The heady scent of tea tree is one of the iconic smells of the Australian bush. And the essential oils derived from tea trees have been used as medicines, first by Indigenous people, then by colonists.

Today, many of us have a bottle of tea tree oil at home, or use shampoo or creams containing it. Tea tree oil is also a major export earner for Australia.

Now, media reports suggest the European Union (EU) is concerned that tea tree oil may affect people’s fertility and may ban imports.

Let’s see whether we really need to worry about any impact of tea tree oil on our reproductive system.

The many uses of tea tree oil

Leaves of Melaleuca alternifolia trees and other species of Melaleuca produce an essential oil that’s used medicinally and in a variety of toiletries and cosmetics. This oil is a complex mixture of nearly 100 aromatic compounds.

Tea tree oil has been used as an antiseptic since it became commercially available in the 1930s. It has antibacterial, antifungal, anti-parasite and antioxidant properties.

Laboratory experiments suggest it may also help reduce inflammation and enhance healing.

It’s used to treat acne, seborrhoeic dermatitis, and as a mouthwash to treat gingivitis (gum disease). However, the clinical evidence for these uses is not strong.

Tea tree oil is also used in cosmetics and toiletries, such as shower gel and face wash, in various concentrations.

Is tea tree oil safe?

The most common adverse effects of tea tree oil are when it’s used on the skin. In some people, the skin can become sensitive and allergic contact dermatitis can develop. This is particularly when used neat (using the pure oil) rather than after using cosmetics and toiletries, which contain lower concentrations.

Acute toxicity, when there are rapid side-effects coming on within minutes, to tea tree oil via skin application is rare.

Drinking tea tree oil, even diluted or in small concentrations, is not recommended as this can be deadly. There have been reports of cases of depression of the central nervous system (where brain activity slows down) and possible injury to the lungs.

How about the reproductive system?

The EU has been concerned about the potential impact of tea tree oil on the reproductive system for several years.

In November 2023, the European Chemicals Agency’s Committee for Risk Assessment proposed that tea tree oil be classified as a presumed human reproductive toxicant, under category IB.

This classification would mean a ban on tea tree oil in pesticides, and cosmetics and toiletries used in the EU.

The decision rested on the results of reproductive toxicity experiments. This involved administering tea tree oil to rats orally at various concentrations for ten days, before mating. Female rats also received tea tree oil while pregnant and up to the weaning of the offspring.

In the females, measures of fertility, including the number of embryos implanted and mean litter size, were no different to those that had not been given tea tree oil.

At the highest doses, the sperm counts of male rats were lower. But this wasn’t the case for rats given tea tree at 25 milligrams of tea tree oil per kilogram of body-weight per day. That’s around 0.028 millilitres of tea tree oil per kilogram a day.

This doesn’t sound much, but for a 60kg human, that would be equivalent to drinking about one-and-a-half millilitres of pure tea tree oil a day. Nobody is going to be drinking that amount day in, day out. Virtually every application says not to ingest any tea tree oil because of its known human oral toxicity.

This is the level that has no effect on reproduction. The level for reproductive toxicity is twice that.

In cosmetics and toiletries, no-one would be exposed to that much tea tree oil. Less than 4% of tea tree oil components are absorbed via the skin. So even if you did smear that much tea tree oil on yourself, the concentration your body would be exposed to is less than a tenth of the amount that has no effect.

Rats also metabolise tea tree oil components differently to humans. They produce a toxic byproduct that affects sperm. By comparison, humans only produce trace levels of this byproduct.

So what happened recently?

In November 2025, another European committee, the Scientific Committee on Consumer Safety gave its update.

It considered the issues of dose and metabolism outlined above. It also considered human pharmacovigilance data (where therapies are monitored over time to track any potential safety issues). The pharmacovigilance data showed no sign of reproductive toxicity associated with human use of existing products.

It considered tea tree oil’s use in cosmetics and toiletries to be safe up to the maximum concentration of:

The United Kingdom has also weighed in. In August 2025, the Health and Safety Executive didn’t classify tea tree oil as a reproductive toxicant.

What this means for the EU’s classification of tea tree oil in the future is unclear. Shifting it to another category – toxicity category 2, a suspected human reproductive toxicant – would be an option.

In a nutshell

Europe’s initial evaluation of tea tree oil as a presumed human reproductive toxicant in 2023 understandably sounds alarming. But the 2025 update has toned down warnings.

The subsequent re-evaluation of evidence – of tea tree oil’s concentrations and applications, species-specific toxicity, and real-world data tracking safety in humans – means we can be much more confident of its safety.

Tea tree oil, when used as directed, is much safer than the headlines suggest.

The vision of a cottage garden may be one of a countryside scene in a rural retreat like the Cotswolds, with clouds of peonies, roses, lupins, delphiniums and all other manner of classic blooms wafting in the summer sun.

“When we think of cottage gardens we do often think of small spaces which are quite heavily planted but with a loose hand,” says writer and gardener Joff Elphick, whose new book, A Year In A Cottage Garden, co-written by Sue O’Neil, documents just that.

“From the point of design we almost let the plants get on with it themselves, so things like self-seeders are encouraged and we like to think that where they seed, the spot they’ve chosen to come up, is the place that’s probably best for them.”

So, what do you expect from a cottage garden in a small space?

“We don’t necessarily expect a lawn but we expect almost a tapestry of plants and maybe a light hand from a design point of view. I like to think it’s grown over the years on its own.

“People are attracted to that tapestry of plants and the idea that in some ways the garden is fairly low maintenance. We let the plants get on with it – that’s the attraction.”

You don’t need an old property

“With the use of pots and the right plants, you can do it. When you live in urban houses or apartments you are wanting to bring a little bit of the countryside in.”

Keep landscaping simple, he suggests, with maybe a gravel path that isn’t overly engineered. And if you have a boundary, wire it up for climbers, or if you have a border you might add a natural wigwam out of hazel sticks or other twiggy stems.

Check your soil

See if your soil is claggy or dry and light, and dig in some organic matter to enrich it, he advises. Leaf mould also is a great additive and plants are more likely to thrive in a balanced soil.

Leave colours loose

“I like to go for mixes where you haven’t got a beautiful blended colour scheme but you’ve just an absolute mix so it doesn’t look like the designer has been at it.”

Support plants early

Plan ahead and get stakes in early, as if the plants have any height it’s important to stop them flopping and smothering other nearby plants.

He suggests a variety of cottage garden plants suitable for small spaces.

Annuals

“They can play a big part because they self-seed around, things like Papaver somniferum, the opium poppy. It’s quite tall but doesn’t take up much ground space and self-seeds, and once the flowers – which come in ranges of pinks and purples – are over, they have wonderful seedheads on top of them.

“The smaller poppies, such as Papaver rhoeas ‘Mother Of Pearl’ and ‘Amazing Grey’, are only about 18in tall, self-seed and come in a wonderful range of colours.

“Nasturtiums are also great for a cottage garden, French marigolds, primulas and petunias are all good, and forget-me-nots are a lovely choice because once you’ve got them you’ll tend to have them forever.

“Honesty is also wonderful, I wouldn’t do without foxgloves and Cosmos bipinnatus is one that we all like to grow.

“If you want to keep the size down you can also go for the Cosmos sonata series.”

Perennials

Choose varieties carefully for a small space, he advises.

“The Hidcote variety of lavender is not too big and fairly well-behaved, and if you’re looking at (wild) geraniums I wouldn’t go for the classic ‘Rozanne’ because it gets big. I’d go for the lower-growing types like the macrorrhizum varieties, which have lovely scented stems and leaves.”

The other plant that has really caught on in the last couple of years is the Erigeron karvinskianus (Mexican fleabane).

“They have really dainty flowers which flower on and on. They are such good performers,” he enthuses. “If you find by late summer that they are a bit straggly you can cut them back by half and they will come back again.”

Be careful which catmint (nepeta) you choose for a small space, he continues.

“They can get huge if you go for the ‘Six Hills Giant’ and don’t be fooled by ‘Walker’s Low’ which gives you the impression it’s going to be small but it’s not. But there are things like ‘Little Trudy’ which is more compact.”

Elphick also wouldn’t be without Alchemilla mollis (lady’s mantle) in a smaller cottage garden, he says.

“Again it’s perennial and can be cut right back to the ground if it starts looking tatty.”

Include flowering shrubs

Heavily scented candidates include Philadelphus (mock orange). “There’s a small one called ‘Manteau d’Hermine’ which grows to about a metre with double white flowers.”

For those who want to grow something tight against a wall, Cotoneaster horizontalis is brilliant, he says. “It has very unnoticeable tiny white flowers in the spring, and then you have berries as well and they make a very good habitat for birds and insects.”

Feature classic favourites

“I’m always a bit careful about recommending delphiniums as I know many gardeners find that they are eaten by the slugs, but if you can overcome that issue, they are great performers.”

Roses are also classic cottage garden favourites. “There’s a rose called ‘Phyllis Bide’, which is not too big and you can train it against a wall. I’m about to try another called ‘Blush Noisette’, which has a pale pink flower and is remarkably trouble-free in terms of disease.

“One climber which is stunning is the Clematis ‘Princess Diana’ which has these tulip-shaped dark pink flowers and it doesn’t get too big.”

Other classics include the orange-peel clematis (C. tangutica), which can get big but if you manage it well it can fit into a lot of places, he says.

“You can cut it to the ground any point in winter to sprig and it will come back like a perennial.”

A Year In A Cottage Garden by Joff Elphick and Sue O’Neill is published by Genus, priced £19.50. Available now