A garden for bats and night moths

Why a garden for bats and night moths?

Your garden does not have to go quiet once the sun sets. With the right plants, less artificial light and a bit of open water, you can attract bats and night moths, and that pays off fast: a common pipistrelle bat easily catches a few hundred mosquitoes and other small insects in a single night. Night moths, in turn, pollinate the evening bloomers that stay closed during the day.

The plan itself is simple and cheap: choose flowers that only release their scent after sunset, dim and warm up your outdoor lighting, provide a bit of open water, and consider a bat box. Within a few months you will notice fewer mosquito bites, and within a few years you can watch bats hunting over your lawn at dusk.

Evening bloomers: the foundation of a night garden

Evening bloomers do for bats and night moths what flowering clover does for bees: they signal that food is available. Four species are a safe and proven choice for gardens in Belgium and the Netherlands.

Matthiola longipetala, night-scented stock, is the classic choice. It flowers from July to September with small lilac to white blooms that stay closed by day and open at dusk, releasing a strong scent. Sow in April or May, spaced 20 to 25 centimeters apart, in full sun. Oenothera biennis, evening primrose, is a biennial that opens its yellow flowers within minutes at dusk, from June to September, on plants 60 to 120 centimeters tall. Nicotiana alata, flowering tobacco, is an annual that blooms from July to October with white or pink tubular flowers and smells strongest after dark. Space it 30 centimeters apart in a sheltered border.

Lonicera periclymenum, common honeysuckle, is a native climber that flowers from June to August and smells strongest at dusk. It attracts hawk moths, whose long proboscis can reach deep into the tubular flower. Plant it against a fence or pergola, in sun to partial shade. The berries are not meant to be eaten, but otherwise the plant needs no special precautions in a garden with children or pets.

No harsh light: why darker is better for nocturnal wildlife

Bright, white or bluish light disrupts bats and night moths more than it helps them. Insects fly toward the light and become exhausted or die, while bats that normally hunt in darkness get blinded or simply avoid the lit area altogether.

Replace bright fluorescent or halogen lamps with warm white or amber LED light, ideally under 3000 kelvin. Keep fixtures low, aim them downward and place them close to the house rather than scattered across the garden. A motion sensor with a short runtime of about a minute works better than a lamp that burns all night. Put ambient lighting on a timer that switches off once you go back indoors.

The most sensitive period runs from April to October, when bats are active here, and especially June and July, when females raise their pups in the maternity colony. Keep the edges of your garden, especially hedges, trees and water, as dark as possible during that time: those are the flight routes bats use to travel between their roost and their hunting grounds.

A bat box: when and where to hang one

A bat box is a narrow case with tight slots of 1.5 to 2 centimeters where bats shelter during the day. Buy a box with a rough, untreated wooden interior, or build one yourself from rough-sawn, unplaned boards: bats need to grip the surface with their claws.

Hang the box at least 3 meters high, facing south to southwest, with a clear approach free of branches and as far as possible from bright lighting. Install it in autumn or late winter so it is ready for spring. Be patient: it often takes one to three years before bats discover and start using a new box.

Worth knowing: bats and their roosts are legally protected in Belgium and the Netherlands. You may not disturb or remove an occupied box or a bat roost in a loft without good reason. Two boxes placed five to ten meters apart work better than one, leaving room for more than one colony.

Providing water for bats and night moths

Bats drink while flying: they skim low over the water surface and take a sip on the wing. Provide an open water surface of at least 1 by 1 meter, free of overhanging branches or plants, so there is a clear flight path. A pond, a wide rain barrel or a shallow dish all work, as long as the surface itself stays open.

Night moths drink little themselves but take minerals from damp soil and wet leaves. A border you lightly sprinkle in the evening will attract them. Do not add fish to your water feature: fish eat the mosquito larvae that feed bats and some night moths, and without that food source the water point loses its value for nocturnal wildlife.

Managing mosquitoes without chemicals

Mosquitoes are exactly the problem bats solve: a pipistrelle easily eats several hundred to a few thousand small insects a night, depending on what is available. Chemical insecticides are not the answer and are often restricted for private use anyway, much like glyphosate or vinegar and salt on paving, which private individuals are not allowed to use in Belgium and the Netherlands: mosquito sprays also kill the beneficial insects you are trying to attract.

It is far more effective to remove breeding sites. Empty buckets, uncovered rain barrels and shallow saucers under pots weekly, since standing water is a breeding ground. Put a lid on rain barrels and keep pond water moving with a small pump or fountain. Avoid moisture-retaining mulch in full sun, choosing gravel or sand instead on spots that need to dry out quickly. These few steps often halve mosquito numbers without spraying anything.

Pruning and tidying without disturbing nocturnal wildlife

A garden that comes alive at night is not a perfectly tidy garden. Leave some fallen leaves in quiet corners through autumn: caterpillars and pupae of night moths overwinter there until spring. Prune hedges and shrubs outside the breeding season, roughly from March to mid July, when birds are nesting too.

Mow a strip of lawn once a month instead of weekly, so evening bloomers and wild herbs get the chance to flower before being cut again. That way there is always some food available, even between the bloom periods of the plants you added yourself.

Not sure how all these elements fit together in your own garden? On gardenworld.app you can see it first in a preview of your own garden, before you start digging anywhere.

Step by step

Step 1: Choose and sow evening bloomers

Pick from night-scented stock, evening primrose, flowering tobacco and common honeysuckle. Sow the annual and biennial species in April or May, in full sun to partial shade, 20 to 30 centimeters apart. Plant the honeysuckle against a fence or pergola. Water well until the plants are established and flowering.

Step 2: Set up a water point

Dig a small pond or place a wide, shallow basin with at least 1 by 1 meter of open water surface. Keep the surroundings free of overhanging branches so bats can skim low over it. Do not add fish.

Step 3: Hang a bat box

Hang a box with a rough, untreated interior at least 3 meters high, facing south or southwest, with a clear approach. Install it in autumn. Expect it to take one to three years before it gets used.

Step 4: Adjust your garden lighting

Replace bright white light with warm white or amber LED under 3000 kelvin. Place fixtures low and close to the house, with a motion sensor and a short runtime. Keep hedges, trees and water as dark as possible, especially from April to October.

Step 5: Remove mosquito breeding sites

Empty buckets, saucers and uncovered rain barrels weekly. Add a pump or fountain to keep pond water moving. Choose gravel or sand instead of moisture-retaining mulch on spots that need to dry quickly.

Frequently asked questions

What do bats eat besides mosquitoes?

Bats eat almost any small flying insect they come across: night moths, crane flies, small beetles and mayflies. Which type dominates depends on what is available on a given evening. Once bats are hunting above your garden, you will notice your mosquito problem drop noticeably.

Do bats bite, and is that dangerous?

Bats only bite if you handle them, never simply while flying past. A small number can carry a rabies-related virus, but infection requires direct contact with saliva through a bite wound and is extremely rare. Never touch a bat with bare hands, and call a local bat rescue group if you find an injured one.

How do I attract bats without hanging a box?

Evening bloomers, open water and a dark garden edge are often enough on their own: bats are mainly looking for good hunting ground, not a fixed roost in your garden. A box simply adds an extra chance of a permanent roost, but is not required to see bats hunting.

Do night moths damage plants or clothing?

Most garden night moths feed as caterpillars on leaves, just like day butterflies, and that is normal and rarely a real problem. The clothes moth that lives in wardrobes is a completely different, smaller species that does not occur outdoors in the garden. Garden night moths are therefore entirely harmless to your clothing.

See it in your own garden first

Want to know exactly where the evening bloomers, the water point and the bat box fit best before you start digging? Upload a photo of your garden to gardenworld.app and view a free preview of a new design with these plants. The sharp image with a full plant list costs 7.99 euros, one time only, no subscription.