In my last column, I made my annual plea, channeling my inner Lorax, for readers to consider prioritizing wildlife during their backyard winter preparation. The simplified request is to “leave the leaves” as this provides critical wintering habitat for wildlife, including those at risk, like bumblebees, or adored, like woolly bear caterpillars (aka Isabella tiger moths). We received a bunch of follow-up questions, particularly asking what happens come spring. So while this article will include advice you’ll want in five months, I think it is important to answer those questions now in case anyone is on the fence about leaving those leaves under the fence.

Let’s start by fast-forwarding to the spring, specifically the real spring, when tree buds are emerging and red-winged blackbirds are filling in wetlands. The ideal timing for waiting to clean up the leaves is when we see a steady string of warm days, preferably over 50 degrees. This is when all those animals that have used the leaves for shelter will become active again, and you’ll likely be hearing and seeing them around this time. Wood frogs and spring peepers will begin vocalizing as they look for mates, and our earliest butterflies will be flitting about. Look for mourning cloaks, which overwinter as adults, as they are now ready to take flight with the warmth. One easy way to think about it: when it’s warm enough that you’ll want to be outside doing yard work, it’s probably fine to remove leaves or leaf cover.

This is a natural segue to mention the increasingly popular concept of “No Mow May” which is another great undertaking for improving backyard habitat. Every year is going to be different, which is why I recommend waiting for consistently warm days rather than adopting the “No Mow May” tactic. This past spring was especially warm, with the NOAA Climate Review for May 2024 stating that temperatures ranged from 2.5 to 4.5 degrees “above the 30-year 1991-2020 normals.” I mention this because by the third week of May, any wildlife that was overwintering in the leaves was certainly up and at ’em, if not already maturing through their next life cycles. The area of my yard that I do keep as grass needed to be mowed because the grass was growing taller than my push mower could handle, which gets us to the best answer here: do the best you can.

Often, when we make suggestions like “leave the leaves” or do “No Mow May” there is pushback: people love their non-native flowers, they like the look of a grass lawn, etc. It is important to acknowledge here that this isn’t an all-or-nothing kind of thing; do what you can, as every little bit helps.

I like using my own yard as an example. I’ve put a lot of effort into planting natives and naturalizing the section of my yard opposite our driveway from the house. The red osier dogwood twigs look beautiful with the sugar maple leaves now carpeting the ground, while the yard in front of my house is fairly bare. This area I keep as mowed grass, simply because of our culturally established expectations around “curb appeal,” and so I mulched most of the fallen leaves on that small section. Our backyard, which will mostly be mowed grass all summer, except for the edges we don’t use, is left with a cover of leaves that I won’t rake until those warm (probably late May) days. Most of those will go into a compost bin or under trees where I don’t have grass.

It is hard to give an answer for every backyard out there, but I hope you can find even little changes that to make. We are experiencing a biological crisis right now, and if you can influence the management of a backyard or local green space, you have an opportunity to make a difference for wildlife. Increasing the numbers of native plants and amount of habitats on the landscape is critical to maintaining that low tier on the food chain and supporting the wildlife that we all need to survive.

Have you got a nature or wildlife question of your own? It doesn’t have to be about birds! Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 7 to 9 am, at Maine Audubon’s Gilsland Farm Audubon Sanctuary in Falmouth.