It’s so frustrating when you put so much care and effort into your houseplants, only to see them struggling to survive for some reason. They’re not flowering, the new shoots look way too thin, and instead of nice big leaves, you’re getting little ones. You’ve heard sugar water can help plants grow, but is that true?
Sugar water does not work for plants because plants absorb nutrients from the soil rather than sugar. Sugar water is good for the soil because it is a source of carbohydrates for beneficial organisms. They break down nutrients in the soil so they are available to the plants.
The good news is sugar water is more than a wives-tale. If you want to learn if sugar water will give you peppy plants, keep reading.
Do plants need sugar?
Sugar is essential for plants to grow properly, but not every kind of sugar. Sugar comes in many forms and is named according to the number of carbohydrates in the molecular formulas.
Plants can’t take table sugar by themselves because it is sucrose, a disaccharide that’s too complex for a plant to absorb.
Instead, plants use glucose, a monosaccharide that they can naturally produce from the combination of carbon dioxide, water, and energy from the sun.
Once absorbed, then the plant turns the simple sugar into a more complex sugar that it can use as energy to grow healthy cells, strong, fibrous walls, grow healthy leaves, bloom flowers, bring water and nutrients from its roots in the soil to the rest of the plant, and be able to do transpiration and respiration.
Sugar is also stored within the plant and is used during the night and winter when the sun isn’t out or provides as much energy.
Is sugar water helpful to plant growth?
Sugar water is helpful to the soil rather than plant growth. The sugar helps the microorganisms boost the process of breaking down nutrients in the soil. The nutrients are then available for the plant roots to absorb.
If plants use sugar, it makes sense that sugar water would be great for them, right?
According to Back Yard Digs, sugar water is actually useful for the soil, rather than the plant. If you have good soil in your pots, and there’s plenty of carbon in the atmosphere (such as inside the house), then there will be plenty of bacteria and other microorganisms that keep the soil nourishing.
The sugar water will energize these microbes so that they break up their food faster and get nutrients to the plant sooner.
In reality, sugar water can be harmful if the solution has too much sugar. Big Yard Digs points out that too much sugar can suffocate the plant by preventing the water from being absorbed into the roots, like a barrier.
When it comes to plants in soil, sugar water can help them grow a little bit faster, but it’s usually not helpful enough to be a common practice. It can also actually harm the plants if the ratio of sugar to water is too high because that can cause reverse osmosis, which actually makes the plant lose water. – Jeremy Yamaguchi, CEO, Lawn Love
If you’ve been using sugar water for a while and the leaves are wilting or yellowing, you’ve been using too much sugar.
Almost 100% of the gardeners I asked were of the opinion that sugar water is not beneficial and they don’t use it for their plants.
What are the dangers of using sugar on plants?
If you use too much sugar water, the pH levels of the soil will change because sugar is acidic. This will cause problems for the microorganisms and plant growth. The excess sugar can attract pests to the soil and plant, causing further damage.
If there is a lot of sugar in the soil, the plant cannot absorb nutrients, and this will cause poor growth in the plant. It may also lead to dehydration in the plant and further lack of nutrients.
Can you use sugar water for dying plants?
You can use sugar water for dying plants if the issue is the unavailability of nutrients to the plant roots. This can happen if the soil has nutrients, but the beneficial organisms cannot break them down for the plant. Sugar can help boost this process to help the organisms.
Before you try pouring sugar water into your plant as a last-ditch effort to keep it alive, be thorough in figuring out why your poor plant is dying.
If you’re not entirely sure, you can take your plant, or a sample of it, to your local greenhouse to see if the staff can help you identify the problem.
This is the quickest way of finding out what’s wrong.
If the problem is that your plant isn’t getting enough nutrients, they’ll suggest good gardening soils or different nutrient products. If you think your soil is fine, sugar water may help.
Can you use sugar water for plants in shock?
You cannot use sugar water for plants in shock because it will not help. The sugar will trigger the plants to produce carbohydrates which will stress the plant further.
In case you didn’t know, plants can go through something called “transplant shock” during the transfer from one area to another if they suffer too much physical abuse, are planted in a smaller area than they were before, or suddenly end up in a new environment that doesn’t meet their needs. It’s most common in trees and shrubs.
Theoretically, sugar water would help the wilting vegetation because damage to the plant can prevent proper photosynthesis, forcing the plants to rely on their internal sugar reserves, which is where the sugar water would come in.
However, Ashley, the “soil scientist” from Gardening Canada warns gardeners to NEVER use sugar water for plants in shock. She explains that the plants don’t metabolize the sugar as we do. Rather, the sugar can trigger the plant to produce carbohydrates.
The only reason this is ever done is to keep blooms alive longer by tricking the plant into believing it’s perfectly healthy and can afford to keep its flowers. But as a means to save your poor shrub or tree, I’m afraid sugar water doesn’t have that kind of miracle mix.
Should you use sugar water for cut flowers?
We widely used cut flowers for aesthetic purpose at home and offices. But they have a limited shelf life that can be extend a bit by putting them in sugar water.
This happens because the cut flowers absorb sugar from the stems, which provides them a boost of carbohydrates and helps them live a little longer.
That’s the reason florists provide a small sachet of plant food to add to the vase when you purchase cut flowers as that contains sugar. Do remember that this is just a temporary effect, and the cut flowers will eventually wilt and die.
Can you use sugar water to attract pollinators?
Sugar water can attract pollinators such as bees, lacewings, ladybugs, and hover flies. But it might not be a good idea to do this because it can harm the plant foliage by attracting pests as well.
When bees consume the sugar water, the honey gets watered down, and it reduces their need to pollinate flowers. So, it’s better to attract the pollinators by growing native plant species that will benefit them for food and life cycle.
Can sugar water control weeds?
Sugar is a carbon nutrient with lack of nitrogen, so it can restrict weed growth. The microorganisms will get nitrogen from the soil, which depletes the levels required for weeds and hence inhibits their growth.
I’m not a fan of this method of weed control because there are far better and effective methods such as mulching or pulling out the weeds.
How to make sugar water for plants
As we’ve discussed, sugar water isn’t the greatest go-to solution, but if you give your plants sugar water, you need to make sure the ratio is correct.
Both Big Yard Digs and Garden Guides suggest having a 4cup water to ¼ cup sugar ratio. Interestingly, one suggests regular white sugar, while the other prefers brown sugar because they believe it has better results.
For both recipes, you need to
- Boil the water
- Put the sugar in the boiling water
- Stir with a spoon until the sugar is dissolved
- Let the solution cool down to room temp
- Pour into the pot.
Garden Bagan points out that you need to take the size and general hardiness of the plant into account.
Some sugar granules don’t dissolve completely in water, so you don’t need to keep pouring sugar water into the pot. Instead, pour the sugar water the first time, and then in the following days, follow up with regular water.
How do you apply sugar water to plants?
Once you have made the sugar solution, put it into the watering can or spray bottle and pour it into the soil near the plant. Avoid getting the sugar solution on the plant foliage because it will end up attracting ants and other pests.
I would suggest only using a small amount in a single spray as we need little to provide the boost of nutrients to microorganisms. I would think 100-200ml of the solution should be sufficient for an average sized plant.
Do monitor the plant after you have applied the sugar water to check if there is any reaction. If you find any issue, it’s best to stop using the sugar water anymore.
How often should you use sugar water for plants?
I would suggest only using it occasionally to give a little boost to the microorganisms in the soil. Too much of it can have an adverse effect on the soil and plants.
It’s best to use the sugar water if you find your plants are wilting or turning yellow because of a lack of nutrients.
But if you notice that the condition is turning worse after using the sugar water, it’s best to stop using it.
Which plants benefit from sugar water?
Sugar water has little benefit, but that can apply for any plant you’re growing in the garden. It may be especially useful for flowering, vegetative, or fruiting plants that can do with a little boost of energy during their growing and fruiting stages.
I would not suggest adding the sugar water to succulents, cacti, or orchids because they have adapted to low-nutrient environments and might not tolerate the boost of sugar water.
How do you store sugar water for plants?
You should put the sugar solution in a clean, and airtight container made with glass or plastic. Keep it in a cool and dark place, such as a cupboard or refrigerator.
Sugar is a natural preservative and can last a long time. But the water solution may go stagnant, so it’s best to use the sugar water within a couple of weeks after you’ve made it.
Can you use commercial drinks that contain sugar?
If too much sugar in the solution “dehydrates” the plant, try looking for drinks that are low on sugar, or carefully watch your leafy friend and dilute as necessary.
Don’t worry too much about the food dyes if you intend to use sugary drinks to water your houseplants.
According to the news site SFGates, the plants will absorb the color without apparent harmful side effects. It can affect the color of the blooms, though.
The cheaper way to give your plants sugar water would be to create the sugar water solution yourself. You have to be willing to take the time to experiment. Always start with lower quantities of sugar.
Can sugar water increase fungal or pest attacks?
Sugar water can cause pest attacks because it may attract some pests to the plant and soil. A common problem is ants that will not harm the plant but farm aphids on the plant leaves. Sugar can also attract pests like flies and gnats to plants. Sugar water won’t increase fungal attacks as those are caused due to moist conditions.
Have you ever left honey or wine out to catch gnats? Or ever accidentally left food out too long only to find black ants marching to and from it?
Sugar will always attract vermin like flies and gnats. Garden Bagan suggests never letting the substance hit the plant itself because it will likely attract pests.
If you add the sugar water directly to the soil and avoid the foliage you should not have trouble with fungal issues. Sugar water can definitely attract ants and should be discontinued immediately. – Tru West, Certified Master Gardener, A Familiar Spirit
What is an alternative to sugar water for plants?
I would recommend using an organic liquid fertilizer, as that is much more effective than sugar water for providing nutrients.
You can use the liquid fertilizer on the soil or as a foliar spray on the foliage of the plants. If you want to encourage leaf growth, use a nitrogen-rich liquid fertilizer such as seaweed or fish emulsion.
If you’re looking to encourage flower and fruit growth, use something that contains good phosphorus and potassium.
What about using molasses?
Molasses is another ingredient used with plants. This is the preferred ingredient of Garden Bagan because it’s the raw product from cane sugar and still has its potassium and phosphorus, which is good for plants.