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WAGA Weekly

Each week during the 2020 Awards we'll be providing information, updates, ideas and tips.  You'll find them all here, the latest at the top.  Hope you find them useful - and let us know if you have suggestions for content.

WAGA Weekly 23: 14th September

Mature Trees: Why are they so important?

Trees are important for all forms of native wildlife, including birds, mammals and especially insects. They will add another dimension to your growing area - providing leaves and fruits as a rich larder; habitat for nesting; shade and shelter, plus height for safety.

Mature trees in our towns and cities contribute significantly to our health and well-being in a multitude of ways.  For example, a large tree with a trunk diameter of 75cm (30”) can intercept 10 times more air pollution, can store up to 90 times more carbon and contributes up to 100 times more leaf area to the tree canopy than a 15cm (6”) diameter tree.

Oak forests support more life forms than any other native forest.  A mature oak tree will support over 280 different species of insects supplying many birds with an important food source. In autumn, mammals such as squirrels, badgers and deer feed on acorns.

Flower and leaf buds of English oak are the food plants of the caterpillars of purple hairstreak butterflies.  The soft leaves of English oaks break down with ease in autumn and form a rich leaf mould beneath the tree, supporting invertebrates such as the stag beetle, and fungi, like the oakbug milkcap. Holes and crevices in the tree bark are perfect nesting spots for the pied flycatcher or marsh tit.  Bats also roost in old woodpecker holes or under loose bark, as well as feeding on the rich supply of insects in the tree canopy.

The following list provides ideas for trees for small and large gardens.

Ash, Eventual height 40m (130 ft) Flowers provide nectar for insects, the seeds or ‘keys’ are food for birds and small mammals. Over 41 associated insect species.

Quaking Aspen, Eventual height 20m (65ft)  Aspen colonises new ground and is quick to grow. The leaves move in a magical way, immortalized in the poem ‘Lady of Shallot’- ‘willows whiten, aspens quiver, little breezes dusk and shiver’. Over 90 associated insect species.

Beech, Eventual height 36m (120 ft), also suitable for hedge. Richly coloured autumn leaves and beech nuts, or ‘masts’, provide food for many birds such as tits, chaffinches, nuthatches, as well as squirrels and mice throughout the winter. Over 64 associated insect species.

Wild Cherry, Eventual height 9-12m (30-40 ft). Bright red fruit are popular for birds and mammals in early summer. Scented white flowers are attractive to bees and flies in the spring.

Crabapple, Eventual height 9m (30ft)
Pretty pink or white flowers in the spring, followed by small bitter fruit in the autumn. Many mammals such as foxes and badgers, as well as birds, enjoy the fruit. Over 90 associated insect species.

Hazel. Eventual height 6m (20ft ), suitable for hedge.
Classed as a tree or shrub, regular coppicing will keep the tree quite short. Nuts and leaves provide a great deal of food for birds and mammals, including the now rare dormouse.

Holly. Eventual height 20m (65ft), suitable for hedge. The small, pale green scented flowers attract butterflies, bees and other insects, in late spring/early summer. Long-lasting red berries are important winter food for many birds including the thrush and small mammals. Spiny, glossy leaves are eaten by caterpillars of the holly blue butterfly. It is important to have both a female and a male tree for the development of berries.

Hornbeam. Eventual height 24m (80ft) , suitable for hedge.
Dead leaves remain overwinter when grown as a hedge, rather than leaving a bare framework. Seeds are important food source for squirrels and birds.

Rowan. Eventual height 12m (40 ft)
Sweet smelling flowers in the spring attract many insects. Orange berries in the autumn are an important food source for many birds and small mammals such as hedgehogs. Over 28 associated insect species. Can survive in exposed situations.

Silver birch. Eventual height 15m (50 ft)
A beautiful tree, with silvery-white bark. Suitable for small gardens. Older trees play host to bracket fungi and birds such as woodpeckers. Supports 229 associated insect species. Seeds popular with over-wintering birds and small mammals.

White willow. Eventual height 18m (60 ft), suitable for hedge.
Flourishes beside water; useful in reducing soil erosion. Over 200 associated insect species.

WAGA Weekly 22: 7th September

Some perennials left uncut until Spring

What is a Perennial?

A perennial is a plant that lives more than 2 years.  Herbaceous perennials grow and bloom over spring and summer, die back every autumn and winter and then return in the spring from their rootstock.  Many flowers and herbs and some vegetables and fruit are perennials.

To cut back or not?

As Summer comes to an end, you may be tempted to cut back your perennials for winter and to remove all the dead plant matter. The main reason that you would do this is to make your garden beds look tidy.  However, there are some compelling reasons for delaying a clear-up and to leave at least some of your perennials uncut until Spring.


Benefit to Wildlife

The main reason to leave your perennials standing for the Winter is the benefit it has on wildlife.  Overwintering birds rely on the dried up flower seedheads and grasses for food - purple coneflowers are particularly useful for this purpose.  The Winter garden is also a haven for beneficial pollinators.  Several butterfly and bee species use plant debris for overwintering, as do a variety of other insects and invertebrates.

Visual Interest

Another reason to leave your perennial flowers and grasses uncut is the visual interest it provides during the winter.  Ornamental grasses are especially good at spicing up the winter landscape with their varying seedheads, colours and heights.

Reduces winter cold damage

Leaving your perennials uncut for the Winter also provides some insulation to the crown of the plant, helping it survive the cold.


To help wildlife during the Winter, we urge you to accept and to value a more natural garden landscape and to leave at least some of your perennials uncut until Spring.  

WAGA Weekly 21: 31st August

How to introduce a Bog or Permanent wet area to your garden


Most wild gardeners in Cookham now have a pond, but how about a bog garden as well?  The difference between them is that one is a pool of standing water while the other is a patch of slow-draining, waterlogged soil that mimics natural bog conditions. Bogland is exciting because it’s a transitional habitat, linking the wet and dry ecosystems within a landscape. Like any transitional habitat, bogs offer vital resources to a huge variety of wildlife.


Yellow iris, a beautiful native bog plant.


Bringing a touch of boggy splendour to your garden is easier than you might think. Late summer to early autumn is the best time to begin, as your bog will be able to establish itself before winter, and the plants will have the best possible start in spring.

Most of the animals that live in and around the pond should have left for the winter and the soil will still have some warmth but not too much water in it, so will be easier to work. The new bog garden area will then have the winter to settle down and water can collect before the growing season begins in the spring.


A bog garden works equally well adjacent to a pond or on its own. Naturally damp clay soils are ideal, but you can create wet habitat in free-draining soil if you use a liner and introduce topsoil. You can even make a mini-bog in a container – half a barrel lined with plastic is all you need.

Choose which side of the pond you would like to develop for your bog garden. It makes life easier to pick an area where water generally lies during rainy periods.  Mark out the area for the bog garden and lift off the soil to a depth of 20cm. Make sure the edges of the area are level.  Prepare the ground as you would for the pond itself, removing any stones or other debris and, ideally, pre-lining the area with sand and old carpet or newspapers as a protective underlay. Then add your standard butyl liner, making sure it overlaps with the pond liner so that any overflow water from the pond can soak into the bog garden. Puncture the liner a few times with a garden fork, to allow some very slow drainage to take place, as this will mimic natural bog conditions. Refill the area with soil (not topsoil), and some more sand if possible. As with the pond itself, you don’t want too many nutrients in the bog area or it will soon become overgrown nettles and docks. With the liner in place, the area should become waterlogged naturally over the winter, ready for some moisture loving plants to be added in the spring.


The really fun part of a bog garden is choosing the species to plant. Many native species for this habitat have colourful flowers or interesting architectural structure. Species to consider using are:

  • Cuckooflower (Cardamine pratensis)
    A dainty harbinger of the new growing season, with pale pink flowers (March to June) which attract the orange-tip butterfly. Grows up to 60cm tall

  • Marsh Marigold (Caltha palustris)
    Clusters of yellow flowers in April and May, giving strong spring colour with attractive leaves. Grows in manageable clumps of 30- 40cm high.

  • Purple Loosestrife (Lythrum salicaria)
    Another striking plant, up to 1.2m tall with spikes of stunning purple flowers in July and August. A real attraction for many insect species.

  • Great Willowherb (Epilobium hirsutum)
    Produces spikes of pink flowers, in July and August, with long and pointed leaves. The plant can reach a stately 1.5m tall. Grows very quickly so thin out by dividing into clumps in spring or autumn when necessary.

Find out more at

WAGA Weekly 20: 24th August

Bee/Insect Hotel

The average garden is host to 2000 species of insect – most of them are beneficial and worth having around.  In fact, very few of these diverse creatures cause significant damage to our prized plants and many help us to control the ones that do!  Encourage more by building a bee or insect hotel.


A Bee hotel

Solitary bees nest in small hollow stems such as old bamboo canes or holes drilled in blocks of wood, making the cells from their saliva.  It is best to hang a small, stand-alone bee hotel on the wall in a sunny position facing South East to South West and to make sure that it is stable and not rocked by wind.  If there is a risk of tits or Great Spotted Woodpeckers raiding the box (as happened to my bee hotel above this summer) cover the front with chicken wire, which should inhibit the birds from pulling out the canes!

An insect hotel (often called a bug hotel or wildlife hotel) can be as big or small as you have space for.  Make the frame out of an old wooden pallet and stuff it with all sorts of natural materials, providing hidey holes for creatures galore.  The materials can include:

  • corrugated cardboard rolled up and put it in a waterproof cylinder - to create a home for lacewings;

  • dry sticks and pipes – to provide a perfect home for ladybirds;

  • straw -to provide perfect shelter for slugs;

  • bricks, stones and tiles - to provide cool damp conditions for amphibians to over winter;

  • loose bark -a perfect home for beetles, centipedes, spiders and woodlice.

You can build your wildlife hotel at any time of the year, but you may find that you have most natural materials such as straw, dry grass and hollow plants stems in the autumn. Some invertebrates like cool damp conditions whilst others prefer the sun.  So it’s best to try and site your wildlife hotel partly in and partly out of the sun!

Build and site your wildlife hotel well and it could provide shelter for anything from hedgehogs to toads, solitary bees to bumblebees and ladybirds to woodlice. 

Where to buy a bee or insect hotel

If you are short of time or lack DIY skills, you can buy a ready-made bee/wildlife hotel from the RSPB on-line shop at or local garden centres.

WAGA Weekly 19: 17th August

Bird, Bat or Hedgehog box

For an award in our Wild about Gardens scheme, one of our 24 suggestions is to install a bird, bat or hedgehog box, and it is mostly bird boxes people choose.  But we would encourage you to consider providing homes for bats and hedgehogs too.


Bat Box

Bats are increasingly in need of habitats as many of their roosting places have been lost over recent years. These small and captivating creatures often live near to us and use our gardens for food, water and shelter. Putting up a bat box will help conserve them.

Bats do not like draughts, and prefer well insulated boxes where temperature and humidity remain constant. They also need a rough textured wood to cling to. The wood should not be treated because bats are very sensitive to chemicals. A ‘bat ladder’ or other landing area that leads to an entry slit wide enough to admit bats, but narrow enough to keep out predators is also essential, usually 15 – 20 mm. Once up, a bat box cannot be opened legally without a licence. For more information see the website or call the Bat Conservation Trust Helpline: 0345 1300 228.


Hedgehog box

Sadly there are fewer than 1 million hedgehogs left in the UK. They need homes, so making one for them is a great way to encourage them into your garden.

The once common hedgehog is declining in number – since 2002, we have lost around 30% of our hedgehog population. It is becoming increasingly reliant on urban and suburban gardens; indeed, urban populations of hedgehogs have increased by up to a third, while rural populations have halved. This rural decline is likely caused by the loss and degradation of habitats due to pressures such as development, agricultural intensification and climate change.

By providing safe places for hedgehogs to thrive, you’re much more likely to see these prickly creatures in your garden. Adult hedgehogs can travel up to 2km a night looking for food, so it is essential that they can safely pass through urban fences.  Creating a hole 6” or 15 cm square for them is essential.  Next, a simple log pile will encourage the insects they eat and provide basic shelter.  A well ventilated and disguised plastic storage box, sited near a hedge and with a south facing entrance is the next level of shelter,  or you can make a deluxe hedgehog house like this one below.


Bird Box

Why not provide a safe and snug bird house for your garden birds to roost and nest?  The  Royal Society for Proection of Birds’ website – shows bird houses and nest boxes made from sustainable, durable FSC timber, so they're safe for birds and have good insulation properties, making them warm in winter and cool in summer.

The RSPB design bird houses to have the right dimensions and ventilation that birds need, and use non-toxic preservatives. Their nest boxes don't have decorations that predators could cling to and threaten the birds inside.  Do not put boxes in full sun.

If you want to make your own, don’t forget to come along to WildCookham’s Nest Box making annual event on 9 January 2021.  Details nearer the time

WAGA Weekly 18: 3rd August

A herb garden or growing herbs

Growing herbs is a great way of growing produce for yourself – and of benefiting wildlife at the same time! The herb garden can be a very busy wildlife area!


Which herbs are best for wildlife? This is my personal selection:

  • Marjoram - This is an absolute must for your wildlife herb garden! The flowers are irresistible to Gatekeeper butterflies and are one of the best bumblebee magnets.

  • Fennel - This tall hardy perennial in the carrot family grows up to 2m. Broad umbrels of small yellow flowers attract all manner of insects including hoverflies, soldier beetles and solitary wasps.

  • Chives - Eat some and leave some to flower and they will attract bees and other pollinating insects.

  • Thyme - All varieties of this large family of herbs form aromatic low-growing mats of evergreen leaves and thrive in full sun.  Their flowers are a magnet for bees and other pollinating insects. 

  • Sage - Most varieties of this aromatic perennial   produce spikes of flowers which attract bees and other pollinating insects.  Each tubular flower is cleverly designed with a tall hood and a landing pad!

  • Mint - Another aromatic perennial - much hybridised , though  many varieties have a lot of native British water mint somewhere in their ancestry!  Visited by bees and some butterflies like the whites.

  • Angelica - This tall (up to 2.5.m.) biennial culinary herb likes a sunny well-drained position.  It is a magnet for solitary bees, flies, hoverflies and beetles.

Where to grow?

Grow your herbs in a dedicated herb bed or grow them amongst others flowers in the garden or in a pot with good drainage.  Most herbs can cope with few nutrients and dry conditions.  Do not feed.

How to start?

Grow your own plants from seed or buy small plants.

Where to buy?

Most local garden centres sell herbs,or buy from specialist herb growers such as   (500 different varieties of herbs) or

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