These luscious plants help to keep you cool. What are they?

There’s a lot of razzmatazz out in the garden during the gloriously long days of summer. But when temperatures soar, keeping cool suddenly feels more desirable. Plants are amazing beasts that have the ability to cool the air around them. This applies both indoors and out. Do you recognise the family of plants from which the unfurling greenery is emerging?

Ferns are a case in point. Most of them thrive in shady areas and some even cope with dry shade conditions under trees. They look at home on riverbanks and alongside woodland edges where they provide a perfect biodiversity feature and habitat for minibeasts. They also look pretty cool when planted en-masse in gardens where their lush foliage add both softness and movement.

Even thinking about them makes you feel cool.

Cover the soil

All groundcover plants shade the soil from the strong heat of the sun, thereby minimising evaporation of moisture and creating a damp micro-climate. They move the air around through transpiration, thus creating a slight drop in temperature above the plants. The groundcover plant Pachysandra terminalis (pictured above) helps to keep things cool underneath.

Even a sunny border can have shady areas under shrubs and each little niche creates a planting opportunity. Cover the soil with plants and you’ll reduce your workload. Fewer spaces for weeds, better water conservation, great places for birds to forage for breakfast and a wonderful visual feast too. Periwinkle (above) is an evergreen groundcover that is very useful in dark, shady places

Heuchera (above) are great groundcovering plants too. There are evergreen and deciduous varieties.

If you decide that fabulous ferns or other groundcover plants are for you, consider the following factors before choosing a species:

1. Are you planting in a damp situation? Wet, even?

2. Is it shady or sunny?

3. If the area is under other plants or near tree roots, is it dry shade?

4. Do you want evergreen or deciduous ferns?

5. How tall would you like your ferns to grow?

6. Do you want them to provide architectural interest or an understated carpet-covering?

Here’s some recommendations for foliage groundcover plants:

1: Delightful damp-lovers:

Dryopteris including D. erythrosora (above). This beauty is deciduous and it has coppery-red coloured young foliage, maturing to dark green. It grows to a height of around 60cms. Dryopteris is often called the wood fern, the male or buckler fern and it includes about 250 species of different types. 

Dryopteris affinis ‘Cristata The King’ is a stately cultivar of the native fern Dryopteris affinis and it’s semi-evergreen, in that it retains most of its leaves in the winter, but not all. Young fronds are golden lime and as they mature the colour changes to fresh, mid green, it reaches a height of around 90cms.

Blechnum spicant, the hard or deer fern, is a hugely successful, native fern. It's rather beautiful, with feathery green fronds which tend to form a mounded, rosette-like shape to a height of up to 50cms. It’s a hardy, tough evergreen which is native to the UK.

Osmunda regalis is another UK native and this can cope with just about any amount of moisture. It is happy even in full sun (provided the soil doesn’t dry out). It has an upright shade and produces good autumn russet colour before losing its fronds in winter.

2: Choose the right light-level:

If you have a sunny spot, you’ll need to provide ample water for ferns. There are three Osmunda species, all of which can cope with full sunshine for at least part of the day.

Athyrium filix-femina, (pictured above), also known as the lady fern, is a beautiful species for sunny spots. Of course, it needs moisture at its roots but this deciduous fern can cope with exposed sites in even full sun. Expect it to grow to a height of up to 80cms in a cheery clump of fresh-green fronds.

Then there’s the ‘semi-desert’ ferns such as Cheilanthes lanosa, (pictured below) which can easily cope with full sun and dry soil. The ‘hairy lip fern’ is known as such because the stalk and midrib of the fronds are covered in long hairs, hence their tolerance to drought. They’re not fully hardy here in the UK, however and will need winter protection.

3: Plants for dry shade:

Every hardy UK fern would prefer some sort of moisture, but some can cope with dry shade once they are fully established. These include Polystichum setiferum which will grow to about 70cm tall and Dryopteris cristata ‘The King’. Polypodium vulgare (pictured below) is another dry-tolerant option, in fact this evergreen native is one of the most versatile of all. It forms a diminutive, 30cm high mound of dark, evergreen fronds with a slight sheen.

Not forgetting groundcover perennials such as Epimedium and ornamental grasses including the pheasant tailed grass, Anemanthele lessoniana, the carpet forming Ophiopogon planiscapus and Carex  such as C. ‘Ice Dance’ and C. ‘Evergold’, all of which can thrive in dry shade. Carex forms a near, small mound, as you can see in the picture below.

4: Evergreen ferns

These provide year-round interest and there are many delightful varieties. They include Cyrtomium fortunei, a range of different Polystichum (pictured below), many different Dryopteris, Blechnum spicant, and the stately Woodwardia fimbriata, to name but a few.

5: Tall and architectural:

There’s probably no better known or loved tall fern that Dicksonia antarctica, the tree fern. They can grow to three or more metres high, with a similar spread, but very, very slowly! Few plants beat the architectural merits of this ancient giant which has a tree-like stem, topped with spreading fronds.

The common ostrich fern, Matteucia struthiopteris is also well-loved for its structural, shuttlecock or vase-shape. These fresh green, deciduous ferns can grow to 1.5m tall during summer . Even larger is the Royal Fern, Osmunda regalis, which reaches heights of up to 2m. It is, indeed, regal, with  feathery fronds and a tall, rounded personality.

6: A green carpet:

Low, mounding plants that look effective when planted in large numbers include the oak fern, Gymnocarpium dryopteris  (pictured below) which provides a goldish-green, uplifting cover in shady areas, lightening up dark places with ease. Then there’s that beautiful Blechnum which is oh-so-versatile; various Polystichum, Athyrium and Adiantum, to name but a few. And don’t forget grasses such as the wonderful Japanese forest grass, Hakonechloa,  in all its various, indisputably wonderful forms.

Aren’t we spoilt for choice? Choose ferns and groundcover plants to keep you cool!