Introduction: Rock Cacti Terrarium

hey! lets make a terrarium with cacti that you don't need to water....ever!

the cacti are painted rocks aka super rad.

I used alot of modge podge in this you can use less. it does dry clear though so I will post a new picture when it has dried completely (see last step. I made the one with pink sand with alot of modge podge and that is how it is now! (i will post a better picture of that tomorrow)).

This terrarium literally requires 0 care aka would be a great present for your friends and family members who do not have a "green thumb"



Step 1: Gather Your Materials (aka Lots of Rocks and Some Other Things)

for this instructable you will need:

1) rocks

-a bag of large rocks (for cacti and leftovers are used at bottom of terrarium)

-a bag of medium rocks (for a few cacti and middle of the terrarium

-a bag of pebbles (for top layer of rocks)

2) modge podge (get a bottle on larger size)

3) sand in whatever color you want! (see last step for another one I made with pink sand)

4) paint

-a few shades of green for the cacti (or just one shade. depends on what colors you want cacti to be)

-colors that arent green for the flowers (optional)

-puffy paint or glass writing paint to easily draw the thorns. you can use regular paint and paint brush if you want but it will take more patience and a steadier hand!

5) disposable bowl

6) disposable spoon

7) disposable knife (optional. can also use end of spoon)

8) paint brush

9) glass bowl to hold everything (and for classic terrarium look)

Step 2: Separate Your Rocks

-separate the rocks you want to use for the cacti from the others. i chose to have 8 cacti in my bowl. Look at the size of the bowl you have and the rocks to figure out your number of cacti.

I aimed for more rectangular stones rather than square like stones. Also consider if it has a side that would be easy to glue down.

-set the cacti stones aside. we will be working with the other rocks first.

Step 3: Start Gluing the Rocks in the Bowl!

-Pour some modge podge into the bottom of the bowl. We want a decent layer that covers the bottom.

-Use knife or end of spoon to smear some of that modge podge onto the immediate sides of the bowl. (So when we start putting down the rocks, the rocks near sides will be glued to both the bottom of the bowl and the side of it).

-start with the remaining largest rocks you have and place them at the bottom of the bowl and towards the sides of it (so when the modge podge dries, we can see that there are some big rocks down there!

-add other rocks to the modge podged areas.

-When you run out of spaces that have modge podge on them, paint some more modge podge on top of that layer of rocks so you can adhere the next layer of rocks to this layer. Make sure your layer is of decent thickness. the modge podge dries clear and if you don't use enough it wont all be glued together well enough!

-wait till the next step to do the small pebbles

Step 4: Its Pebble Time!

-Pour some of your pebbles into your disposable bowl

-pour a little bit of modge podge on top of those pebbles (hint you can always add more modge podge to the bowl but cant really take any out)

-mix it up so that all of the pebbles are covered with modge podge

-move on to the next step immediately

Step 5: Put Pebbles Into Bowl

-use disposable spoon to add the modge podged pebbles to the terrarium. It is important to fill the bowl evenly so dont neglect the edges! We want to make sure there is a layer of pebbles at the edges because if there is then the final terrarium will look more rad.

-if you see lots of white do not fret! It will dry clear (may take a few days depending on how much you used).

-if you need more pebbles, repeat the previous step then this step again. I used my whole bag of pebbles.

Step 6: Cacti Time!

-Take your cacti rocks and various green paints and paint the base color of the cacti onto all of these rocks. If you only have one dark green and one light green paint, you could try mixing them together at different amounts to achieve more shades of green for the cacti.

-Let dry completely

-paint another layer of paint if necessary and let dry completely


-use your puffy paint or glass writer to draw some thorns onto your cacti

-let dry completely

-use your other colors of paint (besides green) to paint a few flowers on a few cacti if you desire and let dry completely.

Step 8: Optional: Spray Varnish the Cacti

I am choosing to put varnish on my cacti to better protect the paint on the rocks. Also I just really like Krylon Crystal Clear and use it alot.

-Follow instructions on spray varnish bottle to coat your rocks in a coat of acrylic coating/varnish

***tip*** if you choose to paint the sides of the rocks that arent painted, wait till the other side is dry first! or if you painted the entire rock, spray one side of all the rocks first then let dry and repeat that for the other sides of all the rocks.

Step 9: Glue the Cacti Into the Terrarium

-Use your hot glue gun to glue the cacti into the terrarium in an arrangement of your desire. Just remember that large cacti in the front will block admirers of your terrarium from seeing the little cacti behind it so place them accordingly.

Step 10: SAND STEP!

-pour A LITTLE modge podge into the disposable bowl.

-pour sand to fill the same bowl halfway

-mix with disposable knife or spoon

-use spoon to place spoonfuls of sand around the cacti and then press down. The "pressing down" part is extra important at the sides of the bowl because if you don't press the sand so its touching the pebbles below, it'll look like you have some gravity defying sand in your terrarium which some would find distracting.

-continue this until the entire top of the terrarium is covered in sand and you have a decent thickness of sand visable from the side of the bowl (you pick how much you want there)

-let dry completely

-optional step: to make the top of the terrarium look more natural, paint the top of the current sand layer with a thin layer of modge podge and cover with loose sand from the bag. You can either dump the extra out after it dries or leave it in there (but if it falls, sand will fly out!)


You're done with your rock terrarium! Its now time to sit back, relax and not water your cacti terrarium because they are rocks and watering it would be unnecessary and weird :) haha

please post pictures if you make one and vote for it if you desire!

Thanks! Hope you enjoyed it!


Step 12: Other Example

I made this terrarium for the fair this past summer

Made blue cacti and used pink sand because they were going to be "space cacti" but I never got around to painting the back of the bowl to look like space.

Homemade Gifts Contest 2015

Participated in the
Homemade Gifts Contest 2015

Indoor Gardening Contest 2015

Participated in the
Indoor Gardening Contest 2015