Light

Most fern varieties naturally grow on the floor of thick, forested areas so they prefer a bright but indirect light. Given the delicate nature of their leaves, they can easily burn if put in direct sunlight.

Temperature

Ferns should be kept in a temperate environment – they prefer daytime temps between 65-75 degrees, and can have nighttime temps no more than 10 degrees lower (55-65). If the temperature is often above 75 degrees, they will be okay but may require more frequent watering. If temperatures fall below 50 degrees, they risk being cold-shocked which is rarely survivable.

Humidity

This is the trickiest aspect of keeping a fern in Colorado. They require a humid environment in order to keep their foliage from crisping up and falling off. A fern should be kept in humidity levels that are consistently above 60%. There are a few ways to accomplish this:

• Keep your fern in a closed terrarium – This is the easiest way to ensure your fern has optimal temperature and humidity levels.
• Give your fern a humidity tray to sit on – By filling a saucer with washed gravel and a very small amount of water and then setting your potted fern on top, you can create a temporarily humid environment immediately around your fern. When using this method, ensure that the soil is not touching the water through your pot’s drainage hole. The water will have to be refilled about every other day.
• Give your fern a humidifier – A humidifier is a great choice for people who have many plants that prefer a more humid environment than Colorado has to offer. There is a great variety to choose from – small, single-plant serving models, to ones that can raise the humidity of a large room.

Watering

Ferns prefer to stay in moist soil. It is important to maintain a good medium between letting the soil dry out and keeping it wet. The best way to tell if your fern needs to be watered is by sticking your finger into the top layer – if the top 1 1/2 inches are dry, then you should water. As with most houseplants, it is much safer to err on the side of underwatering than overwatering.

Fertilizer

Ferns are very light feeders, so they do not need to be fertilized often. For the best results, feed your fern a balanced houseplant fertilizer once every month starting mid-spring through the summer. It is best to not feed your fern during the fall and winter, as they are most sensitive to over-feeding at this time.

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