How to Grow Fern Indoors

Pick a pot slightly larger than the fern’s root mass.

You’ll want a plastic or clay pot with a drainage hole at the bottom. Ideally, your fern should have about 1 in (2.5 cm) of extra space. Measure your fern’s root mass and pick a pot just a little bit bigger than that. You’ll need to size up your pots as your fern gets bigger, so plan on making a few purchases over time. While it’s often thought that a larger pot will give room for a small plant to grow, that’s actually not the case. Planting your fern in a pot that’s too large can cause the roots to get waterlogged. If you find a pot that you love but it doesn’t have a drainage hole, use a drill with a masonry bit to make a hole dead center in the bottom of the pot.

Fill the pot with organic soil containing peat moss.

Look for a light, well-draining potting soil. Make sure it’s heavy on the peat moss, since that’s what will give your ferns a lot of nutrients. You can find great potting soil at most garden supply stores. Ferns don’t need a ton of extra maintenance, so there’s no need to mix in compost or fertilizer before potting. Floor-growing ferns like to be planted in peat moss-rich mixture.

Water your fern when the top of the soil is dry.

Different fern species have different water needs. Most need to stay consistently moist to grow well. A good rule of thumb is to feel the soil before watering: if the soil is dry, it needs more water. If the soil is still wet, don’t water it just yet. Boston Ferns need water whenever the soil gets dry, while Maidenhair and Button Ferns need to be watered every day. If you aren’t sure about your fern type, try looking up the specific species you have. Consider using distilled water to care for your ferns if your tap water is naturally hard.

Keep the temperature between 60 and 72 °F (16 and 22 °C).

Ferns prefer moderate temperatures that don’t fluctuate often. During the day time, try to keep your home around 72 °F (22 °C). At night, you can turn the temperature down to as low as 60 °F (16 °C). If your home is consistently on the warmer side, you may need to water your fern more often.

Use a humidifier to keep the humidity above 50%.

Ferns are tropical plants, so they prefer high humidity. Set up a humidifier near your fern so it can get the moisture that it needs throughout the day. You can also add moisture to your ferns by placing the pots in a tray filled with gravel. Pour about ⁄4 in (0.64 cm) of water into the tray and refill it whenever it dries out. You could also keep your fern in a room with plenty of running water, like a bathroom or kitchen.

Place the fern in an east-facing window.

Direct sunlight can dry out your fern. An ideal spot for your fern is near an east-facing window; if that’s not an option, you can place it a few feet away from a west- or south-facing window instead. If you notice the leaves on your fern turning brown or dying, they might be getting too much sun. You can filter the light from your windows with blinds, curtains, or outdoor foliage. In general, bright indirect to medium light is best for your fern.

Fertilize your fern during the winter.

Use a liquid houseplant fertilizer to encourage winter growth. Take a look at the bottle to see what the dosage recommendation is, then use about half of that amount. During the fall, summer, and spring, ferns don’t need to be fertilized. If you’ve planted or repotted your fern within the last 6 months, don’t fertilize it just yet. When in doubt, go easy on the fertilizer. Adding too much can kill your ferns.

Spray pests off your fern with water.

Scale, mealybugs, and spider mites are common fern pests. If you notice them, you can either pick them off by hand or blast the leaves with some water to remove them. If the pests are still a problem, try dipping a cotton swab in rubbing alcohol, then carefully wiping down the leaves of your fern. If you notice fungus or fungal mites on the base of your plant, you might be watering your fern too much. Waterlogged roots can cause rot, which attracts fungus and fungal pests.

Divide and repot your fern every 2 or 3 years.

Your fern will outgrow its original pot that you planted it in. When you notice that growth has stopped, carefully uproot your fern and use a sharp knife to divide the root mass into 2 or 3 bundles. Give each bundle its own pot, picking one that’s about 1 in (2.5 cm) larger than the root mass. You can also transplant your fern outside once it gets too large for its pot.