Boston ferns are popular houseplants for a good reason - their attractive fronds add texture to any room and they're easy to care for. But is it possible to grow Boston ferns outdoors, too?
The short answer is yes. You certainly can grow Boston ferns outdoors, as well as grow them as one of the best ferns to grow indoors. Of course, these beautiful plants will only thrive in certain climates, but there's no denying incorporating Boston ferns in your outdoor landscape can soften your planting.
Even if you already know how to care for a Boston fern as a houseplant, you need to be aware of the growing environment they require outdoors. That's why I've put together the ultimate guide for you to grow Boston ferns outdoors with success.
How to grow Boston ferns outdoors
The first thing you need to know before trying to grow Boston ferns outdoors is the US hardiness zone of these plants - the regions where these ferns will thrive in an outdoor environment.
'Boston ferns are hardy down to about US hardiness zone nine. But this doesn't mean that they prefer this,' says Raffaele Di Lallo, plant expert from Ohio Tropics. 'The foliage will be damaged by frost, but the plant itself will not completely die if kept in zone nine or warmer. These are mainly native to humid forests throughout South America and Mexico, so their foliage will best be maintained if you keep minimum temperatures above 40°F or so,' he explains.
How to grow Boston ferns outdoors
- Position: It's no secret that ferns are among the best shade plants, so you can get away with placing your Boston fern somewhere hidden from the sun. 'Boston ferns are best grown either in full shade, or partial sun outdoors. Avoid locations with harsh mid-day sun which can potentially cause leaf scorch, particularly if you live in a climate that is hot and dry,' advises Raffaele. Too little light, however, can cause stunted growth and yellowing foliage. To protect these plants from frost, it's also wise to plant them in containers so you can move them somewhere sheltered.
- Water: As with other ferns, it's important to not let your outdoor Boston fern dry out. 'Boston ferns like humidity and slight dampness. Water them regularly, especially if it’s hot out, keeping the soil moist but not soggy,' advises Marek Bowers, garden expert and founder of Bolder Green. 'Mist the leaves once a week, especially if you’re in a dry area - this will keep their fronds from drying out and stop your fern turning brown.' Use this soil moisture meter from Amazon to monitor moisture levels and identify when it's time to water your plants. You can also use similar methods to increase humidity for houseplants to boost humidity levels for your outdoor Boston fern. Try using this plant mister from Walmart, for example.
- Overwintering: As mentioned, Boston ferns are not tolerant to frost and require some protection from harsh weather. Luckily, it's fairly straightforward to overwinter a Boston fern. 'To overwinter Boston ferns, you should bring them indoors before the first frost,' advises Tammy Sons, horticulturist and CEO of TN Nurseries. You should also reduce watering and avoid fertilizing mistakes by not feeding your Boston fern during its dormant season. You should then care for Boston ferns as you would when they're houseplants, placing them somewhere with plenty of bright, indirect light. 'You should do this when temperatures start to dip below 50°F,' notes Marek. Like preventing pests when you bring houseplants back indoors, make sure to isolate your Boston fern. 'Place your fern in a location where you don't have any other plants nearby so that pests don't spread if they are present,' Raffaele explains.
FAQs
When should you prune Boston ferns?
It's best to prune your Boston fern just before its active growth season in spring. This will encourage new, bushier growth for your fern. Use essential pruning tools, like these pruning shears from Amazon, to cut back fronds at the base. You can, of course, also prune away any damaged foliage throughout the year to keep your Boston fern in a healthy condition.
There are lots of other ferns for shade you can pair with outdoor Boston ferns. If you love the look of these ferns in particular and want more of them in your yard, try propagating your Boston fern.
