Succulents are generally easy to care for and will successfully grow in different growing mediums. There are, however, a few misconceptions about growing and taking care of succulents because of their reputation as hardy plants that cannot be killed.
Many people like to grow succulents in pots and glass jars that look attractive and unusual and placing rocks either on top of potting mix in pots or in glass terrariums is very popular.
Succulents cannot be planted in just rocks for the long term. It is not recommended to grow a succulent in a pot or a jar without potting mix to support the roots.
You can, however, make it look like succulents are planted in just rocks with a few different methods.
If you want to plant succulents in rocks for an event such as succulent bonbonniere or wedding favours, it is possible. Succulents will survive in just rocks for a couple of weeks but are likely to eventually die if left planted in rocks for more than a few weeks.
For the long term, succulents need a growing medium to stay healthy and look good, but there are a few ways of completely hiding the soil to create the illusion that your plants are only growing in rocks. We like to use these methods when creating arrangements for the markets.
Rock or Pebble Wall in a Terrarium or Glass Jar
This method is a little fiddly and will require different sized rocks to hide the soil and to make sure it does not fall through the rocks onto the glass.
First you need to decide on the rocks/pebbles that will show on the outside. Smaller the pebbles the better/ easier to make. Different types of rocks will also create a nice effect.
If your rocks are very large you will need smaller rocks behind them to stop the soil from falling through.
Place the rocks you want to see at the bottom of your glass container (terrarium, jar etc.) and fill any gaps with small pebbles/gravel. You can also use a cloth or geofabric to stop the soil getting on the glass. Build your way around the glass with a layer of pebbles supported by your potting medium (so they don’t fall in as you go higher) until you reach your desirable height. In a terrarium, this may be halfway through the bowl. In a glass jar you may want to keep going all the way to the top.
Take the succulent/s you want in your glass and shake the soil off. If the root ball is too big don’t be afraid to cut a bit. Succulents will not die if you chop a few roots off.
Make a hole in the potting mix big enough for the roots and cover with more potting mix.
With smaller glass jars or terrariums that have narrow openings, you may need a few tools like a spoon, tweezers or a spatula to help getting the plants into position.
Once everything is in place, put more pebbles on top and around your succulent/s to hide the soil visible from the top. A tea spoon is a very useful tool when trying to get pebbles closer to the plant base.
To read another one of our article on making succulent terrariums that last, see here.
Planting Succulents in Plastic Pots in a Glass Jar/ Terrarium
This method is very easy as there is no soil to worry about but you will need the right fit for your glass vessel. Also, you will probably be able to get only one or two plants in as the pots take up quite a bit of space, unless your glass planter is massive.
Firstly check that the plastic pot fits in the glass with ample space around for the pebbles. Place a few pebbles at the bottom of the glass, put your pot/s in and start building around it until you reach your desirable height. Smaller pots (5-7 cm) are easier to work with.
If you would like to make an arrangement and use this method, you can always work with cuttings. This will allow you to put at least 5-6 different succulents in a 10 cm plastic pot.
Planting Succulents in Pots/ Upcycled Cans and Other Containers
To get the rock look in a pot is extremely easy. All you need to do is plant your succulent in the pot of your choice using succulent potting mix. Leave some space on the top for the rocks. Add rocks/pebbles and voila.
If you bought your succulent in a plastic pot and the plastic pot happens to fit into the ornamental pot you want your plant in, even better! Simply place the plastic into the final pot and put pebbles on top until the whole top opening is covered. No mess, no fuss.
Succulents in Rocks and Water
Technically there is a way to grow succulents in rocks, but it is very time consuming and not great for the long term, but possible.
Some of you may have heard of water propagation. Well, you can grow a great deal of succulents in water if the water is changed often enough and only the roots are submerged.
To make this look pretty, you can add rocks to your water, however the changing of the water becomes a massive chore and even more so when the roots start growing through the rocks. Algae will also grow on the rocks and the walls of the glass eventually and cleaning it all may be quite difficult.
We would not recommend this but, if you’re extra keen, you can give it a go.
A Few Things To Remember
When planting succulents in pots or other enclosed vessels (glass, tins etc.) it is best to use a good quality, free-draining potting mix.
Adding a bit of perlite or pumice to your chosen mix will never hurt, though if you can’t be bothered, most succulents will be ok.
Always make sure that the succulent is suitable for the location. If you want to put your lovely new terrarium indoors where the sun does not come through, you will need a succulent that can cope with shade and being indoors such as Haworthia, Gasteria or Sanseveria.
A colourful Echeveria or a similar sun loving succulent will almost certainly not survive indoors for a long time without ample sun light.
For easy care, your pot should have a drainage hole. It is possible to grow succulents in pots/ glass containers with no drainage, but you will have to be extra careful with watering the plants and making sure they are not sitting in water saturated potting mix for a long time. The best way to make sure they are not over-watered is to let the potting mix dry out between watering. Indoors, we usually water our succulents every 3-4 weeks in winter and as needed in summer.
If your pots are outdoors and you are in a part of the world that gets extreme heatwaves (40 C/ 104 F and over) it is a good idea to protect your pots from the sun rays on these hot days. You can do this by moving your pots into a bright but shaded area when hot, sunny days are expected or pitching a 30% shade-cloth over your pots. Sometimes succulents may literally cook in their pots as in the sun the temperature is much higher than what you see in the forecast (forecasted temperatures are always for shade).
Similarly, if your part of the world has snow and frost in winter, bring your pots in. The majority of succulents are not frost hardy. See here to find out how cold hardy succulents are.
Take a bit of extra care with glass terrariums in summer. We have had a few customers placing their terrariums on a window sill and cooking their succulents through the glass. Make sure there is a distance between the window and your terrarium as the glass intensifies heat.