Over the last couple of weeks, temperatures have really begun to cool off overnight, and with the days becoming shorter, plants and flowers are at risk of harm.  

As the temperatures continue to go down, some gardeners have or are in the process of beginning to prepare their vegetable, plant or flower gardens for fall and winter.  

Leslie Cornell, the owner of Cornell Design and Landscape, says there’s no need to panic, but provides some helpful tips to help extend your vegetable garden growing season this fall and prepare your plants for both fall and winter.  

“Some people may want to cover things overnight, depending on your location especially if you're in a low-lying area, you’re going to notice to be more important when we’re getting these night or early morning frosts,” says Cornell. “Something as simple as a sheet is enough to stop frost.” 

“Frost falls from the sky, it isn’t air temperature typically, and all you need to do is prevent that frost from falling on your plant material and your vegetables that you’re trying to get out of the garden,” adds Cornell. 

She notes that a little frost will not harm your garden, but once temperatures get down below zero overnight consistently, people should think about pulling their vegetables out.  

Cornell explains that September is a tricky month due to the wide range of temperature fluctuations. She says when it comes to new hardy perennials, trees, and shrubs in September, to actually starve them of water.  

“When they are young, they are susceptible to being too lush in the fall and if they have their leaves all out, and nice and green, growing and flowering like crazy, then they are going to take a hit really hard when they get frozen. If you go to –1 it’s the same as going in the freezer at –1. Anything that is soft living tissue is going to freeze and you’re going to have some damage.” 

The reason for depleting plants such as trees or shrubs from water is that they naturally produce glycol, which allows the wood to get drier and harder in preparing itself for winter.  

If you typically water your plants once a week, in September you’re probably going to do it once every two weeks even when there are warmer days.  

Another way to protect woody plants such as trees from sun or wind damage throughout the winter or fall is to wrap the trunks of newly planted or underdeveloped trees.  

“There are two different kinds of wrapping. You can wrap cedar or juniper trees. That shouldn’t be done until we’ve actually taken a freeze or very close to the end of September, you would use a burlap sack for that.  

The other type of wrapping that can be done is a whitewash, water-based paint, or white wrap, which will reflect the sun off the tree. This is to be done on thinner-skinned trees such as young apple and choke cherry trees.  

“When they’re young, the sun side of that tree can warm up and the sap will flow and when it freezes at night it splits because it explodes due to that extra water in it.” 

Lastly, when it comes to your flower beds, Cornell recommends pulling back the mulch to allow that plant, shrub, or tree to breathe and allow that moisture to freeze overnight. When it does freeze then you can pull that mulch back over, allowing that moisture to stay frozen, which will prevent harm to your plants.