How to Design a Concrete ‘Green Man’

Sometimes, ideas can from the oddest inspiration and truly have their own plan! Possibly this may be one of those projects that wanted to challenge me. Read along if you want to see how even the best plan can be unpredictable and still have a chance. This story is about how to design a Concrete ‘Green Man’…

So what really is a ‘Green Man’?

The green man legend may not be on trend but following the unicorns and rainbows gets dull… Since I have a rustic style that embraces natural elements making a ‘Green Man’ seemed like a logical choice. He represents the wild, untamed Spirit of Nature so it’s perfect as a new sculpture in my garden that will seem like it just naturally grew there.

In the Northern Hemisphere, His power cycle tends to be when the green growth of the world is at its zenith, from the spring equinox to the summer solstice, peaking at Beltaine or May Day. Because he returns each spring with new growth, He is associated with renewal, resurrection, and rebirth. (

My connection to nature and the elements; leaves and faces, makes this a perfect design combination! I am excited (as I love to play with concrete)! ‘Getting rid of any extra evil spirits is a bonus!

How to Make the Green Man elements:

I had sculpted a large face ‘mask’ that I used to make my garden face sculptures. The silicone concrete mold I made has been in the shed for 6 years (freezing winters) and is still in perfect condition. I am quite impressed how this home-made mold material works and lasts. I have also been using leaves to cast concrete for more years than I can remember. That makes this design combination just perfect, or so I thought…

As an illustrator I like to sketch out designs (using Procreate on an ipad pro). I can use photo references and ‘build’ something to look at before I actually get my hands dirty.

The ‘Green Man’ has leaves around his face with no specific rules on placement. The leaves will camouflage any mistakes so it seems like a perfect way to design. If you do not have a face mold like I do you can fashion one from Halloween masks as well. You can also just sculpt one from clay and make a silicone mold from it. The Green Man design has often been seen carved into architecture, or you can design it to hang on a wall/fence like a plaque.

There are many ways to make molds, homemade silicone, latex or even commercial silicone like Oggoo (as I used to make the relief casting molds.)

Making the Face:

Here’s the plan; make a large face ‘mask’ and and then make leaves to attach as I want afterward. My large silicone mold does need some stabilization as it is flexible. I filled the kiddo’s old wagon with damp sand and used it to nestle the mold into. You could also use some soft soil if you like.

Depending which concrete mix you use will determine how thick you need to fill it and for how long to cure. Since my favourite Rapidset Cementall was out of stock for weeks here I resorted to Quikrete Fastset AllCrete. I like to use the very quick curing mixes as they are also very strong. Read the specs on the bag about whether there is aggregate (gravel) in the mix (don’t want) and how thin/thick it should be used. I have used this mix before and it held well for the Giant leaf orb. (check out the video to see the mask being made) A regular portland cement & sand mix can work if it is applied thick enough.

Blend the Quikrete Fastset AllCrete mix with cool water to a consistency like peanut butter. It will start to get thicker right away so start a bit thinner. The goal is to have it pliable enough to hold shape in the mold and create a thickness of about 1/2″ – 1″ for the shape of the mask. I like to have the ragged edge and non-symmetry.

After a few hours I was able to take this out of the mold and hydrate to help make a strong cure.

Casting the Leaves:

Adorning the face will be a variety of leaves. Since I wanted to be able to decide on design later it seemed that making individual leaves is better than molding on the face. To have some interesting form I made some mounds and indentations in the wet sand (to hold the shape) and laid the rhubarb and savoy cabbage leaves vein-side up in/on them.

The sand mounds will make cup shape leaves and the valleys will make mounded shapes. Make sure to place the leaves with the veins upward. (more details casting from leaves)

There’s a concrete problem:

I have been working with concrete for many years and have never had this happen. The concrete developed Efflorescence quite quickly during the cure. This means that there are some soluble salts that have migrated to the surface and since the water evaporates it leaves the salts behind. After reading, it is not a problem since it can easily be washed off, but somehow I think something else is happening.

The last time I used this mix it did not happen. I am also skeptical since it has been a challenge getting some concrete lately. Perusing the stores I did not see new inventory since last year. I suspected that the stack was old concrete from last spring/summer. I know that concrete gets ‘old’ but it’s almost impossible to have someone give you the date as it is not listed on the bag. Quikrete said it would be in the barcode but I have not gotten response from them after being passed from one sales person to another. I wish there was a good system to determine how to know I am getting new concrete from a manufacturer so I can plan it’s use.

Weather and temperatures can affect how concrete cures but it was perfect mildly warm weather; perfect concrete-working weather. ‘So why is this happening?!

Why does the concrete Crack?

After closer inspection I am starting to see cracks develop too. Am I being impatient to unmold too quickly? The concrete says it sets in 15 minutes and I de-molded when it seemed hard enough. Cracks would develop later which completely baffled me (and angered me).

As this concrete casting of the face cured further it just cracked apart by itself – imagine that! I had put fibreglass mesh through the form but not across. I am stubborn and do not trash things too hastily; there is always a way I believe…

Casting More leaves:

Maybe I should have waited longer so I cast more leaves. I believe as concrete ages it can still perform but not to it’s full ability; it gets weaker and that is why we are not given a ‘best-before date’. I will definitely be talking to the store as it’s vital when you invest time for something that ends up breaking. I’d really like some answers…

I cast more leaves and waited longer, just to be sure. You can use older concrete but the finished specs will be affected. It’s all an experiment for me for future know-how. That is how you learn in the best way.

Casting More leaves:

To test the mix more I cast many more leaves and let them cure quite long. Just like food ‘best before dates’ the mix expires slowly. It will still cure to an extent, but possibly not to the maximum ability. Since I was all set to create I just kept going. The real test will be after a long cure; to see how strong they actually are. I may then also be informing the store.

Assembling the ‘Green Man’

I’m looking forward for the rain to stop, and the air quality to improve (sadly many fires are burning in Canada) so I can get outside to ‘create’ a design that I am happy with. Stay tuned as this project ‘hopefully’ comes together – fingers crossed! Let me know your concrete problems and wish me luck. (see also my concrete issues post) Perhaps this fellow will ward off the ‘bad concrete’ spirits!

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    1. I have a preference to keep them as natural as possible, as I believe that a coat of paint will eventually fail. Concrete (most basic ones) breathe so a thick coat of paint will peel or chip. Small accent or thin washes work well as if the fail it won’t be noticeable. See this post for ideas of finishes for other uses. ‘If’ I add some colour washes I use acrylic. Stay tined for the post of finishing this fellow…

  1. I enjoy your concert it’s beautiful especially the leaf man I made the head and daughter took it also. birdbath problem with the paint staying on I would love to be able to stand next to you and work I learn faster that way

  2. Hi Barb, I am Zan. Thank you so much for the time and energy you put in to your site! I found you while searching for cement tutorials. As an artist that is my passion this year. Lol. I am going to try some of the other things you have online, your work is beautiful! I am from the Oregon coast, I would choose you for a friend as your generous sharing spirit is what I feel a REAL artist has. I hope you get 10 x back what you share here Zan DANFORTH,Seaside Oregon