The Boston fern (Nephrolepis exaltata) is a popular fern species that is native to tropical areas like the Americas, Polynesia and Africa, as an understory plant. This attractive fern is a popular choice as a houseplant, due to its low sunlight needs. As a slow growing plant, it thrives best when planted in the fall or the spring, which makes it a great option for the approaching autumn!
In the wild, the Boston fern is an understory plant, growing underneath plants and tree canopies. Thus, it has low sunlight needs, with only 2 – 3 hours of indirect sunlight required a day. In the summer and spring, it does best placed 3 – 5 feet away from a south-facing window to prevent leaf burning. If you see signs of leaf scorch (i.e. browning, shriveled tips), move your plant further away from the window. In fall and winter, classic bright, indirect lighting should be perfect for your Boston fern.
As with all houseplants, water the Boston fern quite literally… when it needs water. The best way to tell if your fern could use a drink is by conducting the 1 ½ inch test; if the top inch or so of soil is dry, it’s time for a watering. If your fern is a mature plant, it may be difficult to touch the soil due to frond (leaf) growth, so you can also just pick up its pot and sense its heaviness. You have to use a bit of discernment here, so this method is useful if you’re familiar with how heavy your pot should be between waterings. Soil moisture meters are also a great tool, and they are very affordable (around $12 from Home Depot).
When it’s time for a watering, water your Boston fern near the crown, giving it a light drink. Ferns can take a while to rehydrate, particularly with peat-blend soil mixtures, so the best method is to give it a light watering, wait a while, and then give it more water. Stop when your plant is moist, but not soggy. Overly wet soil can lead to lethal problems, like root rot.
Tip: When you begin watering your fern, if the water goes straight through to its drainage holes, this does not mean your plant is adequately watered yet! Try the water – wait – water technique.
Boston ferns thrive in higher humidity conditions. There are many ways to increase the humidity surrounding a plant. One option is to keep your fern in a high-humidity region of your home, like a bathroom (providing it has windows). Humidifiers are also useful for this purpose, as is grouping your plants closely together so that they transpire around each other, naturally increasing their humidity. DIY humidity trays are another thrifty option. For a complete list of tips to create plant humidity, check out step 3 of this article
This gorgeous houseplant is happiest in well-draining soil. You can achieve this with a blend of compost and indoor-plant soil mixture, with a bit of coconut coir or sand and perlite. The goal is to create a blend of rich and organic matter, while offering great drainage, so that the soil only retains some water.
From the spring to early fall, fertilize your Boston fern with a half-diluted liquid fertilizer once a month. Don’t fertilize your fern from late fall to winter.