Many gardeners typically associate the idea of “native plants” with colorful and vibrant wildflowers. But when you’re looking to make a big impact, it’s native trees that give you the most bang for your buck, in multiple ways.
Trees perform hugely beneficial functions for our own properties by providing shade. This helps with cooling in the summer and protecting your home from frigid winds in the winter. There’s a significant financial benefit to these reductions in both air conditioning and heating costs, and trees are known to significantly add to your property value (often cited as between 3 and 15 percent). They also help reduce your carbon footprint, since trees are great at storing carbon dioxide as they mature.
The ecosystem value of trees also reaches comparably high levels. Native trees are often “keystone species” that fuel diverse food webs in ways that no other garden plant can. Their leaves sustain hundreds of caterpillar and moth species which in turn become food for birds, in addition to providing cover, shelter and nesting sites.
From a garden design perspective, trees and shrubs can provide a sense of enclosure or a central focal point; screen an unwanted view or exposure; and give structure to distinct zones of the garden for particular functions and activities.
Native trees become even more powerful when combined with shrubs, which are ecological powerhouses in their own right and many bring the additional benefit of colorful flowers.
Incorporating shrubs into your native garden is a great idea because although many of the larger native trees are still mainstays in typical urban and suburban yards, these shrubs are much less common and many have practically disappeared from our human-created landscapes.
To benefit from and enjoy both trees and shrubs together, a great way to garden to help maintain vital wildlife habitat is to replicate the different layers that are present in a natural landscape.
A “Layered Landscape” starts with the tallest layer, the canopy trees. Below those are the understory trees, followed by the shrub layer, then flowering herbaceous plants below that (Read more in The Living Landscape by Rich Darke and Doug Tallamy).
This type of landscape “offers beauty on many levels, provides outdoor rooms and turf areas for children and pets, incorporates fragrance and edible plants, and provides cover, shelter, and sustenance for wildlife.”
Won’t These Trees Shade My Flower Gardens?
But there is some potential conflict between packing your lot full of shade trees and attempting to plant a sunny native wildflower garden. So how can the two be reconciled for native plant enthusiasts?
For one, some gardeners aren’t aware of the diversity of beautiful flowers that do grow in the shade. Shade gardens are crucial for the future of the planet, as explained by one garden design book:
“The garden of the future will be a shade garden. There are many reasons: fiscal, historical, environmental—and for the sake of our health and of the planet’s. In many ways, this is an older notion of landscaping—it’s planting for generations to come. It won’t happen overnight, though. For one thing, it means planting trees.”
And you certainly don’t need to turn your whole yard into a forest and miss out on huge categories of plants in order to help the ecosystem. Depending on the dimensions of your yard, you can usually plant trees strategically so as to dedicate one or more areas to remain full sun. Then the rest of your yard “can focus on the bounty of beautiful part shade and shade flowers and groundcovers.”
It may be the best of both words to aim for a “natural woodland, with plenty of trees spaced far enough apart for the plants of the floor to grow,” an environment that “offers enclosure and endless fascination.”
And as it turns out, these “savanna” type of ecosystems were actually much more prevalent across the eastern and midwestern United States than the denser closed forests that we often associate the area with historically.
Some of the Best Native Trees and Shrubs to Plant
Planting trees and shrubs in your home garden can bring beauty, ecosystem benefits, and abundant food for wildlife and in some cases for us too.
Some deride native trees for being too “messy” while preferring supposedly superior “specimen” trees that are nonnative and in some cases even invasive. For one, the fears over the “mess” left by natives is often overblown. Any tree is going to drop leaves, and just look at the ground around a ginko or bradford pear tree after dropping its fruit.
Moreover, the nuts and other fruit of native trees are crucial sustenance to fuel the food web, and we can even get in on the snacking with some ecologically powerful trees like cherries, hickories, and walnuts.
The main decision you have to make is how much room you have in your garden space and whether a large to medium tree or a smaller understory tree or large shrub is more appropriate. Make sure to factor in the mature height and spread of each tree you are considering, because you don’t want it to outgrow its location and need to be cut down eventually. It’s mature trees specifically that have the most ecosystem power and carbon sequestration.
Some tree shaping of course can be achieved on an ongoing basis with pruning, but you want to avoid excessive trimming which will stress the tree and cause even more weakly-attached branches to sprout to replace the lost branches, starting a cycle of endless pruning while the tree suffers. For this reason it’s also crucial to avoid topping trees in an attempt to keep them smaller. For the most part, larger trees need to be allowed to grow to their full size, which in some cases can be 80-100 feet with a spread of up to 80 feet. If that’s not going to work in your yard, there are tons of great much smaller options too.
Fortunately, many of the most popular large and medium-sized trees already planted in the US are native and among the best choices. If you can fit their mature size, you can’t choose better than an oak: stately, symbolically meaningful, and stunning in all seasons and also the most beneficial tree genus for wildlife.
Another good choice is the maple: red and sugar are great choices in their native range with dazzling fall color but be sure to avoid the invasive Norway maple. Birches are another great option for ornamental value, including beautiful trunks, and wildlife benefit.
For those with smaller spaces or constraints like power lines, there are many great native choices that can fit the spot perfectly. With smaller trees, you often can plant them as a multitrunk tree or train them to grow with a single trunk. Many prized smaller nonnative trees are chosen and cultivated for their abundant and colorful flower blooms, but many native alternatives put on just as good of a show. For smaller trees in the range of 10-25 feet with beautiful flowers, try flowering dogwood, serviceberry, crabapple, or redbud.
Thinking specifically about ecosystem services and food webs, certain trees are “keystone” species that punch well above their weight in terms of supporting wildlife. As previously mentioned, in nearly all parts of the United States, oak (quercus) is the genus that hosts the most caterpillar species, in many places a staggering total near the 500 range.
In many regions, oaks are followed by willows (salix) which contain both trees and shrubs, birches (betula), and plums/cherries (prunus).
For coniferous trees (evergreens), pines (pinus) is normally one of the best choices. Maples (acer) are also high on the list.
For a keystone species list customized to your region, take a look at the National Wildlife Foundation website
As one author put it, “who wouldn’t want to find a spot in the summer garden that could be 10 to 20 degrees cooler than its counterpart in the sunny flower border?”
So whether you’re installing a whole landscape with canopy, understory and herbaceous layers, or just sneaking one smaller tree into an unused corner of the yard, going native is a great choice that will reward you and the planet significantly over time.
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