How Often Should You Water an Open Terrarium? A Complete Guide

There is no mess and it’s easy to take care of terrariums, also known as bottle gardens. They make little landscapes for houseplants that are both relaxing and healing. They’re easy to make, look perfect on a desk or coffee table and make excellent gifts.

Open terrariums are beautiful, mini indoor gardens that allow your plants to thrive. But caring for an open terrarium requires some finesse, especially when it comes to watering Understand the signs of thirst and techniques for watering open terrariums properly.

What is an Open Terrarium?

An open terrarium is one that doesn’t have a fully enclosed lid or cover This allows for ventilation and airflow Open terrariums house plants that prefer drier conditions, including

  • Succulents
  • Cacti
  • Haworthia
  • Certain ferns
  • Air plants
  • Some tropical foliage

The open design means humidity doesn’t build up. Your arid-loving plants can soak up the sun and avoid sitting in damp soil

Signs It’s Time to Water Your Open Terrarium

There’s no set watering schedule for open terrariums. Instead, learn to read the signs that indicate when your plants need hydration:

  • The top inch of soil feels dry to the touch. Stick your finger in the soil to test moisture levels.

  • Plants look slightly droopy, wrinkled, or limp. Many succulents will show signs of thirst.

  • You notice faded or dull leaf color compared to normal vivid greens.

  • Leaves feel thinner or more pliable than usual. Healthy succulent leaves will be full.

  • Growth has slowed or stopped. Lack of new leaves or flowers can signal underwatering.

  • Condensation inside the container has disappeared. Open terrariums still generate some humidity.

  • 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, most open terrariums need water every 3-6 weeks. But again, this varies based on your climate, plant choices, sunlight exposure, and other factors.

During warm or dry seasons, your open terrarium may need water as often as once a week. In cool or humid times, it may go 6-8 weeks between drinks. Closely monitor soil moisture and plant signs to determine optimal watering frequency.

Newly planted open terrariums need more frequent watering as roots establish. Mature root systems can better absorb water from dry soil. Also, an open terrarium with more succulents and cacti dries out faster than one with ferns and tropical plants.

Watering Technique for Open Terrariums

When it’s time to water your open terrarium, use these techniques:

  • Use room temperature filtered or distilled water. Cold water can shock plant roots.

  • Water early in the day so excess moisture can evaporate by nightfall.

  • Remove the terrarium lid and place it aside. Never add water with the lid on.

  • Use a spray bottle to gently mist over the soil surface. Avoid hitting leaves.

  • Spray until you see water seeping through the drainage layer. This ensures its reaching roots.

  • Add extra sprays to visibly dry areas or over thirsty plants as needed.

  • After watering, place the lid back on the open terrarium.

  • Dump out any water that collected in the lid to keep the interior from getting overly soggy.

How Much Water Does an Open Terrarium Need?

When watering, aim to moisten the soil without causing excess saturation. Signs you’ve added too much water include:

  • Standing water collecting in the bottom of the terrarium.

  • Water pouring out of the drainage holes.

  • Wet droplets remaining on plant leaves.

  • Very soggy soil that looks muddy or feels squishy.

  • Condensation that takes over 12 hours to evaporate.

If you notice these, use a paper towel to soak up extra moisture. And cut back the amount of water you add next time.

Helpful Tips for Watering Open Terrariums

  • In dry climates, consider placing the open terrarium on a pebble tray. Fill the tray with water to increase ambient humidity.

  • Group plants with similar watering needs. Mixing very thirsty and drought-tolerant varieties makes consistency harder.

  • Add a thin layer of small gravel as a top dressing to help retain soil moisture.

  • Use terrarium-safe mulch like moss or pine needles to reduce soil evaporation.

  • During droughts, spraying the terrarium 1-2 times a week helps supplement sparse watering.

  • Always inspect thoroughly and touch base with each plant after watering to be sure their needs are met.

Common Open Terrarium Watering Issues

Underwatering – Plants decline slowly; leaves wrinkle or drop; growth stalls.

Solution: Water more frequently when the soil dries out. Group plants by watering needs.

Overwatering – Mushy leaves; molds or fungus; rotten roots; yellow, dying plants.

Solution: Allow the soil to dry between waterings. Add a drainage layer. Remove excess water.

Inconsistent Watering – Some plants thrive while others struggle; unstable growth.

Solution: Monitor and adapt to meet each plant’s preferences. Group plants with similar needs.

Mineral Buildup – White crusty deposits on soil or terrarium walls.

Solution: Use distilled or rain water. Add a thin layer of fresh soil annually.

Caring for Your Open Terrarium

Aside from watering, these tips will keep your open terrarium healthy:

Sunlight – Place in bright indirect or filtered light suited to the plants inside. Rotate periodically.

Temperature – Avoid drafty areas or hot sun. Most do best at 60-80°F.

Cleaning – Periodically wipe down glass and prune dead leaves/stems to look tidy.

Fertilizer – Use a weak cacti/succulent fertilizer every 3-4 months during the growing season.

Pests – Isolate and treat plants if you notice insect infestations like mealybugs.

Repotting – Replant in fresh soil every 2-3 years as minerals build up over time.

Pruning -Trim leggy growth and spent flowers to encourage bushy plants.

Enjoy Your Thriving Open Terrarium

Now that you know when and how much to water your open terrarium, you can relax and enjoy! Pay attention to signs of thirst and stick to a routine that works for your climate and plants.

With a proper watering regimen, plus attentive care, your mini garden will impress with lush, vibrant plants. Just be sure not to fuss over or overwater your open terrarium, as too much moisture can spell disaster. Find the perfect balance through observation and small adjustments. Soon, you’ll have thriving succulents, air plants, and other sun-loving varieties on display.

How to look after a terrarium

Terrariums are fairly low maintenance and the plants growing inside them will largely look after themselves. Closed jars will create their own ecosystem and even become self-watering. Where you keep your terrarium is very important for the plants’ survival, so before you put different plants together, make sure you know how much light each one needs. Humidity can also be an issue, with some plants requiring dry environments and others needing constant humidity.

In this short video guide, the experts at Grow Tropicals share their tips for caring for terrariums, including what compost to use and what type of container to use. Green Video Post Element Video ID: “ea9831de75bbb23983b99762a3a55f0fb51e5d04” Mix ID: “” Player ID: “qAUyOzk5” If the player doesnt appear here within a few seconds, the Player ID or Licence Key (set via IM Green Video settings) might be invalid.

More on planting terrariums:

Browse our list of terrarium care tips, below.

Where to position a terrarium

how often to water an open terrarium

Closed terrariums

Do not put these near windows or in a place with direct, bright light. Most problems are caused by too much heat or light. If it faces north, put it 1 m away. If it faces east or west, put it 3 m away. And if it faces south, put it 5 m away.

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 – EVERYTHING You Need to Know!


How often do you water an open top terrarium?

In winter we check our cacti and succulent terrariums every 4 weeks, and water them lightly every 4-6 weeks or less. In summer months during it’s growing season, your terrarium will need more water. In the height of summer we check ours weekly, and water lightly every 1-2 weeks.

How do I know if my terrarium has enough water?

If the soil is completely dry and the leaves are wilting this is a sign that the terrarium is too dry and needs watering. NEVER pour water into your terrarium. Water should be added a little at a time using a misting bottle to avoid overwatering as there is nowhere for excess water to go.

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