TerraGlass
The Journal
How to Layer a Terrarium: Drainage, Substrate, and Moss
A practical walkthrough of the four-layer stack that makes a planted terrarium work — drainage, charcoal, substrate, and top dressing — and why the order matters.
Open vs Closed Terrariums: Which One Should You Build?
The practical differences between an open and a closed terrarium — humidity, watering, plant choice, and maintenance — and how to decide which suits your space.
Choosing the Right Moss for Your Terrarium
A guide to the mosses commonly used in terrariums — cushion moss, sheet moss, and java moss — and how their growth habits should shape your choice.
Ferns for Terrariums: The Best Varieties for Beginners
A rundown of beginner-friendly terrarium ferns — Boston fern, maidenhair fern, bird's nest fern, and table fern — and what makes each one suited to life under glass.
Air Plants 101: Caring for Tillandsia Without Soil
How Tillandsia air plants actually get their water and light without soil, and the watering, placement, and terrarium habits that keep them healthy.
How Much to Water a Closed Terrarium (and How Often)
Reading the signs of a well-balanced closed terrarium — condensation patterns, substrate moisture, and how to correct a jar that's too wet or too dry.
Picking the Right Jar or Vessel for Your Terrarium
How to choose between a cylinder jar, a glass globe, a bell jar, and a rectangular tank based on your plants, your space, and how much you'll need to reach inside.
How Much Substrate (and Drainage Material) a Terrarium Actually Needs
A step-by-step worked example — from a jar's raw volume down to exactly how much substrate and drainage material to buy — using this site's own volume, layer-ratio, and drainage calculators.
The Drainage-Layer Debate: Does a Gravel Bottom Actually Drain?
The classic gravel-under-substrate layer is standard terrarium advice, but the mechanism behind it is genuinely debated. A worked example, and an honest look at what the layer does and doesn't do.
Choosing Plants for an Open or Closed Terrarium (Including Which Are Pet-Safe)
Matching plants to vessel type, worked plant counts for a real container, and a plain-language rundown of which common terrarium and houseplant options are toxic to cats, dogs, or small children.
Establishing Moss Coverage: Fragments, Fill-In Time, and Sourcing It Right
A worked comparison of full-sheet versus fragmented moss planting — how many pieces, how long the gaps take to close, and how sensitive that timeline is to growth rate and coverage.
Plant Spacing for Growth, Not Day-One Looks
The most common terrarium overcrowding mistake is planting to fit a specimen's small nursery-pot size rather than its mature spread. A worked comparison shows exactly how much that gap matters.