Fern Care Tips

Types of Fern:

Kimberly Fern: 24" x 24"
Macho Fern: 36" x 24"

Foxtail Fern: 2' x 2-3'
Japanese Painted Fern: 18-24" x 18-24"

Ferns thrive in bright, indirect light. They benefit from a few hours of gentle morning sunlight or softly filtered light through tree canopies. Avoid exposing them to direct sunlight, as it can scorch their delicate fronds, particularly during the intense heat of summer. Ferns thrive in moist, shady conditions similar to their rainforest habitat. Keep soil consistently damp but not waterlogged, adjusting watering as needed for hanging baskets or pots, which dry out more quickly. Ferns thrive in deep, loose soil enriched with organic matter. Most ferns prefer neutral to slightly acidic soil, with an ideal pH range of 6.0 to 7.0.

When planting keep your soil type in mind if your soil needs to be amended do so. When planting make sure the root ball is above level ground by 2 inches to prevent root rot or fungus.

Fertilizing:

Ferns require minimal fertilizer, especially if the soil is enriched with compost. For garden ferns, fertilize once annually in the spring. Outdoor container ferns can be fertilized in spring and again in midsummer if they appear unhealthy. Avoid fertilizing in the fall, as it may do more harm than good.

Pruning:

Prune evergreen ferns in late winter or early spring, just before new growth begins, to maintain their beauty and health. This timing, typically late February to early March in zone 8b,allows for the clean removal of old fronds without harming emerging shoots. Avoid pruning too early to protect the plant from winter damage, and avoid cutting too late to prevent stunting new growth.

Sprayer Use:

• A pump-up sprayer is recommended.
• Avoid leaving chemicals in the sprayer after use.

Seasonal Adjustments:

• Reduce spraying during hot summer months following chemical instructions.

Watering Systems:

• Avoid overhead watering to minimize fungal leaf issues.
• Use drip irrigation as the best method for watering.

Tip Necrosis

Frond tips may shrivel and brown due to uneven watering or low humidity. While unsightly, this is typically not serious.

Identify: Frond tips start to yellow before turning brown and dry. If left untreated, the entire frond may become affected.

Treatment: Trim crispy frond tips above a node. For underwatered plants, resume proper watering. For overwatered plants, remove damaged foliage, replant in well-draining soil, and repot container plants in a better-draining container before allowing them to dry for a few days. Resume watering afterward.

Damping Off

Damping off is a fungal disease affecting young seedlings, caused by water molds and soil-borne fungi. It can quickly kill entire trays of seedlings, with fern seedlings (prothallus) being especially vulnerable due to their need for warm, humid conditions that promote fungal growth.

Identify: New seedling stems may develop black areas where they touch the soil and appear tapered. As the fungus spreads, stems collapse, and white fuzzy spores cover the soil. If unchecked, it can quickly ruin an entire tray of seedlings. Affected seedlings must be discarded and regrown in clean containers with fresh seed-starting mix.

Treatment: Improve air circulation around seedlings, use fresh seed-starting mix to prevent spores, and thoroughly clean all pots before sowing seeds. Additionally, avoid overcrowding seedlings, ensure proper drainage, and consider using a fungicide if necessary to prevent fungal growth.

Fungal Leaf Spot

Fungal leaf spot thrives in wetter, cooler seasons and may cause slow dieback of heavily affected fronds. However, if only a few fronds are impacted, the plant will survive and produce new growth. Herbaceous ferns will regrow fresh fronds the next season. This condition is usually cosmetic, affecting mainly young or weakened plants not in ideal growing conditions.

Identify: Small brown or black spots will develop on both sides of fern fronds. Unlike the spore-producing sporangia, fungal leaf spots are not raised or evenly distributed on the underside of fronds. As the infection spreads, entire fronds may become covered in brown or black blotches.

Treatment: It’s recommended to remove affected fronds as soon as the disease is identified. Mulching with organic compost or finely shredded arborist chips helps keep developing fronds off the soil and reduces soil splash during watering. Limit overhead watering during cool, damp weather, as this is when fungal leaf spot spores are most active and likely to spread.

Crown and Stump Rot

Identify: The top growth of fronds declines abruptly, and upon closer inspection, issues with the root system and black, rotting areas of the fern crown (where new fronds emerge) are evident. The garden soil may be waterlogged, boggy, or have a foul odor due to insufficient air circulation.

Treatment: Remove the plant and either relocate it or address drainage issues in the garden bed. Replant the fern with the crown (where the fronds emerge) at least an inch above soil level to improve air circulation. Avoid piling mulch around the crown & use drip irrigation or soaker hoses to prevent water from collecting &sitting in the crown.

Fern Scale

Female fern scales, Pinnaspis aspidistrae, produce armor that is flat, oyster- or pear-shaped, light brown, with a paler brown crawler cast skin at the narrow end. Occasionally, the second-stage armor is lighter than the adult armor.

Identify: Infested ferns are most visibly damaged by the presence of male snow-white second-stage armors, which contrast with the dark green foliage. Feeding causes yellow spots on certain fern cultivars and liriope. Males do not feed beyond the second stage of development.

Treatment: Horticultural oils, used according to instructions, control fern scales without harming ferns. Two treatments, two weeks apart, are usually effective. Since ferns are sensitive to pesticides, apply them when the foliage will dry before exposure to direct sunlight.