ST. LOUIS – Thursday was another warm day, but the forecast tells us colder air is on the way. Now is the time to prepare your plants if you want to extend the growing season.

Temperatures are expected to dip into the 30s on Saturday morning, and areas away from metro St. Louis will likely experience their first frost. The Missouri Botanical Garden said that most houseplants are tropical and will need to be brought inside.

Frost advisory

“Once temperatures are below 50 degrees at night consistently, they’re not going to like that. They’re not going to do well,” said Kristina DeYong with the Missouri Botanical Garden.

Since it hasn’t rained recently, DeYong said to water your trees, shrubs, and perennials. Drought-stressed plants are more susceptible to cold damage. 

“We don’t want them to be both thirsty and too cold. So, if anything, it’s best to give those plants a good watering before the cold hits,” she said.

Cool season vegetables, such as cabbage and peas, can handle a brief drop in temperature. DeYong said to protect other plants with a light covering that will trap soil heat around them.

“Any of those summer vegetables, you are going to want to cover those with a row cover, something that goes all the way to the ground. Or even something more natural, like evergreen boughs,” DeYong said.

While the Botanical Garden is preparing for colder temperatures, they are also preparing for a huge fall event. The Best of Missouri Market starts Friday and runs through the weekend. You can shop from more than 100 artisans, crafters, and food producers.

“A lot of them are based in the area, but they do come from all over Missouri. And we do our best as well to find vendors that fit well with the garden’s mission of sustainable products, ethical sourcing,” said Abbie Driver.

The Best of Missouri Market is happening all weekend. Admission is $16 for adults and $5 for kids 12 and younger. There are discounts for Botanical Garden members. The Historic Shaw Art Fair will be happening just down the road on Saturday and Sunday.