Welcome to the Rock Garden
The Rock Garden was built in 1907, using over 200 tons of sandstone brought in from Penshurst. Abandoned in the 1940s, it was cleared and reopened in 2019. Originally, it had been planted with alpines, but the decision was made to replant with ferns.
Jump to: The Stumpery | By The Pond | The Dell | Towards the Wisteria
The Ferns
We have over 90 varieties of fern in the Rock Garden, and the number is growing, often as a result of gifts from fern enthusiasts who have taken an interest in what we are doing.
What to Look For in……
Spring
This time of year is the season of new growth. Many ferns are deciduous and died back over the winter; others are semi-deciduous and have only recently been cut back:
The new fronds – called croziers, or more informally fiddleheads, because they look like the end of a fiddle - are now appearing. You can see them at various stages as they gradually unfurl.
This is the best time of year for colour, as the new fronds range from the oranges of the Dryopteris erythrosora below the path opposite the pond to the lovely bronzes of the Dryopteris wallichiana by the Stumpery and at the top of the steps.
IMAGES: left - Dryopteris erythrosora , Right - Dryopteris wallichiana
Summer
The ferns are filling out now and the spring colours to mature to a deeper green.
Look for the fluffy flower-like fertile fronds on the Osmunda regalis at the edge of the pond.
They are also showing their true texture. There is a group of random Dryopteris sporelings by the path opposite the Stumpery where you can see some interesting variations in cresting.
IMAGES: left - Fertile frond on an Osmunda regalis , Right - Dryopteris sporelings with different levels of cresting
Autumn
Everything will by now have achieved its full growth; in fact, the early starters are already beginning to turn. This is also the time of year that the reproduction process starts.
If you carefully lift a frond, you will see the mature sporangia, the little containers that contain the spores, on the underside. When ready, they will explode and send the spores into the wind. Not all fronds are fertile, and you may have to lift a few.
Some of the Polystichum at the front of the bed opposite the boat swing produce bulbils (little bulbs), not spores. You’ll see these on the top of the frond.
IMAGES: left - Mature sporangia , Right - Bulbils on a Woodwardia
The Stumpery
This is our take on a stumpery, where we are working to create a showcase for special ferns that need to be seen close-up to be appreciated. It was started at the beginning of 2023 and we’re still working to see which ferns do best here. All the wood used here has been collected from the gardens at Riverhill. Have a look for:
The Shiny Holly Fern on the rock to the right is a very recent fern which was discovered in America a few years ago – so recent, it hasn’t been given a scientific name yet.
Underneath the Oak stump at the far left is Adiantum venustum (Himalayan Maidenhair). It’s doing well so far, but is very vulnerable to being nibbled by mice. We’re using lemon oil to try and deter them. You will find lots more Maidenhair in the area around the Dell.
The Polypodium interjectum planted in the log on the left (we call that log ‘The River’) is an example of ‘epiphytic’ growth, where a plant is growing on another plant. There’s some more of this at the end of the path by the Wisteria.
There’s some more Polypodium interjectum growing on the Oak stump, but this one got here on its own. We can only assume it’s from spores that came from that other Polypodium by the Wisteria, but if it did, those spores got here against the prevailing wind.
Below the Oak stump is Polypodium x mantoniae which is a hybrid created in the last century by crossing Polypodium interjectum and Polypodium vulgare. There are examples of both in front of you – notice how different the child is from its parents.
IMAGES: left - The Stumpery , Right - Polypodium interjectum growing on the log, with Adiantum pedatum in front of it and Dryopteris erythrosora behind
By the Pond
When it was first built, it had been hoped to find a natural source of water to feed the pond; this was not possible – all the natural springs emerge lower down the hill. These days the water is pumped round from the pond to feed the cascade.
On your right at the entrance to this area the clump of Adiantum venustum (Himalayan maidenhair) is spreading nicely. This lovely fern is a good example of the range of shapes and textures ferns have achieved, not at all like the traditional idea of what a fern should look like.
We have two clumps of Davallia perdurans (Rabbit’s foot fern) growing on the rocks on either side of the area. This is an example of lithophytic growth, where the fern is growing in the moss on the rock. Look carefully and you can see the brown rhizomes covered in tiny hairs spreading across the rock.
The large ferns growing at the edge of the pond are Osmunda regalis (Royal fern). Its spores are produced in fluffy looking tips on the fronds that can look remarkably like flowers, hence its other name of flowering fern.
On the top of the bank above the pond you will see three tree ferns (these are Dicksonia antarctica). Coming from the forests 0f Tasmania, they need special care and ours are still settling in. They need regular watering to keep them moist and are wrapped up in the Winter against the frost. They used to have their own irrigation system until the squirrels ate it!
Look around you carefully, and you’ll see new ferns appearing everywhere on and between the rocks. They’re called sporelings – the fern’s equivalent of a seedling. Invasive thugs are discouraged, otherwise we’re letting them get on with it.
IMAGES: left - Osmunda regalis , Right - Adiantum venustum
The Dell
In this area, we’re concentrating on ferns that have to be seen close up to be appreciated. Do please take your time to enjoy them.
Polystichum setiferum ‘Cristato-pinnulum’ (in the Island Bed). This unusual looking fern is a cultivar dating from the 1890s that was originally thought to be lost. Recently rediscovered, we’re very lucky to have two of them.
The Polystichum setiferum next to it is special as it comes from South Africa.
Athyrium filix-femina ‘Frizelliae’ (also in the Island Bed) is called the Tatting Fern. If you’ve never come across tatting, look it up and you’ll see why it’s got that name.
Athyrium nipponicum (Japanese painted fern) has some lovely delicate colours. New cultivars of this fern are being created all the time.
Towards the Wisteria
We’re continuing the theme of ‘ferns are not all the same’ along this path, with a variety of ferns on both sides. The focus has to be the Wisteria at the far end; do please take a few moments to stop and admire it. We don’t know how old it is, certainly as old as the Rock Garden, probably older. We’re not even sure how many there are, anything between one and three. Look carefully at the way it has wrapped itself round the trees; you can see it everywhere. It doesn’t blossom very often, but when it does, the sight and smell is stunning.
We’re looking for variety in texture here, from the flatness of the Polystichum aculeatum on either side at the start of the path to the crisped texture of the Dryopteris ‘Crispum stableri’ and the Asplenium scolopendrium ‘Angustatum’ and Cyrtomium falcatum at the other end,Don’t be fooled by the Cyrtomium falcatum (also called the Holly fern) at the end of the path on the right. It’s often confused with a Mahonia but it really is a fern.
Have a look at the little clump of Polypodium by the tree on the right - there are three different ones there – and contrast them with the Polystichum setiferum ‘Congestum’ next to them. Two entirely different families that at first sight look very similar, but on closer inspection aren’t.
Don’t be fooled by the Cyrtomium falcatum (also called the Holly fern) at the end of the path on the right. It’s often confused with a Mahonia but it really is a fern.
IMAGES: left - Nature’s sculpture , Right - The Wisteria in blossom