Leave the Leaves? Not Always.

A Reality Check on Raking Vs. Leaving Leafs

When Momma fell, she was trying to right a Mexican sunflower that had slowly laid over on the ground. Those tall old plants do that this time of year. But they don't care; the leaves and buds turn up toward the sun. Hundreds of pumpkin daisies opened, facing up, from the prostrate bush. I tried to tell her to leave it lying there; it's prettier lying over than it was standing. But Momma wanted to tidy things up, and now she’s lying on the ground over there by the sunflowers.

In Momma's garden, we rarely rake. If we try, she seems to sense when leaf nutrients are being removed. She could be inside baking biscuits, but she’ll yell through the screen porch, "Wait! Don't take that load of leaves away! That's good for the garden; put it over under the fig bushes!" she'd say.

This wisdom is now reduced to memes and shared on social media with slogans like "Leave Your Leaves!"

Like all slogans and generalizations, it’s good advice—except when it isn’t. When promoted as dogma or the only or the best way, we have a problem.

Mexican sunflowers grow from seed to 12-foot-tall plants each summer. The plants usually fall over in October, allowing us to pick them up without a ladder. 

Sometimes, it's not safe to leave leaves where they fall. Here's why:

• Leaves against a structure can be a fire hazard.

• They can create a termite connection between ground and wood

• Around all barns and sheds, an annual winter cleanup is necessary

In heavily wooded neighborhoods, there are too many leaves to leave. While we live on the farm with Momma, Tom and I have a little city escape, too. We dedicate about 20% of that lot to tree and shrub beds where extra leaves accumulate. Still, we take some leaves away. It's a space vs decomposition issue.

Plant collectors have problems with leaving the leaves, too. Not every plant can tolerate a thick fall leaf layer. Lots of my special plants don't want to be covered by rotting leaves all winter:

• Cactus, Agave, Mums, Sedums, Georgia savory, Grasses (turf included), and winter foliage bulbs like Red Spider Lily dislike winter buildup.

If I smother those beds with leaves, I’d lose many of my bulbs; their winter leaves need sun from December through April.

Hard Leaves That Don’t Rot

In the South, where live oaks and magnolias prevail, those big waxy leaves make ankle-deep, fun-to-kick-through layers like confetti at a parade. They kill anything under them.

Live oak, water oak, magnolia, loquat, tea olive, and holly trees have slow-to-decompose leaves. Forestry folks call these "recalcitrant leaves" – which sounds very scientific. That word is more often used to describe hardheaded children and puppies. And it’s probably been directed at me, too.

Hard, evergreen leaves contain lots of cellulose, lignin, and tannins – all things that decompose very slowly. They also tend to be low in moisture and nitrogen – both needed for decomposition. In the forest, fungal activity and enzymes eventually break the leaves down. But that process can take years.

There are some cool studies of additives that innoculate and speed up leaf breakdown. But for now, if you want to keep and recycle your recalcitrant leaves:

1. Mow them with a mulch mower to speed up the process

2. Bag them up in plastic trash bags. Include a little dirt with some of that white fungus and a squirt of water, then tie the top.

3. Put them aside, and in a few months, you'll have some really heavy bags of nice compost.

This video shows the fungus and the unhealthy depth of recalcitrant leaf build-up on a city lot.

Let Dead Perennial Stems Stay Through Winter

In many cases, I treat flower stems and debris the same way I treat leaves. In some spots, I tolerate the mess and let them stand. Insects and birds need them. In spring, I remove what doesn’t decompose.

But sometimes, the winter mess is too much. And for some people, it’s hard to resist tidying up. Momma, who doesn’t mind the mess, does like garden exercise— so if she wants to spend the last sunny warm days of fall tidying up, I’m all for it.

Momma was outside raking and strapping up a Mexican sunflower to exercise and enjoy a beautiful day in her garden. Her commitment and drive fill my heart with joy. Did she take away some caterpillar habitat? Sure. She broke the rule of leaving the leaves.

I better help her get up. Luckily, because we mostly leave the leaves and mostly leave the dying perennials in her garden, the ground is super soft over where she fell.

When Momma lost her balance, she landed on nice cushiony soil. She called over to me for help but said “No hurry. I’m fine and I can reach some sunflowers from here.”

She kept right on snipping at her sunflowers while lying on the ground. That's the real victory—a garden that's not just beautiful but, like Momma and rules, flexible and adaptable, too.

Momma is our main perennial propagator. She has the deer-resistant, November-flowering golden perennial marigold ready now. Check out her plants HERE.