We talked with a terrarium expert (really!) to get the best tips for building a gorgeous garden in a glass.

Winter can be a tough time for nature lovers. If the cold is keeping you out of your garden, crafting a terrarium might tide you over. The tiny ecosystems can reconnect you with nature and give you a way to flex your creativity during the dark, cold months. 

Not sure where to start? We talked with terrarium expert Amy Aiello, owner of Portland, Oregon-based terrarium supply store Artemisia, where Amy teaches terrarium-building courses, and co-author of how-to book Terrarium Craft, about all that goes into making these little gardens in a glass. Here are her six tips for building a beautiful, long-lasting terrarium that you'll love.

Credit: Photography by Kate Baldwin

Choose sand over soil

Terrariums are small spaces, so you'll want to avoid over-watering. "Sand is the perfect substrate for terrariums because it's fine enough that it holds the water for the roots, but it dries out a little bit quicker than soil does," Amy says. Plus, sand is prettier than soil and comes in many different colors, giving you lots of creative range. Amy likes pouring horizontal layers of two or more sand colors in her terrariums for a multi-toned look.

Pick the right plants for yourself and your space

"Know your own nature," Amy says. "Who are you? Because you're going to be the caretaker of this thing." If you travel a lot or tend to forget to water your plants, a dry terrarium will be much more forgiving, so scoop up all the succulents and cacti. If you're good about watering, you can mix things up with tropicals, which usually need to be watered about once every two weeks. Similarly, consider how much light your plant babies will be getting before you make your selections. If an air plant is covered with fine white hairs, it's adapted for very sunny climates. Greener air plants require less light. "Bright, indirect light is good for everybody but a necessity for the ones that have that white sheen," Amy says. 

Credit: Photography by Kate Baldwin

Add accessories to your pot

Important as plants are to terrariums, other materials—like pebbles, mosses, shells, dried flowers, lichens, crystals, and stones—are what will make yours unique. Amy favors raw materials. "Polished things don't look quite as natural in terrariums," she says. Her go-to is natural pebbles. "You'll see them in almost every terrarium that we make," she says. "They add dimension and texture." Amy usually puts some around the base of plants to create a transition zone between the bulk of the plant and the fineness of sand. She's not a strict natural-things-only terrarium builder, though. She often sprinkles a pinch of glitter over her little landscapes to "bring the whole thing to life."

Leave some breathing room

It's easy to go overboard when faced with a buffet of dried flowers, glitter, and crystals, but try to summon a little restraint. "I find that leaving a space in the terrarium where there's really nothing happening, where your eye can just rest, is important," Amy says. "You don't have to fill every single space."

Credit: Photography by Kate Baldwin

Embrace the element of chance

Sometimes people get obsessive about their terrariums looking just so, Amy says. She urges them to embrace chance for a more natural look. She likens placing pebbles in terrariums to planting bulbs in your yard. "If you take a handful of bulbs and you toss them into the spot where you want to plant them, they all land where they're going to land. When they come up next year, they're going to look like nature put them there," Amy says. She finds that when she lets pebbles land naturally in a terrarium, the results are often far better than she gets with careful placement.

Your terrarium is you

Aiello has seen hundreds of people design terrariums, and has noticed that the finished product reflects the individual personality. "Each person creates a different design," she says. "Some people are very Zen, it's a very quiet place. Other people, it's vivacious and colorful and vibrant." Each person brings something different to their terrarium—and that's the beauty of it. 

Want more of Amy's tips? Check out her book Terrarium Craft for 50 terrarium designs with step-by-step directions on how to make them!