How to Build an Indoor Succulent Garden

Believe it or not, there's an almost indestructible type of plant that virtually anyone can grow. This is true whether you're a non-gardener, a would-be gardener, a forgetful gardener or a truly awful gardener cursed with the blackest of black thumbs. If you're wondering what in the world this plant could be, welcome to the forgiving world of succulents.

The reason anyone should be able to grow succulents is that if you follow a few simple guidelines, all you need to do is leave them alone. They won't need much help after you've potted them up, especially when it comes to watering. That's because succulents are from arid regions and their leaves and stems have evolved through the eons with the capacity to store water so they can survive extremely dry conditions. This is a particularly advantageous characteristic because American homes typically have humidity so low that it has been compared to that of the Sahara Desert. It's not particularly good for people or most of their houseplants, but it's ideal for succulents.

There's something else appealing about succulents. They come in an amazing variety of sizes, shapes and forms, including some that look like they're more suited for a rainforest than a desert, and an endless array of textures and colors. What more could you ask for from one group of plants?

Perhaps the easiest way to grow succulents is in a tray garden. As the name implies, tray gardens are shallow containers. They're ideally suited for succulents because succulents typically have very shallow root systems.

Before you start, it's important to understand that tray gardens are very different from terrariums, and that succulents are not suited for terrariums. Terrariums are enclosed glass containers that retain significant amounts of moisture and humidity and don't have much in the way of air flow. Think of them as tiny tropical rainforests. (And if you want to know how to create one, read how to create a terrarium in 5 easy steps.) Succulents can't tolerate constantly moist conditions, which would essentially cause the plants' roots to rot.

Here's how to create your own succulent tray garden in six relatively easy steps.

1. Choose a container

Almost any shallow container will do. You're only limited by your imagination. That container may be a planting dish, pot or saucer you find in a garden center, a decorative knick-knack you have on hand, something you found at an antique store or a planting tray you found online. The most important considerations are that it be shallow enough to be compatible with the shallow root systems of succulents and that it has a drainage hole. It's possible to grow succulents in a container without a drainage hole, but you'll need to be very careful when watering to prevent the planting medium from becoming soggy. If your container doesn't have a drainage hole, you could drill one or create drainage by adding a layer of pea gravel or small rocks on the bottom.

2. Select a potting soil

The simplest choice for a potting soil is to purchase a prepared mix created for succulents. If you can't find a prepared mix at a local garden center, you can make your own. A simple formula for a succulent potting mix is one part regular potting soil, one part perlite and one-quarter part coarse builder's sand (not play sand).

3. Select the plants

There is an almost endless variety of choices for plants in such genera as Echeveria, Crassula, Kalanchoe, Senecio, Haworthia, Sedum, Sempervivum, Aeonium, Sedeveria and Graptoveria, not to mention the whole cactus family. And the list could go on from there. Whatever you like in terms of plant shape, color and texture, the chances are excellent that you can find that quality in succulents. And what you can't find at local stores you can almost certainly find online.

4. Pot the plants

If your container doesn't have a drainage hole, start the potting process by beginning with a bottom layer of rocks or pea gravel, as mentioned above. Then add a layer of the potting medium. If you have a drainage hole, just add the potting mix. Don't fill the container to the top, though. Just put in a thin layer. The idea is to leave enough room at the top of the container to add a surface layer of small gravel or sand to act as insulation.

Break up the roots slightly to promote new root growth and help the plant develop a strong root system. Then nestle each plant partly into the mix, arranging them in a manner that's visually pleasing to you. With succulents, it's OK, even preferred, to crowd the plants together.

With the plants in place, there will be a vertical gap between the base of the plants and the potting medium. Work the potting mix into this gap, filling the potting medium around the plants up to the base of the plants. As you do this, be sure to completely cover the roots, tamp down the soil and make sure the plants are snug in their new home. Cover the top of the soil with a layer of pea gravel, small river rocks or sand just as you would add mulch around plants in an outdoor garden. This top layer will act as a drainage layer that will keep moisture away from the base of the plants and help reduce the possibility of rot. Lightly water the pot to settle the potting medium.

Now for a neat trick! If you wind up with a gap between plants, you can break a piece off many succulents (particularly Sedums) and gently nudge them into the soil and they will often readily develop roots. What an easy way to fill in unexpected blank spaces!

5. Place the container

If you created your tray garden in a warmer month, you can set it outside in a bright area where it will receive indirect sunlight for at least four to six hours per day. Your new succulent tray garden should be able to take direct morning light as this is not as strong as afternoon sun, particularly in a Southern state. You may want to experiment with the location regarding the strength of sunlight, gradually moving the container into the brightest light you think the plants can take. Gradual steps regarding light are always best to avoid shocking the plants (even succulents can "burn").

Generally, avoid low light areas. Too little light will cause the plants to "stretch" for the sun, which will result in weak and spindly growth. Rotate the container a quarter or half turn every several weeks so new growth will spread evenly in all directions.

Bring the container indoors when night temperatures fall to 50 degrees Fahrenheit. Choose a bright location away from drafts and heat vents. As with anything, some succulents will tolerate low and medium light levels. These include Echeveria and Crassula species. Move the container back outside in the spring when night temperatures are consistently above 50 degrees. As before, gradually move the container into the brightest light you think the plants can tolerate.

6. Maintain your garden

All you need to do to maintain a tray garden is to water occasionally and rotate the plants to promote even plant growth on all sides. Under-watering is far better than over-watering. A plant stressed from receiving too little water is much easier to bring back to health than a plant suffering from root rot caused by overwatering. You could try to develop a schedule of watering based on the conditions in your home. Generally, that's no more than once a week. Frequently, the interval could be every two weeks or even longer, especially when the plants are not in active growth. The idea is to let the potting medium become dry before watering. Or, you could opt to wait and let the plants "tell" you when they need to be watered. They will do this by losing plumpness in their leaves.

When watering containers with a drainage hole, water until the water comes out the bottom of the container. If the container does not have a drainage hole, tip it on its side if you think you have added too much water and let the water run out. Be especially careful about watering when the plants are not in active growth. They will need much less water when dormant than when you see new leaves emerging.

Finally, do not fertilize succulent tray gardens. That will cause the plants to grow too fast.

That's it! Now all you have to do is enjoy your tray garden.