Growing a crystal tree was on my big 2018 list of science projects I wanted to try out. We did this in the summer for my Christmas in July community science show, but life has been insane with all of my class offerings that it has taken 5 months to write it up. And now it actually is Christmas time, so I figured, why not incorporate this into our christmas science projects list? It fits perfectly, especially if you decide to grow a magical Christmas tree our of crystals.

My littlest wasn’t super happy about growing just a Christmas tree – so our project turned into growing a Christmas village – I’m sure we could even make up stories of tiny elves getting stuck in the crystal snow, or Santa taking off from the rooftops.

Project Ingredients:liquid bluingsaltamoniawashable markersplastic containeregg cartons or cardboard

How to grow a crystal Christmas tree

Create your tree or village

Create a mixture of:

1 part water1 part salt1 part bluing1/2 part ammonia

To grow a single crystal Christmas tree you wee need 1 part to equal about 1 tablespoon. To create an entire crystal village you will need a bit more.

Wait

1. Create your tree or village

Using recycled egg cartons or corrugated cardboard you can cut our any design you want for your Christmas tree. If you cut out two identical copies you can add in slits to allow them to stand up in the solution. If you want to keep them as 2D you can prop them up in the crystal growing solution. The more elaborate your tree the fluffier it will be since the salt will have more places to seed its crystals from.

You can color your tree using washable markers or concentrated food dye on the cardboard.

2. Mix your solution

1 part water1 part salt1 part bluing1/2 part ammonia

To grow a single crystal Christmas tree you will need 1 part to equal about 1 tablespoon. To create an entire crystal village you will need a bit more.

3. Place your creations in the solution

Pour your solution at the bottom of your glass or plastic container. Then you can add in your tree or other village creations that you want to grow crystals. Stabilize each piece since it will take a few hours to start seeing the crystal formation.

4. Wait

It takes time for capillary action to suck the solution up the paper trees. Once the trees are saturated the salt will begin to form crystals at the edges where the solution will dry out faster.

Why do I need bluing or ammonia if I am making salt crystals?

The ammonia helps the solution evaporate faster, allowing your salt crystals to grow more quickly. The bluing agent disrupts the natural crystal structure of salt, which is cubic and allows it to form a more ‘snow like’ structure.