Water a lemon buttons fern deeply to saturate the soil around its root zone, and water it again when the top 3 inches of soil feels dry to the touch. Although the plant is relatively drought-tolerant, its soil should never become bone-dry.
Feed the fern once every six months using a time-released fertilizer with a balanced ratio, such as 13-13-13 fertilizer. Apply the fertilizer according to the recommendations on the product’s label. Follow fertilization with a deep watering to prevent scorching and to distribute the fertilizer evenly throughout the fern’s root zone.
Treat the fern for slugs if necessary. Slugs are indicated by the holes they chew in foliage and the silvery trails they leave behind. Moist, shady conditions are prime territory for the slimy pests. Apply slug baits as directed on that product’s container label. Alternatively, use diatomaceous earth; it is often effective because it lacerates the slugs’ soft skin, which results in death by dehydration. Apply diatomaceous earth by distributing the gritty powder in a 1/2-inch wide ring around the plant.
Spread a layer of mulch around the plant in spring, and apply a fresh layer in autumn. Mulch such as bark chips keeps roots moist and cool. Limit the mulch layer to 2 to 3 inches thick because deeper mulch may harbor slugs.