Because Boston ferns are tropical plants, they cannot tolerate freezing temperatures. The best frond growth occurs when daytime temperatures are around 65 degrees Fahrenheit and night temperatures do not drop below 55°F. The lowest minimum temperatures for USDA Zone 10 are 30 to 35 degrees Fahrenheit. Boston ferns die if exposed to lower temperatures.
The best indoor temperature range for these voluptuous plants is between 68 and 78° F, says Colorado State University Extension. Outdoors, plants can withstand considerably higher temperatures as long as you grow them in the shade and give them enough water. Boston ferns thrive in temperatures in their 60s and 70s, but can tolerate an occasional burst of cold air of 40 to 50 degrees for a few hours. Once a month in spring and summer, feed them with a water-soluble fertilizer for indoor plants.
In spring, large plants can be easily divided and transplanted. That's why you grow ferns in your garden. But how cold can they tolerate? In that case, your choice is to move the pot indoors, cover it outdoors, or let the fern die and replace it next year with a hardy fern. Most tropical ferns are not cold-hardy below USDA Zone 10, which has average high low temperatures of just above freezing.
Ferns belong to a large division of plants, Pteridophyta, which includes more than 9,000 species of ferns, according to the Encyclopedia Britannica. The sensitivity to cold of Boston fern hinders its healthy growth and proper formation of leaves, because this plant is simply not adapted to sudden drops in temperature. Whether you move a Boston fern outdoors when summer comes or you grow these ferns outdoors all year round, caring for them is much simpler than if you grow them as indoor plants. The daytime temperatures of 75° Fahrenheit that gradually drop to 65° Fahrenheit during the night are ideal for the Boston fern.
In general, ferns that can tolerate temperatures close to freezing and below are classified as hardy ferns, while those that cannot be called tropical ferns. UU. Zone 9 experiences low temperatures of 20° to 30° Fahrenheit (-7° to -1° Celsius), and most Zone 9 and 10 states are located along the southern and deep south coasts. The winter care of Boston fern in the dormant state does not include the supply of light; a dark place is fine for the plant in the sleep stage.
It is essential that room humidity is maintained between 45% and 60% and that the temperature remains cool between 65° and 72° Fahrenheit (18° to 22° Celsius), although the ideal temperature will differ between fern species. Ferns that grow in warm tropical climates typically need temperatures between 60° and 75° Fahrenheit (15° to 24° Celsius) to thrive, but can tolerate gradual temperature changes between 20° and 95° Fahrenheit (-7° to 35° Celsius). In USDA hardiness zones 8b through 11, it is possible to provide outdoor winter care for Boston fern. It would be better if you place your fern in a room with moderate ambient light and away from cold drafts and breezes.
It is these leaves, which attractively cover the edges of the pots, that make ferns an excellent choice for potted plants, whether they are sitting on patio tables or hanging on the eaves. The plant still needs to be watered thoroughly, but only limited humidity is needed for dormant Boston fern, such as once a month. Although the Boston fern (Nephrolepis exaltata 'Bostoniensis'), also called the sword fern, is commonly referred to as a houseplant, it can grow outdoors year-round in U.
