Trees for Fall Color

As daytime temperatures begin to cool and open windows at night let in refreshing breezes, you may need a light blanket on the bed. Day lengths are getting shorter as the planet travels around the sun at 67,000 miles per hour toward the winter solstice.

Trees begin preparing for winter by transferring chlorophyll from leaves into stems, showing us other colors present in the leaves. We enjoy this time of year with comfortable temperatures and the colorful change of seasons.

Young white oak and greybeard trees provide fall color and wildlife value in a Betton Hills front yard. Photo by Vanessa Crisler.

Compared to New England, North Florida fall color is more variable from year to year, but we do have several trees with dependable fall color. The trees mentioned here are all American natives which, in addition to great fall color, have value to wildlife throughout the year. Take oaks as an example. White oak and swamp chestnut oak leaves typically turn a pleasant shade of red. In spring and summer, caterpillars dine on their new succulent leaves. In the United States, ninety species of oaks are food for 534 species of caterpillars! Most of these caterpillars become high quality protein for baby birds and their parents. In autumn, acorns are food for insects, birds, and mammals.

During winter, we think of deciduous oaks or trees in general as devoid of insect life. However, many species of moths, particularly inchworms, overwinter as caterpillars camouflaged as twigs or hiding in bark crevices. They do absolutely nothing from November through February. Birds such as the ruby-crowned kinglet, golden-crowned kinglet, and blue-gray gnatcatcher survive the winter on these and other insects. Chickadees, which visit feeders all year, must have fifty percent of their winter diet as insects. Most species of native insects can only digest the leaves of native plants; let us look at native trees for our area that have dependable fall color.

Pignut and mockernut hickory, commonly seen growing along our canopy roads, are a beautiful yellow gold in fall. The dangerous looking, though harmless, hickory horned devil caterpillar eats hickory leaves and transforms into a stately regal moth.

Sweetgum, sometimes shunned because of its seed pods, is one of the best. Autumn leaves may be dark purple, red, or yellow. Luna moth caterpillars eat the leaves and American goldfinch and Carolina chickadees relish the seeds plucked from the prickly balls.

Red maple is like sweetgum in having a range of color – purple, red, orange, or yellow. The Florida sugar maple is always a fiery orange, while chalk maple is reliably yellow each year. A friend described a row of chalk maples in his yard as a line of candles glowing in autumn.

Bald cypress, a deciduous conifer, turns a wonderful rusty cinnamon color along our rivers or in your yard. Sassafras is usually red or yellow. It is also a larval food plant for the spicebush swallowtail. Black cherry, sporting red or orange leaves, is host to the caterpillars of cecropia moth, tiger swallowtail, and red-spotted purple, among others.

Two smaller trees with color are the blue beech and greybeard. Blue beech should be planted under taller trees and turns yellow gold. Plant greybeard, always a bright yellow in fall, in sun to light shade.

American beech leaves

American beech is unique in that it has stunning yellow-orange leaves in autumn, but the leaves do not fall off for winter. The leaves either turn dark rusty-brown or beige and stay on the tree until springtime. Young American beech trees are amazing standing in a deciduous forest in winter. They will be just as striking in your yard. It is long lived, growing to one hundred feet.

Keep a natural layer of leaves under the dripline of you trees. Do not rake up and dispose of fallen leaves. Caterpillars high in the canopy, when ready to change into a moth or butterfly, usually fall to the ground, hiding among leaves or in the top inches of soil where they pupate. Lawn grass under a tree canopy usually spells death for these creatures. Do not rake excessively deep layers of leaves or pine straw onto the root system of your trees. Interestingly, some caterpillars of butterflies and moths eat only the dead fallen leaves on the ground.

November through February is the best time to plant trees in our area, with December being ideal. Planting in December lets the roots get a head start growing before the next summer’s heat arrives. Plant at the correct depth with the root flare at the soil surface. Untangle, straighten out, or cut off any circling roots if the tree is pot-bound.

The absolute best way to plant a tree is to plant a seed or buy a small bare root seedling. This will allow the tree to develop a properly shaped root system as compared to a large pot grown plant, though young trees in three-gallon pots are usually fine too. Always check the roots. A healthy root system will support your tree in hurricanes and circling roots will not kill it 10 years into its life. Plant a beautiful, shade-giving, wildlife providing tree this winter!

Native Plant for Birds: Black Cherry

For my inaugural column featuring a native plant for birds, I have chosen the quite common black cherry (Prunus serotina) for two reasons. It is considered a keystone species, which means it has a disproportionately large effect on the abundance and diversity of other species, like insects, in an ecosystem. There are 247 species of caterpillars that feed on plants in the Prunus genus in my Tallahassee zip code. Entomologist, ecologist, and author Doug Tallamy considers black cherry and other native Prunus species as his #2 pick of ecological gold in the landscape with oaks rated #1. Visit National Wildlife Federation’s Plant Finder and type in your zip code to find out what native plants nurture the most caterpillars in your area.

You may wonder why I am writing about caterpillars when this article is supposed to be about birds. Let us look at one species – the Cecropia Moth. An individual female lays up to 300 eggs on its host plants of mainly black cherry, birch, or maple. Of those 300 caterpillars that hatch from these eggs, how many live to reproduce as a moth? Only two or three! What happens to all the others? They are consumed as high-quality protein by spiders, lizards, wasps and yes, birds – a complex food web with a native plant at its base. These caterpillars are produced when the leaves are young and tender, a time when birds are busy searching for insects, primarily caterpillars, to feed their young.

The second reason for choosing black cherry for this first issue is because it is a plant of my childhood. Growing up on the south shore of Long Island, I have fond memories associated with a grove of black cherries in our front yard. It is, indeed, a beautiful tree with grayish-black textured bark, and its long, slender densely packed white flower clusters that bear nectar and pollen for native bees and honeybees. The flowers are followed by abundant small dark purplish red to black fruit called drupes that are highly favored by birds from thrushes and woodpeckers to sparrows, tanagers, and bluebirds. And it even has nice fall color.

You can purchase a black cherry from a plant nursery but if you look around at the small seedlings that pop up in your yard, there is a good chance one may be black cherry. The copious amounts of fruit provide nourishment for birds and then birds do their part by dispersing the seeds, after they have been processed through their digestive tracts, to old fields, hedgerows, and urban and suburban yards. Black cherry will grow in sun or partial shade, 70 to 90 feet tall, in average to well-drained soil as far south as the Tampa/Orlando area. There are butterflies such as the Eastern Tiger Swallowtail and Red-spotted Purple that are associated with black cherry, but moth species produce a good many more caterpillars. One that comes to mind are tent caterpillars which are highly attractive to Yellow-billed Cuckoos.

What you plant in your yard matters. Your landscaping can be mere decoration, or it can be habitat for birds and other wildlife. It is up to you.

Native Vs. Nativar: Are native cultivars as beneficial to wildlife as true native species?

There is growing awareness about the value of preserving and restoring native plant habitats for the benefit of wildlife, especially our native pollinators. The increase in demand for native plants has led to the selection and breeding of native cultivars.

What is a native cultivar? A native cultivar or “nativar” is a cultivated variety of a native plant that has been selected, cross-bred, and/or hybridized by plant breeders seeking desirable characteristics – usually height, bloom color, bloom size, leaf color, and even disease or pest resistance.

Should you be using native plant cultivars? Are they as robust or as beneficial to wildlife as straight species natives? What exactly is a straight species?

There is an emerging debate over whether cultivars provide the same ecosystem services as the native species themselves. The research seems to be unclear when comparing the two because not all cultivars are created equal – some are better, some are the same, and some are worse at attracting pollinators; it really depends on the plant species and its cultivar.

So how do you know if a cultivar is good or bad? Unfortunately, it’s hard to tell and you must do your own research on what the plant was bred for.

Truly native Echinacea purpurea, is a key species for pollinators. Photo by Donna Legare

Double blooming flowers are a no-go as they prohibit pollinators from accessing the pollen or nectar. If they’ve been cultivated to change the flower color, they are almost certainly going to be less attractive than the straight species.

However, if their cultivated trait is just a larger flower or shorter growth habit, they may be OK. The bottom line is that when you can get your hands on the straight species, you’re always going to have the best possible plant for pollinators.

Renowned entomologist and native plant advocate Doug Tallamy says “the proliferation of cultivars demonstrates the extent to which the nursery trade is still stuck on the idea of plants as enhanced decoration rather than essential to wildlife. Always request true native plants because there is only a market for cultivars if we buy them.”

Another word of caution on native cultivars that is often overlooked is that they lack genetic variation. Their DNA is the result of artificial rather than natural selection and they present a vulnerability if a particular disease or pest becomes problematic. Without genetic diversity, there is less built-in resilience in our landscapes.

Once the genetic material from cultivars makes it into wild populations, there is no way to dispose of it. The new DNA affects the ability of wild native plants to survive and has ramifications for all the species that interact with the plant as well.

When native plants in our yards are straight species, their DNA can make a positive contribution to the survival of wild plant populations. The adaptive genetic diversity they share allows native species to persist, despite the rapidly changing conditions of the environment they are in.

Finding locally grown straight species is key to supporting local ecosystems. It’s like getting to know where your food comes from – learning where your plants come from increases transparency and the quality of information along the supply chain.