Old windowsill tip: Place three herbs on your windowsill to keep spiders out.

This old trick is enjoying a comeback right now.

When temperatures rise and windows stay open for longer, the same problem appears in many homes: eight-legged lodgers make for dark corners, window frames and curtain rails. Rather than reaching straight for a can of insecticide, more and more people are turning to a surprisingly simple, time-tested method that works without chemicals - using plants that almost everyone knows from the kitchen.

Why Granny’s windowsill hardly ever had spiders

Before insect sprays were sold in supermarkets, people worked with whatever the garden could provide. Many windowsills were lined with certain terracotta pots, arranged in a strict pattern: strongly scented herbs placed close together. The aim was clear - to create an invisible barrier of smell.

It is precisely classic kitchen herbs such as lavender, mint and basil that release scent compounds which drive away spiders and many other crawling creatures.

While these aromas are pleasant, even calming, to people, they overwhelm the highly sensitive sensory organs of spiders. They consistently avoid these areas and move elsewhere - ideally outdoors.

Three herbs spiders really do not like

Lavender: a cloud of scent against unwelcome visitors

Lavender has long been known for its soothing effect. The plant contains powerful essential oils that give off a strong fragrance. That is exactly what creates the protective effect at windows and doors.

For spiders, these aromatic clouds are a source of stress. Their fine sensors become overstimulated, and orientation and hunting no longer work properly. The logical result: they turn back before they even reach the home.

For lavender to work well on a windowsill, it mainly needs:

• a very free-draining soil mix (potting compost combined with sand or perlite)
• a bright position with plenty of light
• little water - it should only be watered when the top of the soil feels dry

If several pots are placed in a row, the scent barrier becomes noticeably stronger. Especially on south-facing windows, lavender not only looks attractive, but also acts all day and night as a natural doorman.

Mint: fresh smell, strong effect

Mint is energising for many people, but off-putting for spiders. Its leaves are packed with menthol, a substance that continuously releases the smallest scent particles into the air. For spiders, that means the surroundings feel overloaded and unsafe.

A particular advantage is that mint is more forgiving of care mistakes than many other herbs. If a few basic rules are followed, you can quickly have a dense, fragrant pot by the window.

Kept in its own pot, mint remains manageable - and turns the window frame into an invisible boundary that spiders are reluctant to cross.

It is important not to place the plant in the same box as other herbs. Mint forms vigorous underground runners and would otherwise crowd out weaker neighbours. Better options are:

• a single deep pot, around 20 cm deep
• humus-rich soil that stays slightly moist
• a bright spot without constant, direct sunlight

If you like, you can harvest a few leaves now and then for tea or cocktails. The scent remains, the plant branches out more strongly, and it becomes even denser.

Basil: a kitchen favourite with a side job as a sentry

Most people know basil from tomato salad. What is less well known is that its essential oils noticeably irritate many crawling insects. Its slightly peppery, spicy fragrance fits perfectly into the scent mix alongside lavender and mint.

The right location determines whether basil stays vigorous or soon wilts away. The plant likes warmth and light, but it cannot cope with relentless midday sun through glass.

Factor	Recommendation for basil
Light	bright and warm, with no permanent midday heat
Water	water regularly, keeping the soil slightly moist
Care	pinch out the tips regularly and remove flower buds

If you keep pinching out the growing tips, you encourage bushier growth. That produces more leaves - and more fragrance to keep spiders away.

The best time to start the herb pots

The period around the end of March and the early spring is especially suitable. The sun is gaining strength, the days are getting longer, and plants begin to grow in earnest without immediately being scorched by summer heat.

If you fill your windowsill with lavender, mint and basil in spring, you build the scent barrier before peak spider season begins.

Young plants from a garden centre or DIY store can be repotted straight into decorative containers. Important: make sure the pots have drainage holes in the base so water does not sit in the soil. On narrow windowsills, long boxes are useful, with lavender and basil side by side and mint in its own separate pot.

How to create a closed protective line at the window

The right arrangement on the windowsill

For this old windowsill trick to work, plant density matters most. A few lonely pots spaced 60 cm apart will only achieve limited results. The goal is a more or less continuous green boundary right by the frame.

A practical combination is:

• one mint plant on each side of the window
• one or two lavender pots in the middle
• a basil plant in front of, or between, them

This way, the different scents overlap, and the area immediately in front of the opening becomes as unattractive as possible for spiders. At the same time, everything remains visually light and friendly - unlike glue traps or nets.

Advantages over chemical products

Insect sprays are convenient, but they bring several problems with them: irritating vapours in the air, residues on surfaces, and costs if they are used often. Herbs on the windowsill work more quietly, but continuously.

The main everyday benefits are:

• no toxic mist in the home
• a pleasant fragrance instead of a chemical smell
• fresh herbs for tea and cooking
• a visual lift for both the exterior and the interior

Many households also report that not only spiders, but also ants and other small crawlers, appear less often around the windows.

What to know about spiders and fragrances

Spiders can make many people uneasy, but they play an important role in the ecosystem because they eat flies and other insects. This herb trick does not kill them; it simply drives them away. The animals just move on to a quieter place.

The effect is based on the scent compounds, more precisely the essential oils. These substances are highly concentrated in the leaves and flowers. Heat and moving air - for example, a slight draught through a tilted window - increase the effect because more fragrance is carried into the room and outdoors.

If you are particularly sensitive to strong smells, start with smaller quantities and see how the indoor atmosphere changes. Lavender, in particular, can become strongly scented if several pots are placed close to a living room or bedroom window.

It is also worth remembering that some herbs are more suitable for different rooms. Basil, for instance, does best in warmer indoor spots, while mint can cope well where the air is a little cooler. If you have several windows, you can therefore vary the planting instead of using the same arrangement everywhere.

Practical extra tips for a spider-resistant home

The herb pots work best when a few simple habits are added around the house. Spiders love dust, dark corners and undisturbed nooks.

• Wipe window frames inside and out regularly
• remove old webs completely, rather than just pulling them away
• seal gaps and cracks around frames, roller shutter boxes and joints
• do not place light sources directly next to an open window in the evening

If you also rearrange the pots from time to time, remove dry leaves and keep the herbs young by pruning them back, you benefit twice over: fewer spiders and a lively, green window display that visibly improves any home.

For households with pets or small children, it is sensible to place the pots where they cannot be knocked over easily. The herbs themselves are generally harmless in a decorative setting, but concentrated leaves and essential oils should not be treated like snacks. A stable pot, good drainage and a tidy windowsill help the display stay attractive and safe.

Over the course of the year, it can also make sense to refresh the planting. When one herb starts to look tired, it is better to cut it back or replace it than to let the whole arrangement become sparse. A well-kept windowsill not only gives off more scent, but also keeps working as a subtle natural barrier for longer.