Fresh bouquets are a beautiful addition to any space but keeping them looking fresh is a challenge. Fortunately, there are strategies that you can employ to help maintain the perkiness and vibrancy of your cut flowers.

One of the tricks to keeping the air quality clear and your flowers fresh is to minimize their exposure to ethylene, a gaseous hormone that flowers and fruit accrue and emit as they ripen. According to Caren Chang, Ph.D., a professor at the University of Maryland who studies the gas, ethylene can promote fruit ripening. This is why placing green bananas near overripe ones will promote the ripening of the green ones.

Unfortunately, ethylene can also make leaves drop and flower petals die. Flowers that have just been cut for a bouquet will give off a lot of ethylene, which is why cut flowers tend to droop quite quickly. Here are two ways to minimize their exposure to any more ethylene gas so that they stay in good shape for longer.

Place them away from fruit bowls

Not all fruits emit the same amount of ethylene. “Tomatoes, apples, bananas, pears, and many other fruits emit a high level of ethylene because, in most plants, the ethylene hormone is an essential hormone for fruit ripening,” Chang says.

The ethylene, once released in the air, can travel far distances. While it makes its way through the air, it disperses and becomes less potent, so if you keep the flowers a fair distance away from fruit, the ethylene will likely not be a problem.

Place them away from grills or fire pits

Ethylene is also a natural byproduct of combustion, so keeping flowers near gas and petroleum can be harmful.

Chang cites one study conducted on the high-traffic Beltway highway in Washington D.C., that saw that ethylene levels from car exhaust stunted the growth of the surrounding plants. “When the ethylene was chemically removed from the Beltway environment, the plants looked much better,” she reported. This is why it’s recommended to keep cut and uncut plants away from gas sources such as car exhaust, fire pits, barbecue grills, and oil lanterns.