Tsusina Holly Fern
The semi-evergreen TsusinaFern is a woodland which makes an ideal houseplant for a cool environment. The delicately-cut fronds are held upright on erect rhizomes, making this a compact and attractive fern for either a fern basket or dish garden, where the fronds can ‘fountain’ upwards. This tough Asian Fem would also be happy in the cold, but dry, environment of an alpine house; it is even tolerant of cold draughts, except when it is in active growth, and is an ideal ground-cover plant to grow below the staging in an ornamental glasshouse. The ends of the dull green fronds bear the sharp spines which give this plant the common name of Tsusina Holly Fern.
This fern is very tolerant of cool growing conditions and will tolerate temperatures to 7°C (45°F). The preferred range is 10-22°C (50-72°F) and plenty of draught-free ventilation is necessary when temperatures are in excess of 21°C (70°F).
The Tsusina Holly Fern should be grown in conditions of poor light.
Steps should also be taken to reduce any glare or reflected light from light-coloured surfaces. Keep this plant barely moist at all times; this species is more tolerant of drought conditions than other Polystichum.
This tough plant is tolerant of minimal levels of humidity. No extra measures need be taken to increase the humidity level.
Feed established plants with a half-strength feed every week during the growing period.
Grow the Tsusina Holly . Fern in a free-drainingthat is rich in . The addition of some chopped moss to a loam-based compost will help the compost retain moisture while also being free-draining. If necessary, repot the plant in Spring.
Use this tolerant, cool- temperature fern in a mixed bowl planting with Spring-flowering bulbs such as Snowdrops or Crocus. The Tsusina Holly Fern will give height and shape to the display.
Insecticides: Ferns are susceptible to insecticides: use systemic insecticides only as a last resort.
Scale is a common problem which can be mistaken for the regularly-spaced brown spores which also cluster on the undersides of the fronds. Irregularly-scattered brown dots of Scale should be removed with a cotton bud and methylated spirit; cut off and burn badly-infested fronds.
Cultural problems: Fronds that turn yellow from the base indicate that conditions are too hot; crisp ends to the fronds are caused by excessively dry air and a lack of humidity, but should not be encountered on this tolerant fern; scorch marks appear on the fronds when the plant is grown in excessively strong light.