How to Grow and Care for Ostrich Ferns

Ostrich ferns are perennial ferns that produce edible fiddleheads, a springtime delicacy. As they grow, these young sprouts unfurl into bright bunches of 4-foot green fronds looking like ostrich feathers. Ostrich ferns grow best in woodland or understory conditions, preferring dappled or partial sunlight, acidic or neutral humus-rich, moist soil, and cooler temperatures.

Ostrich Fern Care

Here are the main care requirements for growing ostrich fern:

• Plant it in a moist, filtered sun location.
• Transplant into a shallow hole.
• Grows best in acidic soil (5.0 to 6.6).
• Does not need fertilizer; it grows best in naturally fertile or compost-enriched soil.
• Prune new sprouts and divide annually to prevent overspreading.
  

Warning

Once established, ostrich ferns spread rapidly but are not technically listed on state or federal invasive plant lists. Ostrich ferns can become aggressive growers, stifle other species, and overtake an area fairly quickly if not controlled by pruning and division.

Light

This fern grows in partial to full shade, but dappled shade is generally best. Leaves can turn yellow and burn if exposed to full sun. It will tolerate full sun only if planted in an especially cool, moist location.

Soil

The ostrich fern grows best in moist, acidic soil rich in organic matter, but it will tolerate clay soil. The soil pH should be between 5.0 and 6.5. Native to marshes and creekbeds, it tolerates some erosion and a lot of moisture.

Water

Water throughout the summer to maintain medium to wet conditions. Do not let the soil dry out. The plant might go dormant too early in the growing season without enough moisture.

Temperature and Humidity

Native to eastern North America, east Asia, and Europe, the ostrich fern is one of the most common native ferns, hardy in USDA hardiness zones 3 through 7. The plants are hardy to minus four degrees Fahrenheit. The ostrich fern grows best in cool summer climates rather than climates with hot and humid summers. Ensure airflow between plants to prevent fungal issues.

Fertilizer

While it is unnecessary to fertilize an ostrich fern, if you are fertilizing other plants nearby, lightly fertilize them. Do not overfertilize because these ferns are sensitive to too much fertilizer.

The Difference Between Ostrich, Cinnamon, and Interrupted Ferns

Two other types of ferns look similar to the ostrich fern and are commonly mistaken for it: the cinnamon fern (Osmundastrum cinnamomea) and the interrupted fern (Osmunda claytoniana).

The easiest way to tell them apart is by the shape and look of the fronds. Simply turn over a frond to examine it.The cinnamon fern has a furry or hairy spot near the sheath, where the stem and leaf meet, on the frond, and the interrupted fern has forked veins and leaflets that are about three inches long and don't extend down to the ground as the frond leaflets do on an ostrich fern.

Pruning

Heavy pruning isn't needed, but light trimming keeps ostrich ferns looking fresh. Clean up any old or awkwardly shaped fronds. In late winter, cut down dead foliage and fertile fronds.

Propagating Ostrich Ferns

Ostrich ferns are aggressive spreaders. They're bountiful and can take over your garden because they spread through underground rhizomes. The upright, arching, rhizomatous plant can spread 5 to 8 feet wide and, in the wild, can grow up to 6 feet tall in moist, cool climates.

Unlike other ferns that release spores to make new plants, ostrich fern fronds are sterile. Here's how to propagate ferns by regular division each spring to keep them from overspreading:

1. Select a fern that has grown twice the original plant size.
2. Use a shovel to dig around the entire outer perimeter of the fern and remove the fern from the ground.
3. Shake off the excess soil to see the rhizomes, divide them with a spade or sharp knife, or sometimes pull them apart with your hands.
4. Plant the fern divisions in a shady, moist location and water them well.

Potting and Repotting Ostrich Ferns

Though not ideal, ostrich ferns can also be grown in containers. When planted in a container, these ferns make a showy statement on outdoor patios and entryways. Make sure the container is large enough to allow the fern to spread and grow as it matures. Fill the container with rich, acidic soil and water the plant regularly to keep the soil moist. The pot needs ample drainage holes to prevent the soil from getting waterlogged.

Repot the plant when the fern fills the container and becomes rootbound. Divide it, keep one in that pot, and transplant the division into a new pot.

Overwintering

Ostrich ferns are hardy, can handle cold temperatures, and will go dormant in winter. Here's the typical growth cycle and how to handle it for winter:

• In the active growth phase, the plant creates a massive crown of fronds, shaped like a vase, around less showy, spiky, erect, dark brown fronds.
• By early fall, the green outer fronds wilt and become tattered, losing their leaflets entirely (earlier than most ferns).
• By winter, the plant goes dormant. Besides cutting down the dormant fronds, there's not much more you need to do to overwinter these plants. New growth will emerge in the spring.

Common Pests and Plant Disease

Ostrich ferns are not susceptible to serious common pests or diseases. However, if the plant gets waterlogged, it can develop root rot. Also, without sufficient airflow around the plant, ostrich ferns become susceptible to fungal infections. These plants are typically rabbit—and deer-resistant.

Common Problems with Ostrich Fern

Ostrich ferns can easily grow from transplants when their favorite growing conditions are moist, acidic, fertile soil and dappled light. It is relatively problem-free, and deer and rabbits usually leave it alone.

Browning Leaves or Patches

If you notice browning spots on your plant and it's situated in a very sunny place, it's likely to get sunburn or leaf scorch. If the leaves begin to get crispy or curled, they may also need water. Transplant or move the plant to a shadier location, ensuring the soil remains moist.

Yellowing Leaves, Mushy Leaves, or Foul Odor

Root rot is usually caused by giving a plant too much water; yellowing leaves and stems, leaves turning mushy, and a foul, rotten odor are all signs that the plant is likely drowning. Soggy soil is a hospitable place for fungal overgrowth. Prevent this condition by watering on a regular schedule, but only if the soil is drying out. Also, if the plant is being grown in a container, ensure it has well-draining soil and ample drainage holes at the bottom.

From: thespruce