How Fast Do Pteris Ferns Grow?

Growth Rate

• A specific growth rate can’t be given for Pteris ferns, or for any other ferns, because growth rates vary depending on growing conditions such as the type of soil, amount of water, lighting and temperature. However, generally speaking, slow-growing ferns grow less than 3 inches per year, while ferns with a medium or moderate growth rate grow between 3 and 6 inches. Fast-growing ferns are defined as those that grow more than 6 inches per year.

Light

• For best growth, Pteris ferns need at least four hours of direct sunlight or bright, indirect light every day between September and March. Place ferns about 4 to 8 feet away from the window. Keep ferns out of direct sun between April and August and provide them with about 70 percent shade.

Temperature

• Ferns grow fastest when daytime temperatures are between 73 and 86 degrees F and night temperatures are around 63 degrees. Many Pteris ferns are tropical or subtropical plants, but they still prefer cooler temperatures. That’s because their natural growing environment is under a dense tree canopy where it’s not so hot.

Water/Fertilizer

• Pteris ferns should be kept moist all the times during the growing season; they will wilt if they dry out. How often you’ll need to water them depends on the size of the individual fern, the potting media, temperature and light. Check soil moisture by inserting your finger into it. The water you use should be room temperature to avoid shocking your fern. Add water until it runs out of the drain holes in the bottom, then pour excess water out of the tray so your fern isn’t sitting in it.

  Pteris ferns should be fertilized once a month with a regular fish emulsion. Fish emulsion fertilizer is a mild, organic fertilizer that doesn’t contain salts that might burn delicate fronds. Fertilizer should be applied between April and August.

Potting

• Ferns do best in a well-drained potting mix that contains a lot of organic material. Plant Pteris ferns in a mixture containing one third potting soil, one third peat moss and one third sand-gravel or sand-charcoal. Most ferns have shallow root systems and should be grown in shallow pots that only have about one extra inch of room for additional growth. Depending on an individual fern’s growth rate, your fern may need to be repotted several times a year. Don’t place small ferns in large pots because they will have more problems with excess moisture. Repot ferns when they look like they’re getting ready to spill out of their pot.