Terrariums, or bottle gardens, are mess-free and easy to care for, creating little landscapes for house plants that are both calming and therapeutic. They’re easy to make, look perfect on a desk or coffee table and make excellent gifts.
An open terrarium is a miniature garden enclosed in a transparent container, open to allow airflow. These indoor gardens are beautiful decor pieces that also allow you to grow small houseplants. However, caring for an open terrarium requires some finesse, especially when it comes to watering.
Understand the signs that your plants need water and techniques for watering open terrariums properly Follow these tips to keep your open terrarium thriving
What is an Open Terrarium?
An open terrarium has an open-top design without a fully enclosed lid or cover. This allows for ventilation and prevents humidity from building up inside.
Open terrariums are ideal for growing:
- Succulents
- Cacti
- Certain ferns
- Air plants
- Some tropical foliage
These plants prefer drier conditions compared to closed terrarium environments The open design allows your arid-loving plants to soak up the sun without sitting in damp soil
Signs It’s Time to Water Your Open Terrarium
There’s no set schedule for watering open terrariums. Instead, learn to spot visual cues that signal when your plants need a drink:
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The top inch of soil feels dry and crumbly. Stick your finger into the soil to check moisture levels.
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Plants appear slightly droopy, wrinkled, or limp. Many succulents show signs of thirst.
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You notice faded, dull leaf colors compared to the normal vivid greens.
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Leaves feel thinner and more pliable than usual. Healthy succulent leaves should be full.
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Growth has slowed or stopped. Lack of new leaves or flowers may indicate underwatering.
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Condensation inside the container has disappeared. Open terrariums still generate some humidity.
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It’s been 3-6 weeks since the last thorough watering. This varies based on climate, plant types, and other factors.
How Often to Water an Open Terrarium
On average, water your open terrarium every 3-6 weeks. But frequency depends on your climate, plant choices, sunlight, and more.
During warm or dry seasons, water as often as once a week. In cool or humid times, wait 6-8 weeks between waterings. Monitor soil moisture and plants to determine the best schedule.
Newly planted terrariums need more frequent watering as roots establish. Mature roots better absorb water from dry soil. Also, terrariums with more succulents and cacti dry out faster than those with tropicals and ferns.
Watering Technique for Open Terrariums
Follow these steps when it’s time to water your open terrarium:
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Use room temperature filtered or distilled water. Cold water can shock roots.
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Water in the morning so excess moisture can evaporate by night.
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Remove the lid and set it aside. Never add water with the lid on.
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Use a spray bottle to gently mist the soil surface. Avoid hitting leaves.
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Spray until water seeps through the drainage layer. This ensures it reaches roots.
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Target visibly dry areas or thirsty plants with extra sprays as needed.
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After watering, replace the lid on the open terrarium.
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Dump out any water pooled in the lid to prevent sogginess.
How Much Water Does an Open Terrarium Need?
When watering, moisten the soil without causing excess saturation. Signs of overwatering include:
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Standing water in the terrarium bottom
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Water pouring from the drainage holes
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Wet droplets on plant leaves
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Very soggy, muddy soil
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Condensation lingering over 12 hours
Soak up extra moisture with a paper towel if needed. Reduce the water amount at the next watering.
Helpful Watering Tips
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In dry climates, place the terrarium on a pebble tray filled with water to increase humidity.
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Group plants with similar watering needs. Mixing thirsty and drought-tolerant plants makes consistency harder.
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Add a thin gravel layer as a topdressing to help retain soil moisture.
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Use terrarium-safe mulch like moss or pine needles to reduce evaporation.
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During droughts, mist 1-2 times a week to supplement sparse watering.
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Always inspect each plant after watering to ensure their needs are met.
Common Open Terrarium Watering Problems
Underwatering
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Plants decline slowly; leaves wrinkle or drop; growth stalls.
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Solution: Water more often when soil dries out. Group plants by water needs.
Overwatering
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Mushy leaves; mold or fungus; rotten roots; yellow, dying plants.
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Solution: Allow soil to dry between waterings. Add a drainage layer. Remove excess water.
Inconsistent Watering
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Some plants thrive while others struggle; unstable growth.
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Solution: Monitor and meet each plant’s preferences. Group plants with similar needs.
Mineral Buildup
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White crusty deposits on soil or container walls.
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Solution: Use distilled or rain water. Add fresh soil annually.
Enjoy Your Thriving Open Terrarium
Follow these tips to determine when and how to water your open terrarium properly. Pay attention to signs of thirst and stick to a routine suited for your climate and plants.
With an appropriate watering regimen, plus attentive care, your mini garden will impress with lush, vibrant plants. Avoid overwatering, as too much moisture causes problems. Find the perfect balance through observation and adjustments. Soon, your sun-loving varieties will be thriving on display.
Where to position a terrarium[image id=”97355″ size=”landscape_thumbnail” align=”none” title=”How to look after a terrarium – where to position your terrarium” alt=”How to look after a terrarium – where to position your terrarium” classes=””] How to look after a terrarium – where to position your terrarium
Closed terrariums
Place these away from windows or in a spot with bright, indirect light as most problems come from too much light or heat. Sit it 1m from a north-facing window, 3m from an east or west-facing window and 5m from a south-facing one.
Open terrariums
Place on a windowsill or table in full or partial sun. If succulents become tall and straggly, they will need more light, so move them to a brighter spot. If they get enough light, they may even produce flowers.
How to water a terrarium[image id=”97353″ size=”landscape_thumbnail” align=”none” title=”How to look after a terrarium – watering terrarium plants” alt=”How to look after a terrarium – watering terrarium plants” classes=””] How to look after a terrarium – watering
Open terrariums
Water succulents and cacti weekly from March to October with a dessertspoon of water per plant. During winter water only every six weeks.
Closed terrariums
You should be able to see condensation up to a third of the height of the jar. If you can, you don’t need to do anything – the terrarium will maintain an even level of humidity and become ‘self watering’. If the condensation line is higher than a third of the way of the jar, remove excess water by opening up and carefully wiping the inside using kitchen roll wrapped around long tweezers. If there’s very little condensation, add a tablespoon of water.
How To Water a Terrarium – EVERYTHING You Need to Know!
FAQ
How often do I water an open terrarium?
How often do you have to water a terrarium? If closed, you might be watering them (on average) once a month but this will vary depending on a variety of factors. Open terrariums benefit from being watered every 3-6 weeks. Rather than watering on a schedule, check the soil to see if and how much water your plants need.
How to tell if your terrarium needs watering?
Dry Moss: Moss is another great indicator. If your moss is dry or crispy to the touch, this is a sure sign that your terrarium lacks sufficient water.
How do you care for an open terrarium?
- Ideal Conditions: Open terrariums thrive in bright, indirect light. Direct sunlight can be too intense, leading to overheating and sunburn for the plants inside.
- Placement: Place your terrarium near a window that receives plenty of light but is shielded from direct sun rays.
How often should I spray my open terrarium?
Tropical Open-Style Terrariums
Watering: Use a spray bottle to water your plants once a week. Apply 10–15 sprays (not mist) per plant. Hot Weather Care: In warm or dry conditions, your terrarium may need extra watering. If the plants appear dry, spray water more than once a week.