People say that terrariums are the easiest way to keep houseplants alive, so it’s not surprising that many first-time owners get upset when things start to go wrong after a few months.
Perhaps the glass is misty and filmed with a green goo. Or, a fern’s once-tidy leaves have grown so big that they might push up the lid and suffocate the other plants. Or, worse of all, there’s just a pile of brown, moldy mush where a succulent once stood.
There are a lot of websites and books with terrarium projects, but not many of them go into detail about how to fix problems or say that even the most carefully planted terrarium will probably need to be redone once or twice a year. This partly depends on the size of the pot. Recently, botanist James Wong said that a terrarium that is at least 30 by 30 centimeters (12 by 12 inches) is much more likely to give plants a stable, long-term environment. You can keep plants in glass pots that are smaller than that, but don’t expect them to look the same in a year.
Terrariums are touted as being low maintenance, but even the best-planned container garden can run into trouble. Maybe the glass has become covered in green scum plants are drooping or there’s the horror of discovering mushy black plant remnants. Don’t give up hope! With some troubleshooting and TLC, it’s often possible to rescue a failing terrarium. Follow these tips to revive your plants and restore the mini ecosystem to good health.
Assess the Damage
Carefully observe the terrarium to pinpoint any issues. Are there signs of decay like mold or fungus? Are plants wilting or dying? Does the soil appear too wet or bone dry? Is algae growing on the glass? Diagnose the problems before taking action. The most common killers of terrarium plants are overwatering, intense heat and lack of air circulation.
Fix Watering Issues
The most frequent reason for terrarium decline is improper watering If plants are wilted, soil is muddy, and condensation is excessive, reduce watering frequency Allow more ventilation to lower humidity. Remove soaked moss atop the soil and replace with dry sphagnum moss to absorb excess moisture.
If plants are shriveling and soil is dusty dry, give small amounts of water directly to the base of plants using a pipette or spray bottle. Mist the moss layer delicately. Increase watering frequency and monitor soil moisture closely.
Adjust Light and Temperature
Plants turning brown or leggy often indicate too much light or heat. Move the terrarium away from sunny windows and add sheer curtains to filter light. Cool rooms with air conditioning or fans to keep temperatures moderate.
If plants are small and compact, they likely need more sunlight. Slowly move the terrarium to brighter spaces, watching for signs of stress. Rotate the container so all sides get even light exposure.
Increase Air Circulation
Stagnant air and high humidity create a breeding ground for mold, algae and fungal diseases. Improve airflow by propping open the lid with a stick for a few hours each day. Add a small battery operated fan to gently circulate the air. Just don’t leave the lid open too long or plants may wilt.
Prune Overgrown Plants
It’s easy for terrarium plants to become overgrown. Carefully trim back any plants touching the glass or overwhelming their neighbors. Cuttings can be propagated in potting mix to replant later. Pruning increases air circulation and light penetration.
Clean the Glass
Wipe down interior glass walls with paper towels and plant-safe cleaners like diluted vinegar water or lemon juice. Use a soft cloth to gently scrub away algae buildup. Rinse and dry the glass thoroughly before replacing plants. Repeat cleaning regularly to prevent future scum.
Remove Dead Material
Clear out any rotting plant matter, dead leaves and stems, or contaminated soil. Clip away dead roots and scrub plant containers to eradicate mold spores. Replace any decaying moss. This eliminates sources of disease and gives plants a fresh start.
Consider Replanting
If many plants have perished or the terrarium is beyond saving, it may need replanting. Wash out the container with hot water and plant-safe soap. Use new potting mix and rinsed pebbles or gravel for drainage. Select plants suited to the new lighting and humidity levels. Adjust watering and maintenance routines to avoid more issues.
With attentive troubleshooting and care, even severely neglected terrariums can make a comeback. Be patient and allow enough time for plants to recover between adjustments. A revived terrarium may not look exactly like the original, but with some trial and error it can thrive again. Just don’t allow problems to progress too far before taking corrective action. Catching issues early makes salvaging a failing terrarium much easier.
The Plants Are Leaning to One Side
Your specimens are probably trying to grow towards the light source. Every few days, turn your terrarium a little so that all of the plants get the same amount of light. If the plants start to grow tall, move the terrarium to a brighter spot that isn’t in direct sunlight.
The Glass is Dirty
If your glass is green, it’s a sign that algae has started setting up home. If you have a big tank aquarium with flat sides, it’s easy to get rid of algae. You can use an aquarium scraper or even an old credit card. On curved glass, paper towels or a clean rag are perfect. If you can, use rainwater or distilled water to fix the problem. White streaks are usually caused by mineral buildup from watering with tap water. If you wet a cloth with lemon juice or vinegar, you might be able to get rid of the streaks. Just make sure to keep this away from your plants. Then follow up with a cloth dipped in rainwater or distilled water. If that doesn’t work, you’ll have to take the terrarium apart, clean the glass with vinegar, rinse, and put it back together again.
Terrarium Tips – FIVE Mistakes Beginners Make
FAQ
How do you fix a dying terrarium?
How do I bring my terrarium back to life?
How to refresh a terrarium?
Can a terrarium get too long?
Yes, if your plants in a terrarium get too long, there’s a higher risk of them dying. That’s because long plants will touch the sides of the terrarium and catch water that can lead to plant rot. If your plants get too long or big, make sure to prune them a little. It’s always a good idea to choose slower growing plants for a terrarium.
Can terrarium plants die?
While terrarium plants can die, it is not a common occurrence. There are a number of reasons why a terrarium plant might die, including: too much or too little water, too much or too little light, and improper care. However, if a terrarium plant does die, it is typically because of one of these three reasons.
How do you care for a terrarium?
To care for a terrarium, surround the roots with soil, leaving no air pockets. Every once in a while, clean the glass inside and out. If the glass is too dirty or foggy, it will be difficult for light to reach your plants. Use a damp piece of newsprint or a lint-free cloth to clean it.
Why are terrariums dying?
Few of the main reasons why terrariums are dying include overwatering the plants or soil, using wrong containers for terrariums, mixing plants with different requirements, positioning terrariums in wrong spots. Overwatering plants in the terrarium is one of the most common mistakes and reasons why terrariums start dying.