Replacing a dead plant in a terrarium, without taking it all apart
A plant has rotted or grown too big? Remove it through the neck, prepare the new one, plant it with tweezers and rebalance the humidity: the step-by-step method.
In this guide
You can replace a terrarium plant without taking the jar apart. Remove the dead plant with its root ball using long tweezers, fill the hole with a little potting soil, plant the new one in the same hollow, then wedge the moss back around it. One or two spoonfuls of water at its foot are enough. First of all, find out why the first one died, or the second will follow.
First, understand why it died
| What you see | Likely cause | What to plant instead |
|---|---|---|
| Black, soft base | Too much water, or a plant that dislikes humidity | A tropical plant, not a succulent |
| Leaves rotting against the glass | Contact with condensation | The same, but planted more centrally |
| Long, pale stems, then collapse | Lack of light | Moss or fern, see low-light plants |
| Plant too big | Normal growth | A slower plant, or a cutting of the same one |
| White fuzz on the stem | Mould | Remove, air, then replant |
Our guide my terrarium plants are dying goes into the diagnosis.
What you need
- long tweezers to grip the plant and its root ball;
- a claw grabber if the neck is narrow and the root ball large;
- a little terrarium potting soil to fill the gap;
- paper towel and a spoon.
Removing the dead plant
- Open the jar and push the moss aside from the base with the tweezers.
- Grip the plant at the base, level with the soil, not by the leaves.
- Pull gently while twisting. If the roots hold, free them with the tip of the tweezers.
- Take out the whole root ball, with the rotting soil around it if the base was black.
- Remove debris: fallen leaves, bits of root. Nothing dead should remain.
The claw grabber is useful for a root ball that will not come out in one piece: it grips and lifts.
Preparing the new plant
- Choose a species suited to a closed jar: fittonia, peperomia, small fern, calathea, selaginella.
- Take it out of its pot and remove some of the nursery soil, which holds too much water.
- Reduce the root ball if it is wider than the neck, teasing the roots apart with your fingertips.
- Inspect the leaves: no spots, no small bugs under the leaves.
Our Jungle refill brings together five plants made for life under glass.
Planting in the hollow
- Fill the hole with a spoonful of slightly moist potting soil.
- Dig a small well with the tweezers.
- Lower the plant in, held by the base, roots down.
- Firm the soil around it with the back of the tweezers.
- Wedge the moss back against the base, without burying it.
Rebalancing the humidity
Pour one or two spoonfuls of water at the foot of the new plant, no more. Wipe the glass if soil has stuck to it. Close it, then watch the glass for three days:
- a little condensation in the morning: all is well;
- the glass streaming all day: open it for a few hours, see should you open a closed terrarium;
- no condensation at all: one more spoonful of water.
When it is better to redo everything
If several plants rot at the same time, if the soil smells bad deep down, or if mould keeps coming back despite airing, replacing one plant will not be enough. Then follow our guide to redoing a terrarium.
In short
- Find the cause before replanting.
- Remove the plant with its root ball and all debris.
- Plant a species suited to a closed jar, root ball reduced.
- One or two spoonfuls of water, then three days of watching.
Frequently asked questions
Can you change a plant in a closed terrarium?
Yes, without taking the rest apart. You remove the plant with its root ball using long tweezers, fill the hole with a little potting soil, then put in the new plant and wedge it with the moss.
Why does only one plant die in my terrarium?
Most often because it did not suit the environment. A succulent in a closed jar, a plant placed against the glass or at the wettest spot rots before the others. Replace it with a species that likes humidity.
Should you water after changing a plant?
A little, only at the foot of the new plant, one or two spoonfuls. The terrarium already has its water. Watering widely could drown the rest.
