Is Sugar Water Good for Plants? Experts Weigh In

Sugar, as humans know it, is an essential molecule for many living creatures on this planet. But the idea of using sugar, or a solution of sugar and water, to help plants grow is popular enough on social media to entice many to try it. Does it actually work? Ahead, we asked experts to address whether sugar water can be useful for plants and what to expect if you pour the sweet stuff on your soil. 

Does Sugar Water Help Plants Grow?

The short answer is no: sugar water doesn't help plants grow. For a plant to live, it needs sunlight, water, and air. "One of the coolest features of plants is their ability to make their own food, given they have three elements: sunlight, water, which allows minerals to be taken up through the roots, and air,” says Amy Jo Detweiler, professor and extension horticulturist at Oregon State University. This is the process of photosynthesis, in a nutshell.

When to Use Sugar Water on Plants

If there is one instance where sugar water may help, it’s with cut flowers sitting in water. "The packets you get with cut flowers contain sucrose [aka table sugar] and usually citric acid to lower pH," says Laura Irish-Hanson, extension horticulture educator at the Department of Agricultural and Natural Resource Systems, University of Minnesota Extension. “It also contains a biocide to kill mold, which is a big issue with sugar water."

Unlike plants growing in soil that have roots and an entire system of stored food for growth, cut flowers only have their stems and maybe some leaves. In this sense, sugar within the water can temporarily help the plant keep growing, like to unfold a tight flower bud, but it’s usually only enough food to finish blooming before the flower starts to decay.

What to Use Instead of Sugar Water

For plants that are still living and growing, consider using an organic compost or fertilizer that slowly releases both macronutrients and micronutrients for the plant's long-term health. "Organic fertilizers or compost work to 'feed' the beneficial microbes in the soil, improving soil tilth over time and allowing plants to absorb nutrients more readily," says Detweiler. "If using manure-based compost, make sure it has aged manure and does not have herbicide residue."

Irish-Hanson recommends that gardeners get their soil tested before adding additional fertilizer, as most gardeners don’t need to apply extra fertilizer beyond just using a balanced compost. "Some people give the plant too much nitrogen, and it decreases the flower growth," says Irish-Hanson. For example, if you’ve applied fertilizer for your lawn, that can help the grass grow healthy and lush, but for other plants, too much nitrogen fertilizer just helps the plant make leaves and not flowers.