Mosses and lichens

The first greenery of spring: moss

I love moss! It’s spring’s first burst of color!

Photo: Andreas Neubauer 

Is Moss a Plant?

Yes, it’s a plant! Small (sometimes even very small), mosses, also known as bryophytes, have no real vascular system (you know, sap, maple water, roots, all that…).

Don’t look for the traditional bark, leaves and roots either: bryophytes absorb the water and nutrients they need from their entire surface. Their “roots”, known as rhizoids, serve primarily to anchor themselves to the substrate and are not designed to transport water from the soil to the plant.

Common Kettlewort (Blasia pusilla). Photo: Carole Beauchesne

This simple structure is the reason why moss is so quick to reawaken in spring… and why it can grow anywhere: on rock, concrete, trees, and so on.

How does moss survive without a water transport system? Quite simply, water circulates between the cells by capillary action. Like a sponge, as soon as part of the moss is wet, the water can spread to all the cells. It has to be said that with “sheets” only one cell layer thick, water is quickly absorbed… and therefore quickly lost too! Fortunately, mosses are well adapted to surviving drought, even better than vascular plants! The fact that they are grouped together in colonies also creates a microclimate that retains moisture: an isolated moss dries out much more quickly.

Ostrich-plume feathermoss (Ptilium crista-castrensis). Photo: Carole Beauchesne

As moss is a plant, it also takes advantage of the sun to photosynthesize. For bryophytes, spring is an incredible time: the trees are leafless, the sun is at its brightest and the ground is full of water from melting snow. No wonder moss looks particularly green in spring!

What Are Those Little Seeds Coming Out of the Moss?

First of all, they’re not seeds, but you guessed it, that’s the moss’s reproductive organ.

Tortella Mos (Tortula truncata) with sporophyte. Photo : Jean Faubert, Saint-Valérien-de-Rimouski, June 1, 2017.

How do mosses reproduce? Well, it’s quite simple. There’s no need for flowers, pollinators, fruit, seeds… In fact, all the moss needs to reproduce is a very small flooding of the colony. How little? Morning dew is enough!

Male plants carry their sperm with them (it’s not pollen) and flooding allows this sperm to travel to a female plant in the same talus. The female then develops a sporophyte: a small stem with a capsule at the end. This capsule contains unicellular spores (which are not seeds). These spores are dispersed by wind, passing animals or rain, enabling new plants to be produced.

Green-tufted stubble-moss (Weissia controversa) avec sporophyte. Photo : Jean Faubert

Cells also reproduce asexually, meaning that identical clones are formed. These arrive by budding (a new plant is created from the original) or when part of the moss is damaged or separated, the two parts regenerate, creating two completely identical individuals.

I know: if all plants did that, the gardener’s life would be easier!

Moss and the Gardener

Moss’s nutrient requirements are minimal, and since it doesn’t root, it’s a great ground cover for the laidback gardener who’s tired of watering his drama queens. You know the kind of plant I’m talking about: the one that’s always thirsty! Why not play a trick on it by offering it a living mulch?

Mulching is a laidback gardener’s best friend, as I’m sure you know if you’re a regular reader: Larry has told us about it once or twice (how about hundreds of times)! But here’s the thing: if you don’t like to maintain your mulch, if you don’t have enough dead leaves at home… try living mulch!

The advantage of moss is that if it has enough surface water and light, it protects the soil without stealing anything from your plant. Unlike a lawn, for example, which draws water and nutrients from the soil, moss will keep your soil moist, protect it from the wind, and grow and spread ALONE! And it looks good, too!

Inside?

When it comes to houseplants, it’s a little more ticklish. In a humid terrarium, on a bonsai that you water often, the moss is magnificent, but for a houseplant, I don’t recommend it.

Since most potted plants require watering only when the first few centimetres of soil are dry, either your moss will dry out, or your plant will get too much water, never dry out and its roots will eventually rot. As a general rule, no moss indoors. Photo: Ian

However, if it appears on its own and is happy in your regular plant watering routine, there’s no reason to remove it! In fact, it’s one of the few plants that really appreciates having its leaves sprayed (it doesn’t drink from the tub like your vascular plants).

Photo: Ahmed

I Once Cut Moss With an Axe…

I’m not going to leave you without an anecdote though! A long time ago, we had a lovely pond in my mother’s backyard. The kind of artificial pond with a little waterfall and beautiful rocks. Warning, archive photo:

The big challenge with this pond was the plants. Growing plants vertically, on rock, with only a handful of soil to anchor them… not exactly easy! (Especially since this was before the Laidback Gardener blog!)

One year, at the garden center, we were looking for a plant to put near the waterfall. Not an easy task: full sun, constant splashes of treated water and very little soil! No plant seemed suitable. Until I fell in love with a pretty moss.

It was strange, it was sold in a very deep pot, but it was indeed a moss. We asked the nice young lady if it was possible to remove the soil and keep only the moss part. She didn’t know what she was talking about, obviously, because she told us that no, you mustn’t remove the 8 or so inches of roots, otherwise the plant would die.

Our Experience

Well, we did as we pleased, we bought it, and once we got home, I cut the root ball… with an axe! We didn’t have much in the way of gardening tools, and the net of roots was really dense haha! We removed the 8 inches of soil and roots, separated the rootball into several pieces, and prayed before the carnage. Believe it or not: this is the plant that lived the best of all those in the pond, even growing and spreading out nicely. I can’t tell you how amazed I was!

Today, I realize that the clump of roots probably belonged to other plants that had taken root through the moss (like oxalis or clover), since moss, well, doesn’t have roots! I also realized that if the pot was so big, it must simply be that wide plastic pots don’t come in a “shallow” version!

Gardeners, now it’s your turn to tell us about your trials and errors with moss!

Audrey Martel is a biologist who graduated from the University of Montreal. After more than ten years in the field of scientific animation, notably for Parks Canada and the Granby Zoo, she joined Nature Conservancy of Canada to take up new challenges in scientific writing. She then moved into marketing and joined Leo Studio. Full of life and always up for a giggle, or the discovery of a new edible plant, she never abandoned her love for nature and writes articles for both Nature sauvage and the Laidback Gardener.

5 comments on “The first greenery of spring: moss

  1. I have been trying to cultivate moss in my walkways for years . It grows quite well but unfortunately so does plantain , grass and other undesireables which means every year I have to try to weed out those unwelcomed plants . It is almost impossible to do this without destroying the clumps of moss spreading throughout the walkway . So very sad as the moss itself is very esthetically pleasing. I am going to have to hit those weeds with some homemade weed killer which I am afraid will just undo all my moss efforts ……so disappointing !

  2. Moss does not proliferate within semiarid chaparral climates, such as within the Santa Clara Valley. However, it does proliferate just a few miles towards the coast, within the Santa Cruz Mountains. Tree stumps, boulders, and all sorts of exposed and porous items can resemble chia pets. Weirdly though, road crews remove it from concrete bridges, leaving the bare concrete exposed.

  3. Christine Lemieux

    This is a very timely article for me. I have always adored moss. This year I am going to start a moss garden. I will start small in a place that already has some moss and then add to it with rocks and other varieties. I am very excited!

  4. hashton071bb2a552

    Interesting & entertaining! Thank you!

  5. So fascinating! I like a bit of moss. A lot of gardeners grown upon it and point out the negatives that it shows that the ground is compacted or too damp. I agree it makes a very pretty mulch! I never knew about the female “egg stalks” though – they are on the surface of some of my indoor carnivorous plants’ compost.
    Thanks for the article!

Leave a Reply

Sign up for the Laidback Gardener blog and receive articles in your inbox every morning!