Gardeners Are Using Sugar Water to Help Their Plants Grow but Experts Warn About a Hidden Risk

There’s a mystery that plants and their baby grains hide within themselves, which is not revealed until they’re shoved atop a stove lit up in blue-orange flame. It is only then that the plant grains reveal a mysterious substance locked inside them: sugar. As starch gets liberated from the grains, it spills into the water and turns it foamy, whitish. While still anchored deep inside the soil, this plant used to trap a lot of light energy from the Sun each day in its stems, roots, and leaves. Over time, its digestive system converted all this light energy into the chemical energy of sugar. But is watering plants with sugar water a good idea? Turns out, it’s not. 

Writing on Martha Stewart, an experts explain how sugar water can end up making your plants sadder and madder. It is probably the coolest and most striking feature of a plant that it can make its own food inside its own body. Photosynthesis, we call it. "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,” Amy Jo Detweiler, professor and extension horticulturist at Oregon State University, told the media channel. These plants, she said, have their own “sugar or food factories” built into their bodies.

Inside the cells of most green plants, tiny structures called “chloroplasts” use the sun, air, and water to make their own food. They catch the blue and red light from the Sun to convert it into green light, they metabolize the carbon dioxide in the air to form carbohydrates made of sugar. These carbohydrates are then used to strengthen the roots, make new proteins, build cell walls, or store as a fuel, per NHPBS. “Photosynthesis takes place in the leaves of a plant, which take sunlight and change its light energy into chemical energy, which is stored and used later,” Detweiler explained.

A baby seedling transitioning into an adult and mature plant usually requires a lot of sugar for its growth. However, there is nothing that the extra store-bought sugar can do to help this process along. As far as the self-made sugar is concerned, it only makes the plant stronger and better. But the idea that the same nourishment could be derived from the packet of sugar you bought from the supermarket is blatantly nailed on an erroneous assumption. “Sugar water can be a wonderful boost to dying plants, but I would not recommend it for everyday watering,” Rachel Crow, garden editor, told Homes & Gardens.

“Sugar water can conversely cause damage to plants that are otherwise growing healthily by changing the way their roots absorb moisture and nutrients. Sugar water can prevent plants from getting the right nutrients from the soil and kill the plants instead of helping them,” Crow explained. Plants, she explained, don’t have the same kind of digestive system as humans, and so, the store-bought sugar is not something their bodies will be able to process easily. The Spruce explains that plants usually produce a form of sugar called “monosaccharide.” Whereas, the sugar from grocery stores contains “polysaccharides,” which are highly complex sugars difficult to break down. 

However, this doesn’t call for demonizing the sugar water altogether. In some cases, sugar water may be extremely helpful for the plants, for example, to unfold a tight flower bud, or in the case of cut flowers dipped in water. In addition, sugar water is a perfect addition to the plant’s watering mixture if the gardener wants to attract beneficial insects and pollinators like honeydew, adult lacewings, lady beetles, adult weevil parasitoids, big-eyed bugs, minute pirate bugs, or adult hoverflies. And it doesn’t just attract the good bugs, it also keeps the bad bugs away. On Instagram, @microflowers described how spraying sugar water on her plants warded off insects like cucumber beetles and earwigs.