Plants are the most important inhabitants for a closed terrarium. Since a closed terrarium is hermetically sealed, no new oxygen can get in. Without plants, animals in a closed terrarium could not survive for long and would suffocate. Besides, plants are of course also very beautiful to look at. It is especially interesting to watch them conquer their environment in your closed terrarium. Of course, the question arises, which plants are suitable for a closed terrarium and which you should rather not use.
What distinguishes a closed terrarium from a pot?
A closed terrarium differs in various aspects from ordinary keeping in a pot or flowerbed. The hermetic seal plays the most important role. It ensures that three cycles are formed in a closed terrarium.
You can read more about the oxygen cycle, the nutrient cycle, and the water cycle in this article.
Apart from the amount of light and the temperature in your closed terrarium, you can't influence at all how the conditions develop in there after the initial setup. Therefore, you must either make sure that the conditions are just right for your chosen plants, or go straight for stable plants that can cope with different conditions.
Isn't a closed terrarium just a greenhouse?
No, a closed terrarium is different from a greenhouse. Greenhouses are designed to protect plants from wind and weather and to be able to provide them with a higher temperature and humidity. You can read more about the discovery of the greenhouse effect in the article about the Wardian case.
Unlike closed terrariums, however, greenhouses do not form cycles. They are not hermetically sealed, since people want to go inside their greenhouses from time to time. Therefore, there is no real oxygen cycle.
The water cycle also does not occur because water can escape through the circulation of the air via the humidity. The nutrient cycle also does not occur because not the entire floor consists of substrate.
Which plants are suitable?
In principle, you can take all plants that you find in your garden, on the roadside, in the forest or anywhere else outside. If you can recreate the outdoor conditions in your closed terrarium, your plants will usually do very well.
Some plants are seasonal and behave differently throughout the seasons. For example, these are most plants that bear fruit. For example, in my first closed terrarium I planted a strawberry plant.
In December 2020 she was very small and petite. In spring and summer it overgrew the whole terrarium and now, in October 2021, some leaves are gradually dying off so that it becomes smaller again.
Moss - The most resistant plant
There are extremely many types of moss, all of which look quite different. Some of them you may not even have noticed, even if they are right under you.
Most species of moss are incredibly hardy. Hot and cold temperatures do not bother them, some survive absolute drought and many also need hardly any nutrients. I've written about moss here a time or two. I recommend the following two articles if you want to learn more about it.
Weeds can look nice too
Everyone knows weeds, but what are they? In any case, it is not a biological term. It does not describe a genus of plants. Weeds are only the plants that we actually do not want to see in our gardens. For a closed terrarium, however, many plants of it can come into question.
Dandelions can be very interesting. First it has a beautiful yellow flower, and as you probably know, it turns into a fluffy dandelion as it grows. Dandelions are often seen growing on the side of the road. Sometimes it comes right out of the joints between the stones. It is a very hardy plant and will do well in your closed terrarium.
Alternatively, thistles, for example, can be nice. They form a beautiful purple flower and do not look like weeds at all. Maybe you want to have a nice lawn in your closed terrarium. Then you can also choose clovers.
Nettles are also weeds, but you'd probably rather make tea from them than plant them in your closed terrarium.
Orchids - Difficult, but worth the effort
Orchids in any case can not be compared with weeds and moss, of course, apart from the fact that all of them are plants. They are very complicated to keep and need very specific conditions.
On the one hand, they constantly need high humidity, but should not be in waterlogged conditions. Also, their beautiful flowers should not get wet. In addition, they need a lot of light, but should not be in full sun. However, if you get all the conditions right, it is worth it. After all, they are not called queens of flowers for nothing.
If you want to learn more about orchids, I recommend you read the first article here. If you just want ideas for closed terrariums with orchids, read the second article.
Bonsais - small trees for the windowsill
Bonsais alone are beautiful to look at. But if that's not enough for you and you don't want to water it regularly, you can plant it in a closed terrarium. There you can even see insects crawling around on it or watch how other plants grow there.
Although bonsais are quite small for trees, they are very large for most closed terrariums. So you should consider them if you are planning a large closed terrarium anyway. They are not as difficult to keep as orchids, but you still need to pay attention to a few details. You can find a suitable article for that here as well.
Carnivorous plants - confined and harmless
Carnivorous plants are super popular in households and are also often purchased for children. True, they get their nutrients from insects flying by. But you still have to water them. So it would be quite interesting if you could keep them in a closed terrarium.
The question naturally arises whether carnivorous plants can survive without a constant supply of insects. You can't give a blanket yes or no answer to that question. In my article on carnivorous plants for closed terrariums, I looked at the different types of carnivorous plants and which of them are suitable for closed terrariums.
You can find out all about Venus flytraps, sundews and pitcher plants in the article below.
For closed terrarium, many different kinds of plants are possible to keep. The easiest is moss, as it is very hardy and does well in almost any environment. Weeds from the garden can also be very nice. If you want something more extravagant, orchids, bonsais or carnivorous plants come into question, but you have to pay a lot of attention to the right attitude. You can find the necessary knowledge about all these plants on the Terrarium Blog.