Starting an Indoor Garden: Light, Humidity, and Other Factors

Starting an indoor garden is an easy way to green up your indoor spaces, but houseplants have also been shown to boost mood, increase productivity, and reduce stress. Many indoor plants like snake plant and spider plant are also low care which means less fussing for you. As with any type of garden it’s important to start with a plan. Below I lay out six considerations to keep in mind as you plan an indoor garden.

6 considerations when starting an indoor garden

Before you head to the plant store or start browsing for pots and plants online, take a few minutes to plan your indoor garden. It can save you time and money, but also help you select the best plants for your indoor growing conditions.

Light

Light is the most important factor to keep in mind when choosing plants for an indoor garden. Don’t select plants based on something you’ve seen in an Instagram post. Instead, pick plants that will thrive in the specific growing conditions of your home. Light can be natural, from a window or skylight, or artificial, from nearby lamps or a grow-light. Start by examining both the amount and type of light you have in your home.

Window direction:

North-facing windows receive little to no direct light, especially in winter.
East-facing windows enjoy morning sun for much of the year with increased light in winter.
South-facing windows offer the most light. They get a lot of winter light from the low winter sun but less in summer when the sun is high overhead.
West-facing windows offer bright afternoon and late day sunshine.

Keep in mind that the amount of light coming through your windows shifts from season to season, but it also depends on decorative elements like window blinds and curtains, as well as outside influences like trees, shrubs, or roof overhangs.

While many plants are tolerant of lower light conditions, that doesn’t mean they’re happy there. If your home doesn’t offer the appropriate level of light for the plants you wish to grow, you can supplement with grow lights. There are many types of grow lights available online and in garden centres. I use grow lights to start seedlings but also to keep my indoor herbs happy. A 12” LED grow light tucked beneath one of my kitchen counters promotes healthy growth of my basil, parsley, rosemary, and cilantro plants, especially in winter. I also use a spotlight type growlight to boost winter light levels for my succulents.

If you’re serious about indoor plants, I’d suggest getting a light meter or a light meter app for your phone to measure the light intensity of the different areas in your home. Matching plants to their preferred light levels is the first step in promoting healthy growth.

Consider light when selecting indoor plants — When picking plants for your home be sure to match them to your light conditions. If your home offers little light, supplement with a grow light.

Humidity

Humidity is the amount of water vapor in the air and can change significantly from season to season. In winter when we have furnaces, fire places, or heat pumps warming our homes, the air is very dry. Many plants prefer a higher humidity than we can offer, but there are a few things indoor gardeners can do to boost humidity levels.

How to boost humidity:

Mist your plants. Using a simple hand mister, give your humidity-loving plants a quick daily spritz.
Cluster plants together. In their natural environment, most plants grow in groups. Re-creating this inside your home not only looks decorative but as the plants transpire, the humidity level increases.
Place plants on trays of pebbles or rocks. Partially fill the tray with water. As the moisture evaporates, it raises humidity levels. Keep the water level about halfway up the sides of the tray. If the water reaches the top, the bottom of the pots may end up sitting in water. This can cause root rot. You may also wish to slip a saucer beneath each pot. This does two things: 1) it prevents excess water from being taken up by the plant and 2) it prevents soil from being washed into the pebble tray each time you water.
Add a humidifier to your home. In winter, I use a humidifier to add moisture to the air. It’s made a big difference to the plants in my indoor garden.
Keep high humidity plants in the bathroom where there is typically more moisture in the air. Air plants and ferns are good choices for a bathroom.

Watering

Learning how and how often to water is essential when starting an indoor garden. Not all plants have the same moisture requirements but it doesn’t take long to get a sense of how much, or how little, water a plant needs.

My first tip is to do a bit of reading about what type of water and light requirements a specific type of plant has before you buy it. Desert plants like cacti need little water but tropical plants which come from hot, humid climates have higher irrigation needs. Another factor in watering is the time of year. Plants grow slower in fall and winter which means they use less water.

Once or twice a week, depending on the season, I do an indoor garden tour where I wander around with my watering can to water where necessary. To gauge soil moisture I use the finger test; I stick my finger into the top inch of soil. If it’s dry, I water. If it’s still damp, I don’t. When watering, saturate the soil to ensure an even application of water. You can also water from the bottom by filling the saucer beneath the pot with water, topping it up until no more water is absorbed. Dump excess water in the saucer once the soil is saturated.

Learn how to water an indoor garden — Overwatering is the quickest way to kill indoor plants. Don’t water on a schedule, instead, learn to water by paying attention to the plant and the soil.

Container selection

It may not seem like a big decision, but pot selection is an important consideration when starting an indoor garden. It’s likely your plants will be in those containers for several years and the right sized pot can help promote healthy root development and growth. The pot should be slightly larger than the size of the rootball. You’ll know it’s time to repot when you see roots emerging from the drainage holes, or when you slip the plant from the pot and the rootball is a mass of tangled roots.

The pot should also offer good drainage. Drainage holes ensure that excess water doesn’t sit in the pot and cause root rot and other issues. If you do fall in love with a pot that doesn’t have drainage – trust me, it happens – you can still use it with success by employing a simple ‘pot in pot’ trick. Place your indoor plant in a smaller plastic pot which can then be placed in your desired pot. When it’s time to water, slip the smaller pot out of the larger container to water. Place it back inside once excess moisture has drained away.

Visit any garden centre and you’ll discover pots in a variety of sizes, shapes, colours, and materials. Terra cotta pots are traditional but because they are porous, they dry out quickly. Ceramic planters are stylish and very popular for houseplants. If they’re glazed they’ll also hold water better than terra cotta. The downside is that they may not have drainage holes. Plastic pots are often cheap, lightweight, and usually come with several drainage holes.

Checking the roots of an indoor plant — Plants can become root bound when they outgrow their pots. It’s a good idea to inspect the roots every year or so to make sure there is still room for them to grow.

Potting mix

A good growing medium supports a plant by anchoring it, providing nutrients, draining away excess moisture, and being light enough to provide air pockets for the roots. The type of growing medium you use depends on the type of plants you’re growing. Common types include all-purpose potting mix, succulent mix, cacti mix, and orchid mix.

If you read the ingredient list on a bag of potting mix you’ll likely spot materials like peat moss, coconut coir, vermiculite, perlite, sand, compost, or bark mulch. Many gardeners prefer peat-free mixes which are becoming easier to source both online and at garden centres.

Fertilizing

Living in the same soil for months or even years can leave the growing medium of your indoor plants depleted of essential nutrients. A regular fertilizer program replaces these nutrients. There are liquid, water soluble powder, and granular fertilizers available. Liquid and water soluble powder products are diluted in water and applied to the soil surface. Granular fertilizers are slower to release, feeding a little bit each time the plant is watered. Expect them to last for three to six months.

When starting an indoor garden it’s important to know that you don’t need to feed your plants year-round. Typically houseplants are fertilized only when they are actively growing in the spring and summer. You don’t want to overfeed your plants. To learn more about both timing and types of houseplant fertilizers, check out this detailed article by Jessica.

When starting an indoor garden look for plants that will thrive in your indoor growing conditions — There are so many types of plants that can be grown as houseplants. Some that are considered less maintenance include snake plants, zz plants, and golden pothos.

Starting an indoor garden: Types of plants to include

Let’s be honest, indoor growing conditions aren’t ideal for most plants. What we call ‘houseplants’ are generally tropical plants from frost-free climates that can be adapted to growing inside our homes. We try to replicate their natural growing conditions so they can thrive indoors. However, not all indoor gardens are collections of houseplants. You can also grow herbs, vegetables, or even fruits like strawberries inside year-round. Learn more about growing an indoor food garden here.

Starting an indoor garden: Sourcing plants

With the popularity of indoor gardening, it’s easy to source houseplants from local garden centres and florists. Or, you can start with a new plant or cutting from the plant of a friend. Many houseplants and herbs are easily grown from cuttings with little money spent. Here are some of the best ways to source plants for your indoor garden:

Garden centres – In spring and summer many garden centres sell indoor plants as well as seedlings, perennials, trees, and shrubs. Come winter, year-round nurseries continue to stock indoor plants as well as soils and supplies. Don’t be shy about asking the knowledgeable staff questions about individual plants to help you access whether they’re a good fit for your home.
Friends and family – Getting a plant, a division, or a cutting from a gardening friend is one of the most cost-effective ways to grow an indoor garden. You may even want to host a plant swap where everyone brings a few pieces of their favorite plants to trade for new-to-them specimens.
Local buy and sell forums or websites – You’ll find local plant forums on social media as well as on buy and sell websites. Connecting with like minded indoor gardeners is a great way to expand your plant collection. You may also find listings for plant giveaways or sales for those who wish to re-home plants when they move or if the plants have outgrown their space.
Florists – Most florists have branched out into indoor plants as well as cut flowers. One of my local florists offers a large collection of air plants, succulents, and easy care tropical plants.
Online – Online plant stores are a convenient way to shop for indoor plants. Look for a reputable supplier with good reviews so you can be confident in the quality of your plants.

A plant shelf is a stylish way to display a houseplant collection. You’ll find many sizes and styles in home stores as well as online.

Starting an indoor garden: 3 ideas for designing the space

A window garden

Once you’ve picked the appropriate plants for its light conditions, it’s time to design your window. You can keep it simple and cluster pots along the sill or you can add additional shelves or brackets to the window for several layers of plants. If you’re growing vining houseplants, you may wish to string wire to support and direct their growth.

Plant shelves and stands

Show off your collection of indoor plants on a stylish shelf or stand. There are many types and sizes available online and in garden or home supply stores. For large gardens a multi layer bookshelf or ladder shelf offers plenty of space, but you can also find single or multi-tier plant stands, corner stands, or narrow stands to add plants to even the smallest areas of your home.

A corner plant shelf is a great spot to tuck a few indoor plants.

Hanging garden

I love hanging pots of succulents, herbs, and other sun-loving plants in my bright kitchen window. Hanging pots, planters, glass or plastic shelves, or macrame holders can be bought or DIY’d. (Check out this easy step-by-step macrame tutorial). I like to buy hanging planters that don’t have drainage holes so there isn’t a flood onto my windowsill or counter when I water. Instead, I tuck a smaller pot – with drainage – in the planter and when it’s time to water I remove the potted plant and give it a thorough watering in my kitchen sink. Once it stops dripping, it goes back in the hanging planter.

Find more fun ways to get started with houseplants in the book Houseplant Party by Lisa Eldred Steinkopf.

For further reading on growing plants indoors, be sure to check out these articles:

Are you starting an indoor garden in your home?