Planting ferns

When to plant ferns?

To give your ferns the best chance of recovery, plant them preferably in early spring or autumn, when temperatures are mild. These seasons provide ideal conditions for rooting, as the soil is still sufficiently moist and temperatures are moderate. Avoid planting your ferns during periods of frost or extreme heat, which could jeopardise their recovery.

Where to plant ferns?

Growing naturally in woodlands, ferns primarily require coolness and shade! You can, for instance, plant them at the base of some trees or in the shade of a hedge.

Ferns thrive in cool, even moist, soil, ideally in good humus from woodlands. Osmundas, Matteuccia, or Athyrium will flourish on the banks of a pond, while the Male Fern (Dryopteris filix-mas) tolerates drier conditions. Most ferns prefer slightly acidic soils and will struggle to establish themselves in alkaline conditions. However, Dryopteris affinis, scolopendria, and aspleniums prefer calcareous soils.

Ferns enjoy rich, humus-bearing soils. If your soil is poor, we recommend adding leaf compost at planting time. Adding organic matter will make it a bit richer, lighter, and less dry! You can also add turf to improve water retention, or heather soil if your soil is calcareous.

Some ferns grow well in rockeries or on walls (such as Scolopendria, Asplenium trichomanes, or Polypodies)… or even on the stumps of dead trees! In nature, Polypodium vulgare is sometimes epiphytic and grows directly on the trunks of trees. You can also create an original display by installing ferns on a living wall!

Ferns thrive in woodlands. Here, Dryopteris wallichiana (photo Forest and Kim Starr).

How to plant ferns?

In the ground, in the garden:

• Before planting, thoroughly moisten the root ball of your fern by soaking it in a basin of water for about fifteen minutes. This will allow the roots to absorb the water they need to establish well.
• Dig a hole twice as wide as the root ball to give the roots enough space. The depth should be equivalent to the height of the root ball.
• Replace a bit of soil mixed with leaf compost at the bottom of the hole. You can also add a little heather soil to slightly acidify the mix, as ferns prefer humus-bearing and slightly acidic soil.
• Position the root ball in the centre of the hole, ensuring that the top of the root ball is level with the soil, neither too deep nor too high.
• Replace the soil around the fern, filling in the sides well. Lightly compact it to avoid air pockets that could dry out the roots.
• Once the fern is planted, water generously to thoroughly moisten the soil all around.
• We recommend mulching around the base of the fern with pine bark, ramial chipped wood (RCW), or even dry fern fronds. This will help retain moisture and limit weed growth.

In a pot:

• Mix universal potting soil with heather soil to create a light, well-draining, and slightly acidic substrate. This mix will allow the fern to thrive in a pot.
• Choose a suitable pot, wide and deep enough to accommodate root growth. Ensure it has drainage holes to prevent excess water.
• Add a layer of gravel, clay pebbles, or broken pot shards at the bottom of the pot to improve drainage. This will prevent the roots from sitting in water, which can cause them to rot.
• Pour a bit of substrate into the bottom of the pot, then position the root ball in the centre, keeping the top of the root ball level with the rim of the pot.
• Fill in with the remaining substrate around the root ball and gently compact it to stabilise the plant.
• After planting, water generously to moisten the substrate.

For optimal maintenance, keep the substrate moist without excess. Place your pot in a shaded or semi-shaded area, as ferns prefer lightly sunny spots.

How to care for them?

After planting, water your ferns regularly to keep the soil moist, especially during the first two years, and particularly during dry spells. Consistent moisture is essential for the proper development of their roots.

Subsequently, your fern will become more self-sufficient and will better tolerate dry periods. In cases of intense drought, it is normal for its foliage to wilt or disappear; it will naturally regrow when moisture returns.

As autumn approaches, gradually reduce watering, as the fern enters dormancy. During this period, overly moist soil can weaken its roots.

In summer, mulch around the base of the fern to keep the soil cool and limit water evaporation. You can use pine bark, dry fern fronds, or even fallen leaves. You can also apply a layer of mulch to protect the stump in winter, in case of severe cold.

Ferns are not very demanding, but they appreciate humus-bearing soil enriched with organic matter. If your soil is poor, make a light application of compost or leaf mould in spring. One addition per year is sufficient to stimulate the growth of the plant.

Ferns are sensitive to being moved; they do not like to be disturbed once well established. Avoid transplanting them, as this could disrupt their growth and adaptation to their environment.