Only a third of the top gardens at the Chelsea Flower Show over the last 10 years have been designed by women, the Royal Horticultural Society said as it called for more female designers to apply to the event.
The RHS is concerned that a "disproportionately small" number of female garden designers apply to create Chelsea show gardens, which occupy the most high-profile plots, on the Main Avenue of the world renowned flower show.
It is calling for more female designers to apply for them at Chelsea in 2016, as only a third of the almost 200 show gardens created on the Main Avenue in the past decade were designed by women.
Designers for the show are selected on the quality of their design, and female designers including Bunny Guinness, Sarah Eberle, Jinny Blom, Charlotte Rowe and Sarah Price have created award-winning gardens for Chelsea in the past.
This year just two of the 15 show gardens are designed by women, one of whom, Kamelia Bin Zaal, is making her Chelsea debut with "the beauty of Islam", which explores and celebrates Islamic culture.
Multi RHS gold medal winning designer Jo Thompson is returning to Chelsea with an all-female workforce to create the M&G garden "urban retreat", which represents a quintessentially British restorative retreat from the hustle and bustle of the city.
RHS director general Sue Biggs said: "There are a huge number of extremely talented female garden designers out there, but for some reason a disproportionately small number apply to design show gardens at our world famous flower show.
"We really want to change this trend and better reflect the garden design industry, so I urge women designers out there to come forward with your designs."
She suggested the low application rate might be down to a lack of confidence among women.
She said people underestimated the talent and hard work involved in designing a garden at Chelsea, and the scariness of putting one's creative work in front of millions of people who visited the show or watched it on TV.
But she said: "It's not like women are afraid of hard work, I think it's an issue of confidence."
The RHS was not pursuing positive discrimination to get more female designers into the show, she said, but said the society wanted to give women support and encouragement to take part.
Ms Thompson said: "The RHS and Chelsea have made a massive difference to my career and opened so many doors.
"It's a huge commitment, taking up a third of your year to plan and implement, but it's one of the rare processes where you can see your work through from start to finish.
"I've never been treated differently as a female designer, it's a hugely inclusive experience on Main Avenue, and I would advise any women considering it to push themselves forwards and they will see the benefits."