Boston fern (Nephrolepis exaltata 'Bostoniensis') is a classic hanging-basket fern with arching fronds. University of Wisconsin Horticulture Extension says it is the most drought-tolerant of the commonly grown ferns, hardy outdoors only in USDA zones 9 to 11, and prefers humid air. Brown frond tips are the most common complaint indoors.
Boston Fern at a glance
| Type | Houseplant |
|---|---|
| Season | Perennial |
| Sun | Bright indirect light |
| Plant spacing | 0 in |
| Row spacing | 0 in |
| Per square foot | 1 |
| Seed depth | At surface |
| Days to maturity | Repot or divide every few years in spring |
| How to start | Repot and divide every few years in spring. |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant Boston fern
Repot and divide every few years in spring. Bring plants indoors or protect them when temperatures drop into the low 40s°F. Check your frost dates for outdoor summer use.
How to plant Boston fern
- Give medium-bright light, such as an east window, or a south or west window with a sheer curtain or out of direct sun.
- Use a well-drained mix that holds moisture, such as peat and vermiculite. Hanging baskets and raised containers suit it.
- Keep temperatures right: nights around 65°F and daytime highs at or below 95°F.
Caring for Boston fern
Keep the mix evenly moist but not soggy; see the garden watering calculator and the overwatering checker. Dry indoor air, especially in winter, can brown the tips and edges of the leaflets; double potting inside a larger container lined with moist sphagnum moss helps hold humidity.
During active growth feed every 4 to 6 weeks with a half-strength liquid or slow-release houseplant fertilizer, and cut back sharply in winter. Excess fertilizer browns and dries the frond tips. To encourage new growth, cut old fronds off at the soil line.
Companion plants
| Grow nearby | Other shade-loving houseplants such as pothos |
|---|---|
| Keep apart | Hot, dry rooms and drafts |
Boston fern is a good hanging-basket partner for brighter, humid spots such as bathrooms. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Brown frond tips | Tips and edges of leaflets turning brown and dry | Caused by dry air or over-fertilizing. Raise humidity and cut back feeding. See the yellow leaf identifier. |
| Scale and mealybugs | Bumps or cottony masses on fronds | Boston fern has few pests, but these can occur indoors. For scale, cutting off the affected fronds is the easiest fix. See the pest identifier. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Boston fern is grown for its foliage. To make more plants, divide the root ball vertically into halves or quarters with a sharp knife in spring, keeping as many leaves as possible on each section.
Plan your Boston fern
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant Boston ferns?
Space Boston ferns 0 inches apart in rows 0 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant Boston fern plants?
Pot Boston fern in a well-drained, moisture-holding mix and repot or divide every few years in spring.
How long do Boston ferns take to grow?
Repot or divide every few years in spring; feed every 4 to 6 weeks while growing.
How much water do Boston ferns need?
About 1 inch of water a week, from rain and watering combined. Keep the mix evenly moist but not soggy; humid air matters as much as watering.
Why are my Boston fern tips brown?
Dry air, especially in winter, or too much fertilizer.
How much light does Boston fern need?
Medium-bright light; avoid strong direct sun.
Can Boston fern live outdoors?
Only year-round in USDA zones 9 to 11; protect it when temperatures drop into the low 40s°F.