Last summer I planted six Christmas ferns in my shade garden. The soil is sandy and there is only dappled light in the bed where they are. They looked lush and healthy all summer and stayed green well into the fall. I pruned them back (all the fronds were brown) to about one inch early in May. Now it is the third week of May and – although everything else nearby (Lilies of the Valley, Solomon’s Seal, etc.) has been up for weeks – the Christmas ferns are doing absolutely nothing. Shouldn’t little fiddleheads be appearing by now?? Did our particularly harsh winter kill them? I’ve been watering them for 10 minutes with the sprinkler hose once a week if there is no rain, and I added a bit of compost around each plant today. (Nb., I took the attached picture soon after adding compost and watering.)
I love the look of ferns and some are finicky, but most are relatively adaptable. The Christmas fern (Polystichum acrostichoides), is an evergreen fern with glossy dark green leaves that remain over winter. It is usually adaptable to most conditions. Most ferns prefer humusy and well drained soil and this fern is no different. It also prefers partial sun to shade conditions. Rarely, they can be susceptible to crown rot in poorly drained soils.
So, even though this fern is hardy to zone 3, the early freeze up and prolonged cold winter can kill them, especially if they hadn’t time to take up enough water to prepare for the harsh conditions we experienced this past year in Toronto & Southern Ontario. As newly planted ferns, this could be the issue. Even though your other spring plants are putting forth, give the ferns a bit more time to see if they recover. If they don’t, you may have to replace them, making sure you add plenty of compost or sheep manure when planting and then regular watering while they become established. It is often recommended to water new plants regularly over two years to allow them strong root establishment.
For more information about the Christmas fern: https://www.finegardening.com/christmas-fern-polystichum-acrostichoides