The foxtail fern growth rate is fast when your plant gets steady moisture. UF IFAS rates these plants as fast growers in moist conditions. Yes, your foxtail fern grow fast compared to most ornamental ferns and common garden plants. A healthy plant in good conditions can double its size in a single growing season. Take away the water though, and that speed drops to almost nothing.
In my experience, water makes or breaks your growth speed. I planted two divisions from the same parent plant at the same time last spring. One went into a bed with drip irrigation. The other went into a dry corner where I watered by hand when I got around to it. By the end of summer, my irrigated plant had tripled in size with thick plumes. The dry-corner plant barely grew at all and put out thin, sparse stems. Same genetics, same soil, same sun. Water was the only difference.
Four main factors control your foxtail fern growth speed from most to least impact. Moisture comes first since UF IFAS confirms growth slows in dry spots. Light ranks second because your plant makes more energy in brighter conditions. The ideal temp range is 65-80°F (18-27°C) for the fastest new stems. Fertilizer comes last and gives your plant extra fuel during the active growing season from spring through early fall.
UW-Madison data adds a twist to how light affects your growth. Sun-grown foxtail ferns produce compact, dense plumes. Shade-grown plants stretch out with longer stems instead. Both grow at a similar rate, but the shade plant looks like it grew faster because each stem reaches further out. Your sun plant puts that same energy into filling out with tighter clusters close to the center of the plant.
If you want to know how fast foxtail fern grow from seed versus a division, the gap is huge. Your seedlings take 2 to 3 years to reach mature size because they build their tuberous root system from scratch. Divisions skip that phase since they start with roots packed full of stored energy. A large division planted in spring can fill out into a full, impressive plant by the end of that same summer for you.
The single best thing you can do for faster growth is water your plant on a steady schedule. Deep soaking once or twice per week during the growing season keeps your foxtail fern pushing new stems at top speed. Add a monthly dose of balanced fertilizer from spring through early fall for even more growth. But don't skip the watering and expect fertilizer alone to work. Water is what drives everything else in your foxtail fern's growth cycle.
Read the full article: Foxtail Fern Guide: Care and Cultivars
