Introduction: Grow Your Own Magic Crystal Tree

Picture of Grow Your Own Magic Crystal Tree

If you found an ad for this instructable in the back of a comic book, it would read something like:
"Amaze your friends by growing a crystal tree out of common table salt and a few other ingredients available from the grocery store"

Step 1: Gather Your Materials

Picture of Gather Your Materials

Gathering the ingredients is probably the most difficult step. To grow your Magic Crystal Tree, you'll need:
- Mrs Stewart's Bluing
- Table salt
- Household Ammonia (the kind with no soap added)
- Cardboard (not corrugated)
- Bowl
- Water
- Measuring spoon
- Food Coloring (optional)

The bluing is the hardest item to find but can be found in the cleaning section of many grocery stores. You can find the ammonia close by.

The cardboard I used came as packing material from a new shirt, or the backing from a paper notepad. Cereal box cardboard might work, but it's thinner & has printing on one side...

Depending on the temperature & humidity of your location, the ammonia is optional, but speeds up the crystal growth -- the tree in this Instructable started "sprouting" in less than an hour. Without ammonia, it may take a couple of days to start.

Step 2: Cardboard Shapes for the Crystals to Grow On

Picture of Cardboard Shapes for the Crystals to Grow On

For this Instructable, I made a tree formed out of two cardboard triangles, roughly 2" at the base and about 3.5" high. If you'd prefer some form of unspeakable tentacled beasty, send me a picture!

Cut a slot from the top to the middle in one piece, and from the bottom to the middle in the other. The slots allow the two pieces to be assembled into a 3D shape.

Make sure that whatever shape you create can stand up by itself.

Step 3: (Optional) Color the Tree

Picture of (Optional) Color the Tree

If you like, you can add a little color to your shape by putting drops of food coloring on the edges. The food coloring will soak into the cardboard.

Step 4: Adding the "Magic" Solution

Picture of Adding the "Magic" Solution

The "Magic" Solution -- Mix together:
- 1 tablespoon water
- 1 tablespoon salt
- 1 tablespoon bluing
- 1/2 tablespoon household ammonia

I put everything into a small bottle that could be shaken to mix the ingredients.

Again, the ammonia is optional, but I'd recommend it.

Find a place where you can watch your magic tree grow undisturbed for a few days.

Put the tree into the bowl and add the solution

Step 5: Wait...

Picture of Wait...


Wait a little longer...

More waiting...

(First sign of growth showed up at around the one hour mark...)

Step 6: Time Passes

Picture of Time Passes

The tree after 12 hours.

You can keep your crystal shape growing indefinately, by adding more water/salt solution to the bowel.

Step 7: What's Going On?

Picture of What's Going On?

The salt solution is wicked up into the cardboard tree via capillary action. Water evaporates from the surface of the tree, forcing the salt to crystallize out.

Mrs. Stewart's Bluing is a colloid -- tiny particles suspended in water (think of glitter in a snow globe, but much, much smaller). The tiny particles make it easier for the salt crystals to form.

The ammonia helps speed up the evaporation process, which makes the crystals grow faster.

There's a more detail explanation available from Mrs. Stewart's Bluing at

Step 8: Filming the Crystal Tree Growing

Picture of Filming the Crystal Tree Growing

I set up a Canon PowerShot A40 with remote capture software to take one picture every minute.

The halogen desk lamp overhead is an attempt to provide a consistent light source, as well as warming things up a little (to speed up evaporation).


miraclebaby (author)2017-10-22

what is the scientific effect of the bluing?

miraclebaby (author)2017-10-22

Hello! I would like to know which is the scientific effect of the bluing on the growth of the crystal tree. Thanks a million!

CeciliaF7 (author)2017-04-30

Mrs. Stewart's bluing is a colloidal suspension of extremely minute particles of blue powder ferric hexacyanoferrate Fe4[Fe(CN)6]3.

Prince_Gumball made it! (author)2017-03-13

Mrs. Stewart's Bluing is also sold at Woodman's. The one on the right of my picture is way too high with such low amounts of ammonia/solution to cardboard height ratio. The right is also made out of cereal box and it didn't work as well as a thickly layered cardboard as seen on the left.

The solution also didn't come out as blue as seen in the instructions as the blue mixture eventually turned an orange rust color.

Sassy-Cindy (author)2017-03-06

This would make a great craft to get the kids involved with as long as an adult was present to handle the ammonia and blushing!!! Both of these ingredients can cause a lot of damage to a small child!!!!! I'm sure children would love to watch these grow!!

bn5 (author)2016-05-22

Ace Hardware sells Mrs. Stewart's Bluing 8oz for $4 and will ship free to your local store.

love scientific stuff (author)2016-03-30

Why does it grow?
What chemicals are reacting?
Why does ammonia help it grow faster?

If you look at step 7, mik3 explains it a little there. You can also Google "how to grow crystals" and find lots of stuff about it. You can grow crystals from other things too, like borax and Epsom salts. It's really fun and easy to do.

Thanks it's because I have a science project coming up for school

catarinapires (author)2016-01-20

It´s very hard to find the bluing in the UK. The only way is to order it from ebay and the shipping costs are quite expensive. I did some search and found this: RECKITT'S CROWN BLUE. Has anyone tried it before? Thanks,

I have never tried this, so I can't say for sure if it would work. I do know that you can grow salt crystals without using any kind of bluing.

Did u try it yet

Sorry, no. I had plans to do crystal growing, but I just haven't been able to do anything that I want to do lately.

love scientific stuff (author)2016-03-30

I found Mrs. Stewart's bluing at meijer's for $2.00 maybe because im in Chicago

love scientific stuff (author)2016-03-30

I found Mrs. Stewart's bluing at meijer's for $2.00 maybe because im in Chicago

OloloH (author)2016-03-18

where you keep the tree? Ammonia is very stink in apartament. Where to put? Or how can i do this?

lherna1 (author)2015-12-03

Do you know if using a Borax solution would work instead of the bluing solution? I am having a difficult time finding it?

ThisIsMyNameOK (author)lherna12016-03-13

You can grow crystals from borax very easily. The process is a little different and the crystals have a different structure, so they won't look like these. It is also possible to grow the salt crystals without using laundry bluing.

mik3 (author)lherna12015-12-04

I think you'll have the best results if you can find Mrs Stewart's Bluing. In the comments for another instructable (, they mention other kinds of bluing not working.

You can try Amazon, or directly from

ood luck!

alexiana2 (author)2016-01-22

These crystal trees are cute! I'm gonna make one as soon as I get the things to make it.

terriilyn (author)2015-04-09

I remember doing this with my "Mimi". (grand mother) I am now a Mimi and look forward to doing it with my grand children. I never would have found the recipe with out your "ible" probably wouldn't have thought to. so thank you.


the discoverer (author)2014-11-04

Nice . Thanks for posting this :)

kittivalentine (author)2011-11-23

Two questions:
1) You said the ammonia was optional, depending on humidity, etc. I live in one of the rainiest cities in America so it's always very humid here, so would that make the ammonia more or less important?
2) If I wanted to make little kits as gifts, where I pre-mixed the solution and kept it in a bottle, do you know if it would keep and for how long?
Thanks! BTW, great instructable!

panakanic (author)kittivalentine2012-10-03

My Mom used to do this for us, when we lived in Seattle, back in the 1960's, and it worked fine-she always used ammonia.. We used charcoal briquets for the base then, but any thing that is somewhat porous will work for the crystals to grow on. Using briquets gave kind of a fairy-land look to the creation. Mom would put the briquets and solution in a pie plate, and let my sis and I put drops of liquid food color on the briqs to make the different colored areas, Magic to little kid! Just make sure they don't try to play in it!

sylbl12 (author)2012-10-01

I remember buying kits for my children, am looking for activities for my grandchildren over the holidays, this is definitely a good idea, thanks for sharing.

neetz (author)2012-02-28

i just have a question, can you use horse bluing? the kind that makes them white?


Oliver Larsen (author)2009-12-05

So, it's a great instructable, undoubtly gonna try it. BUT, I'm from Denmark, and therefore I don't understand what "Bluing" is. Can you explain for a Dane?


It's a additive used to make whites whiter in the laundry.  It was quite popular years ago, but not widely used now.

Uh, I see. Do you think chlorine could be a good alternative?


If you don't believe it from me, then read this.

cdeerinck (author)Oliver Larsen2010-04-10

 No, no, no!  Ammonia tries to evaporate, and will carry the chlorine with it.  I almost died once from breathing chlorine.  Probably the worst way imaginable to die. 

Also, don't try bleach (another whitener), as mixing that with ammonia makes truly dangerous things.  Read here:

No, I wouldn't think so.

Denmark!! Me too!! Well no my mom is, dad isn't, i'm half-and-half!

onyx95 (author)2011-12-13

Oh my goodness I haven't done this in such a long time. My kids are going to love it.
Thanks so much for sharing it.

museumoftechno (author)2010-05-02

Does the bluing do anything, apart from colouring the salt? Would the project work without it?


ggibbs2 (author)museumoftechno2011-11-20

the bluing is a colloid aka the crystal seed you need it to grow the crystals it otherwise is just a mix trust me it doesn't grow a thing.

tiag79 (author)2011-07-18

This looks interesting but I'm not too sure I want to try this just yet. Maybe when my 4 year old it 5 or 6. She'll probably think it's candy from the coloring, lol. But I must admit that I think this would be a nice science experiment for my 13 yr old to give a try.

superMacaroni (author)2011-03-20


It's bowl, not bowel.

claudiapatx (author)2011-01-12

Cool. I remember buying kits that we did this with as a kid in the 70's...Magic Grow or something like that. They really made a killing off of us kids, didn't they?

CraftBear (author)2011-01-08

Would it work with any shape "tree" do you think?

mik3 (author)CraftBear2011-01-11

It should work with any shape, but it's best as long as the material is porous ...
As a kid, we used charcoal briquettes, and there's another instructable that uses a toilet paper tube:

RMDelete (author)2011-01-07

I think I just had a "bowel" movement here :)

mik3 (author)RMDelete2011-01-11

Hmmm, if I fix the instructable, nobody will know what you're talking about

D00M99 (author)2011-01-05

I see in the video that the crystals fall off sometimes. Any way to prevent?

Also, any scientific reason as to why this happens? Very interested in the process.

mik3 (author)D00M992011-01-11

The crystals are pretty fragile, so when get too big they break & fall off by themselves. Growing them in a place where they don't get jarred too much can help.

alienpsychomom (author)2009-01-12

Do you think you might be able to use the cone styrofoam? The food dyes would certainly be absorbed. I will go ahead and try it unless you know why it would not. I will email you a picture of it if it turns out great. Thank you for the idea because I have grandkids that would it.

skylane (author)alienpsychomom2010-02-14

 YEARS ago, my grandmother and I did this very same thing.
We used pieces of brick.  Made a little pile like a small mountain range.
Then the ''forests'' grew!!  Place drops of different colors of food coloring
in different locations for a multi color effect

briannamarie21 (author)2010-02-08

uuuhhhgggh!!? i need your help.? my tree is taking forever to grow, help me, did i do something wrong? HELP! its a goood idea thoughh(:

MissMush (author)2010-01-07

Just though I would jump in here:  If you are trying to find the Mrs. Stewarts Bluing - check this list of all the stores in Canada/USA that stock it!!

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