 2 times the distance of the branches) will create areas that are drier. 
  • Poor draining compacted or clay soils take longer to infiltrate water, keeping the soil wet for longer periods.

The typical soils of North Jersey yards are silty loams and silty-clay loams with a slightly acid to neutral pH. Alkaline soils only exist near outcroppings of dolomite and limestone, which does exist in small parts of the NJ Highlands.

You can do a quick soil texture determination by squeezing a handful of wet soil in your fist. The higher the fraction of clay, the more ribbon-like the soil will ooze out from between your fingers. A silty-loam will not ooze much at all. A sandy soil will just clump up and of course feels gritty.

You can also get a formal soil test Soil Testing Laboratory (Rutgers NJAES), but note their recommendations for soil amendments do not apply for native plants, they apply for agricultural crops and formal lawns and non-native ornamental gardens. 

The Rutgers Master Gardener Helpline for your county has great people to help you out.

The following plants will grow well in sunny dry conditions (but may still require periodic watering until their roots are established):

  • Purple Coneflower
  • Anise Hyssop
  • Beardtongue Foxglove
  • Showy Goldenrod
  • Switch Grass
  • Wild Bergamot
  • Obedient Plant
  • Culver’s Root
  • Rattlesnake Master
  • Butterfly Weed
  • Seaside Goldenrod
  • Blue Wood Aster

The 5 Shade Kit species were selected for such locations:

Foamflower, blue lobelia, wreath goldenrod, blue wood aster and christmas fern.

Few plants are happy in heavy shade, but amongst these 5 species foam flower and christmas fern are the most shade tolerant.

Beyond these five: Heart-leaved golden alexander, pennsylvania sedge, golden ragwort and columbine can do well in part shade under trees.

Heart-leaved golden alexander, pennsylvania sedge, and golden ragwort can serve as ground covers in sun to part shade. Golden ragwort is semi-evergreen.

Foamflower can serve as a ground cover in part shade to shade.

Hell strips between the sidewalk and road are generally sunny and dry, but also subject to road salt. Not all plants are salt tolerant.
These are the five sunny and dry plants we offer that also have salt tolerance:
  • Beardtongue Foxglove
  • Butterfly Weed
  • Purple Coneflower
  • Seaside Goldenrod
  • Switch Grass
These are two other sunny plants we offer that have salt tolerance, but need moist soil:
  • New York Aster
  • Blazing Star
Source: North Creek Nurseries list of salt-tolerant native plants.

These photos show a lawn area in Morristown converted to a pollinator garden using landscape plugs in 2020. These photos are showing the garden’s rate of growth from June to September, although in different views. The plugs were planted in late June because the bed was not ready earlier.

Plugs just planted…

June 28, 2020                              July 17, 2020                                September 21, 2020

      

None of our suppliers use neonicotinoids, which are systemic pesticides whose residuals can remain toxic to pollinators for months and sometimes years.

We are only offering plants that are considered “deer resistant”. Unfortunately no plants are “deer proof”– deer in different areas develop different tastes, and a “deer resistant” plant in one town may be a “deer snack” in another.

Plants seem to be most vulnerable in the spring when they are small and also when new fauns start to learn to feed themselves.

Our recommendation is to monitor your young plants. If you see nibbling or if deer have been a problem, use deer repellent in spring and early summer to train the deer to try someplace else.

If your neighborhood is crowded with deer, you may need to use permanent deer exclosure. You can cage single or groups of plants or put up a deer fence. For small areas a 5 foot fence may be enough, but for large areas you will need a 7 or 8 foot fence. Lightweight plastic deer fencing is low cost and easy to put up and from a distance seems almost invisible between the posts. Heavyweight plastic, wood, or metal deer fences are more rugged, but also more expensive and noticeable.

All of these landscape plugs are sourced from wholesale native plant nurseries in New Jersey or eastern Pennsylvania. They are “ecotypes” suitable for our area.

The primary wholesale native plant nurseries for our Spring 2022 sale are New Moon Nursery in Woodstock, NJ and North Creek Nurseries in Landenberg, PA . One species is sourced from Kind Earth Growers in Ottsville, Pa. We are grateful for their commitment to local ecotype native plants.

These plants are all “straight species”, not purposefully bred or selected cultivars or nativars (native plant cultivars).

Straight species maintain the full biodiversity and natural variation of the species, which is important for species resilience.

Cultivars and nativars are each “clones” of a plant selected for specific characteristics that are attractive to a gardener.

Native plant cultivars that maintain the leaf color and flower structure generally provide environmental services as well as straight species, so some people might chose to use them in their garden.

Research shows that cultivars that change the leaf color (eg from green to red or purple) or the flower form or flower color (eg from single petals to double petals or purple petals to white, green, or red petals) DO NOT support native insects as well as straight species. For more information read  Native, or Not So Much?