long . lines and ripples

Spring Damage

Late May is the time in Chicago when a resident can say, with confidence, that the seasons are changing, and that Chicago will in fact look green again. Around here frost in April and May will beat back the initial spring; it will wilt early flowers with snow, damage buds, and remind us that our safest color–the one that we have all become quite comfortable with for the last six or seven months–is a widespread grey. But by now, the most adventurous early weeds have gotten big, and even the most cautious plants are starting to show enough green to indicate which way things are going.

A healthy green state is precarious, always sandwiched between other shades and states of health. To get there, a plant may pass through colors that resemble fall more than spring.

Take the maple tree (I believe a silver maple) outside of my apartment. The leaves first emerge yellow, the same color they will be in fall when they die and fall of the twig. I have not confirmed it with an authoritative source, but I suspect this initial yellow is related to the same lack of chlorophyll that renders them no longer useful to the tree–and turns them a brilliant yellow– in fall.

At points in mid-spring this can give the entire tree a yellow tint, like a preview of fall color in early spring.

This picture, taken in Chicago in late May, shows the overall yellow tinge of a tree (center of picture) still in the process of leafing out for the year.

Once the leaves finish their yellow phase, they will turn a pale shade of green before reaching their final, healthy summertime color.

Close up of the newest leaves on the twig of a silver maple (Acer saccharinum). The more mature leaves toward the bottom are a deeper shade of green, while the newly emergent leaves on top are yellow-colored.

It is also at this point, when the leaves are closer to their full summer size, that fungus and diseases begin show their effect on trees. The leaf, the visible marker of new life on the tree, becomes the palette for rot and decay.

Yellowish new leaves on one twig alongside mature leaves afflicted by a fungus or virus.

And the seeds of the silver maple, which emerge in springtime along with the leaf buds, will turn shades of yellow, orange and finally brown before becoming brittle and falling off the branch. On many plants, a seed is ripe when it is brown or even black, shortly before it rots.

Silver maple seedpods
Seed pods in May on a silver maple, soon to fall off

The way back to a healthy green goes through the colors of decay contained in the other seasons.

When the spring leaf-out is viewed from above, from an airplane or satellite camera, it is obvious that spring is an immense consumption of resources, an effort undertaken by trillions of organisms, each with its own process for restarting growth in the spring.

Washington Park in winter
Washington park in summer
Washington Park, Chicago in winter (top) and summer (bottom). Source: USGS Earth Explorer

Not all living things that try to continue the seasonal cycles will make it. Spring time is a trial that can both damage and exhaust.1 Plants that reemerge from the winter contain reminders of other, less healthy, points in the year, and the effort to regain health also entails the possibility of sliding back.

  1. The human body has to adjust to spring, too; as it gets hot again and the sun shines with an intensity that I have not felt for a while, my skin sustains more damage than I am used to. The repairs leave me more tired than normal.[]