Your ferns should be planted in rich woodland duff – compost, peat, leaf mold – well drained crumbly humus. (Please NO manure and take care not to bury the fern’s crown!) Aside from an annual top dressing of leaves, we do not feed the plants in our garden in the belief that a well prepared site should provide adequate nutrition for a fern to prosper as it would in its natural habitat. The old fronds may be left on to nourish the fern or removed to “tidy up”! In either case they should be left on the plant over the winter for cold protection.
We do feed the nursery stock which in flats and pots tends to deplete available nourishment. Our recommendation is for an application of any evenly balanced fertilizer with trace elements at 1/2 the manufacturer’s recommended strength just before new growth starts (for us this is approximately late March), followed by a light application of an evenly balanced slow release fertilizer again with trace elements and again at 1/2 strength as the weather warms up (late May/early June). As a temperature regulated fertilizer slow release material is NOT recommended for greenhouse use. This is the extent of our feeding program. We firmly believe that an unforced plant is better prepared for the transition from nursery to garden.
Ferns prefer to be planted in filtered shade (not dank hollows) and in general tend to like acid soil as well. Conifer needles and peat make excellent additives to increase acidity. Depending on your climate many ferns will tolerate morning and late afternoon sun, but most need protection from intense mid-day sunshine.
Ferns are not particularly bothered by pests. Slugs will occasionally chain saw tender new growth so bait should be out and about before they start their spring browsing. Ferns are not tolerant of many pesticides and should be protected from general spraying. Oil based sprays are particularly hard on foliage. We prefer to leave the few bugs we have for the birds!
Newly planted ferns should be watered regularly and deeply until they are well established. We prefer not to water when the sun is on the foliage. As ferns mature they become more drought tolerant. (For us they outperform both our rhodies and the lawn!) They also should be winter hardy if you match appropriate plants for your USDA zone. However, if an arctic express is predicted a light mulch (snow is great) can add protection.