Introduction: Giant Mushrooms

Picture of Giant Mushrooms

I built these mushrooms originally for my annual Halloween haunted yard. They can be used in a variety of ways though - for Alice in Wonderland themes, Dr. Suess themes, weddings, theater, festivals, garden parties and more. These giant mushrooms range in size from 5ft tall to 10ft tall. They are made using wood, chicken wire, cheesecloth, 2-part spray foam, paint and spandex.

Step 1: Building the Stem

Picture of Building the Stem


3/4" plywood

(3) 2x4s

lag screws and washers

chicken wire

cheesecloth/ scrim

The top and bottom of the stems are made from 3/4" plywood. Using a jigsaw, I cut them into circles that are roughly 18" in diameter. The center of the stems are made with (3) 2x4s that will change in length depending on the desired height. At first, I had a 1x2 in the center but I don't think it was necessary at all. What IS necessary is using lag screws and washers to connect the 2x4s to the bases.

The lag screws are roughly 3/8" in diameter and 4-5 inches in length. The washers are very important and should match the diameter of the screws. We used a nut driver to tighten the screws. Make sure you pre-drill your holes.

Once the stem is secure, you then wrap them in 1-inch chicken wire from top to bottom using steel wire snips and a staple gun.

To prepare for foam, everything must have a skin for the foam to adhere to. This can be accomplished using cheesecloth or scrim. Cheesecloth can be rather expensive so I buy scrim in bulk by the yard from Online Fabric Store.

I simply adhere the scrim to the chicken wire using spray adhesive. It is important to work outside and use a face mask while spraying adhesive. Once finished, you can move onto the foam.

Step 2: Building the Cap

Picture of Building the Cap

The cap skeleton consists of the following:

3/4" Electrical Conduit

3/4" poly flex tubing (found in plumbing and pvc)

4x4 lumber cut to 1ft length.

1/2 " or 3/4" plywood

chicken wire

zip ties


The cap and stem are meant to be detachable to make for easy transport and storage. First create a stem and base for the cap itself. Cut an 18" circle out of the plywood and then cut the 4x4 into a 1 foot section. Use lag screws and a washer to attach the two. The tricky part was figuring out where to pre-drill holes for the conduit to go through. Using a 1" spade bit, drill your holes through the 4x4 for the conduit to pass through. Once you have your conduit through the holes in the center stem, you can start bending. Think of creating an umbrella shape with curves. The bends are subject to your own creative desires.

Once your conduit is bent and centered, wrap your pvc tubing around the perimeter egde. Pre-drill holes where it will attach to the conduit and then simply screw the conduit to the pvc tubing uisng screws, washers and nylon lock nuts.

Take your chicken wire (the wider the better) and lay it over top of the cap structure. Cut around edges and wrap excess under tubing. Attach with zip ties.

Attach scrim to chicken wire in the same manner as the stem.

Step 3: Foaming and Painting the Mushroom

Picture of Foaming and Painting the Mushroom

I used a closed cell spray foam system from Versi Foam. This is the System 50 kit. It comes in 2 tanks and it is magical. With shipping, this system costs a little under $800. To learn more about Versi Foam, visit

Follow instructions. Take all precautions. Be safe. This stuff is not to be messed with. Make sure you have all your safety gear including a suit, mask, goggles and gloves.

Once tanks are ready and you are protected, start spraying. The foam cures very quickly. I do 2 coats for added strength.

Once foam is completely cured, i then paint using a sprayer. Once paint is dry, attach cap to stem to prepare for the gills. This is a good time to add l.e.d. lighting or string lights. You can attach lighting to the underside of the chicken wire using zip ties.

Step 4: Creating the Gills

Picture of Creating the Gills

This is the most tedious part of the build as it involves lots of pleating, stapling, velcro and hot glue.

I start by buying 10 yards of 120" white nylon spandex from 10 yards should yield enough for a few mushrooms depending on their size.

In my original build I was stapling the spandex to the center cap and then hot gluing directly to the outer edge but I have since added Velcro so i can remove the spandex when not in use. You can buy Velcro by the roll in 1" strips. First i cut different lengths and stick to the outer top edge of the cap base. Then stick the strips to the entire perimeter of the outer edge.

Starting the pleat is tricky but think of using spandex in the form of triangles. I don't pre-cut these because if you make a mistake and the spandex doesn't reach far enough, you have wasted fabric. So I start by cutting a flat edge on the spandex, roughly 24" and then adhere that to the Velcro that was applied to the outer top edge of the cap base. I then pull the spandex out to the outer edge of the cap and start pinning to find my way through the pleat. This pleat will change as you start to permanently adhere but the pinning is necessary so you can get the correct drape.

Once done pinning, cut above the pin. Fold the rough cut part of the spandex over so it makes a clean edge and hot glue to the Velcro.

Once you have the first section of fabric done, move on to the next and so forth. I hot glue the fabric seams together and leave some open to get inside for light repair if needed.

Once finished with the fabric, I like to add fake moss for finishing and to hide any flaws where the foam doesn't meet the fabric.

Step 5: Illuminate and Enjoy

Picture of Illuminate and Enjoy

I up-light these with a variety of par l.e.d. light fixtures. The inside caps are lit with programmable l.e.d. string lights.

When using in a public setting, be sure to use tie lines for stability, especially when using outdoors.

Making of video:

[Play Video]


Maniacy (author)2015-02-02

Well, budget much? How much did you spend on those? 800$ on the foam alone? What the??? Marry me!!! I love every square inch of those mushrooms and their ridiculousness. Very trippy! Much festival. Wow!

R4veKitt3n (author)Maniacy2016-01-03

If you wanted to make something similar for a small scale event or party at a lower cost you could easily swap out some materials. The foam especially... you could just as easily use pillow stuffing from a craft store and spray paint it to get a similar effect. You can do regular Christmas lights vrs. LEDs Tulle instead of cheese cloth The idea of DIY is very easily altered. Will yours look super professional like these... probably not but they would be really great for a smple brthday party or haunted house :)

RaniaPeet (author)Maniacy2015-02-03

LOL much expensive, very ridiculous! That's me! If you build 4 mushrooms, it runs around $400 per shroom in materials. The tank system puts out enough to cover 4 mushrooms from 5' to 7' in size. The bigger they are or the less you make at a time, the more they cost. Definitely making more. My next build will be giant led flowers around the same scale.

cdavis46 (author)2015-09-24

Amazing work as always! I bow to your excellence!

RaniaPeet (author)cdavis462015-10-03

I bow right back!

giorgia14 (author)2015-09-23

A-M-A-Z-I-N-G.....!!!!!!!! Wish I could vote you 100 times for the Halloween contest..! >_<

RaniaPeet (author)giorgia142015-09-23

Thank youuuuuu! I wish you could vote 100 times too! hahah

PowellMade (author)2015-02-03

Well with all them in your yard there isn't mushroom for anyone not to have fun!! Nice project they look great!!

RaniaPeet (author)PowellMade2015-02-03

hahah thank you!

robolimbo (author)2015-02-01

Awesome 'shrooms! They would look great on a stage production!

RaniaPeet (author)robolimbo2015-02-02

Thanks so much! Yeah i haven't used them on stage yet, mostly at festivals for patrons to explore, play and relax in.

Rajat Cool (author)2015-02-01

Amazing,well done.

RaniaPeet (author)Rajat Cool2015-02-02

Thanks so much!

bettina-sisr (author)2015-01-31

WoW! I wished you lived by me, Halloween is my favorite holiday and you are a PRO! Thanks for this amazing Instructable

RaniaPeet (author)bettina-sisr2015-02-02

Thank you bettina-sisr! I love Halloween! Thanks for reading :)

WUVIE (author)2015-01-31

Wow, these are absolutely amazing! Kudos!

RaniaPeet (author)WUVIE2015-02-02

Thank you so much!

satoko68 (author)2015-01-30

I'm absolutely astounded by this project. Probably the greatest creation I've seen in quite some time, to be honest. Creative as all hell & absolutely gorgeous. I'd keep these up all year long as my front or back yard - or both - display. Unfortunately, we live in a condo :-( Regardless, consider me completely blown away. Thanks so much for sharing this!

RaniaPeet (author)satoko682015-02-02

Thank you so much satoko! I really appreciate the kind words! I too have been wanting to bring one inside as a floor lamp, with a pull string :)

satoko68 (author)satoko682015-01-30

OMG I just suddenly pictured one of these shrooms *inside* our condo! It would be like living with a functional art installation!

edwardo1853 (author)2015-02-02

Theflorifant! That would be so awesome! I dont have any artistic skill.

edwardo1853 (author)2015-01-30

Could you make smaller versions? For my computer desk? Usb powered? And that would change color! Omg i would so but it. Please make one! :)

TheFlorifant (author)edwardo18532015-02-01

I think that easily done. You just need less material, some rainbow leds and you are done. If you want i would build one for you or make an 'ible.

kedwa30 (author)2015-01-29

Store them? Ha! These are so awesome I'd leave them up all year round. My question is how do they fair in the weather? I'm considering making one using hypertuffa instead of foam. Smurfs!

Great 'ible!

RaniaPeet (author)kedwa302015-01-30

Everything is meant to be outdoors, except the underside spandex gills. I'm still trying to figure out how to make gills weather proof. But I do use them outside. I just have to detach the gills when i store them.

PhantomX999 (author)RaniaPeet2015-01-30

Have you tried scotchgard? I don't know how well it would work with spandex. Use the right one "should" make it water proof but, it still might dry rot.

jconover2 (author)2015-01-30

omg aWsome

dvivster (author)2015-01-29

OMG!! You are the! Your creatvity is mind blowing.

RaniaPeet (author)dvivster2015-01-30

hahah thank you so much!

edwardo1853 (author)2015-01-30

If you could make this a usb desk lamp id pay a crap ton for this!!!

YarivA (author)2015-01-30

beautiful and inspiring

HAL 9000 (author)2015-01-28

I need a sound-reactive giant quarter mushroom in the corner of my living room! This is such a great idea!

RaniaPeet (author)HAL 90002015-01-29

Thank you Hal! Sound reactive would be so awesome!

HAL 9000 (author)RaniaPeet2015-01-29

I'm seriously considering it, if i go through with it i'll be sure to post pics/details!!

Leopardstripes (author)2015-01-29

I love everything, positively EVERYTHING about these! Thanks so much!!! :D

RaniaPeet (author)Leopardstripes2015-01-29

Thank you and you're so welcome! :)

knutknackebröd (author)2015-01-29

looks awesome! you should add some speakers and / or lights behind the gills to make them extra trippy

Speakers would be awesome. I did put lights inside and would love to turn one into a floor lamp with a pull string :)

haha had another idea; build in a cheap cuckooclock and have a pixie / gnome pop out once in a while:P

hahah yesssss

vbanaszak (author)2015-01-29

These look awesome! Such a fun design.

RaniaPeet (author)vbanaszak2015-01-29

Thank you so much :)

nice sister (author)2015-01-29

totally incredible. what a huge vision you have. what's the awesome music in the video?

RaniaPeet (author)nice sister2015-01-29

Thank you! The music is Say Yes (instrumental) by Wax Tailor.

fixfireleo (author)2015-01-29

awesome! but are they MAGIC mushrooms?

RaniaPeet (author)fixfireleo2015-01-29

hahah thanks! Do not eat these bad boys!

mrfoltz (author)2015-01-29

Thanks for showing how you used the spray foam too. :)

RaniaPeet (author)mrfoltz2015-01-29

Thank you! I love working with spray foam.

jbarziza (author)2015-01-29

This is a great instructable. I love it when people take common materials and make free-flowing, unusual creations. If you haven't already done so, you might want to look at what people have done with ferro-cement and laminated ferro-cement. Thanks for detailing your work on these mushrooms.

RaniaPeet (author)jbarziza2015-01-29

I've never heard of ferro cement. will definitely check it out!

About This Instructable



Bio: Special event designer and production artist
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