After spending time carefully cultivating your sunflower there is nothing more annoying than coming out one morning to see it covered in black bugs.
We all know ants are quite persistent insects too, so sometimes getting rid of them isn’t as easy as you may think.
In this article we are going to look at the age-old question ‘will ants kill my sunflowers?’ and find out why they are attracted to them, how to get rid of them, and just what else those black bugs on your sunflower leaves might be.
Most ants will not kill your sunflowers. In fact, the most common large black ants are actually beneficial to most plants. If you see ants on your sunflowers, it is likely they are farming aphids on them. Getting rid of the aphids should get rid of the ants.
Why Are Ants Attracted to Sunflowers?
There is one word here, and it will form a big part of this entire article…
If you are asking yourself ‘what are ants doing on my sunflowers?’, it is because aphids are there.
In fact, it is quite probable the ants have put the aphids there themselves.
As unlikely as it sounds ants farm the aphids and literally place them on the sunflowers (and many other plants for that matter).
Why would they do this?
When they are feeding aphids excrete a sticky, sweet substance called honeydew, which ants love.
So ants ferry the aphids onto sunflowers. Here the small, soft-bodied aphids eat the sap from young leaves and flower buds and produce the honeydew.
The ants harvest this substance as it is nutrient-rich, and by having the aphids on the sunflower it means a lot less effort for the ant of finding new food sources.
In return, the ants protect the aphids from other pests and parasites that would otherwise eat them.
Aphids are normally found on the underside of leaves and petals
With a few exceptions, which I have outlined below, if you are seeing ants on or around your sunflowers it is because there are aphid colonies there.
Will Ants Damage Sunflowers?
Most Ants Won’t Directly Damage Sunflowers
Generally, ants won’t directly damage sunflowers, the unwanted bugs in this instance are the aphids, not the ants.
But indirectly the ants are doing some damage. Small aphid infestations can quickly get out of hand, and large numbers of aphids will pull water from a sunflower as they feed on it, which could cause stress and damage to the plant.
But on the whole, if you are seeing ants on your sunflower and there are no aphids, then there is no need to worry.
In fact, it could be a good thing.
Large black ants are beneficial to plants. They remove unwanted insects that might attack the sunflower such as caterpillars and also eat away the bad or dead parts of a plant.
Some species create tunnel systems that can help aerate the soil and make it easier for plant roots to receive oxygen and thrive.
Other species encourage plant growth by collecting plant seeds so they can eat a piece of them called Elaisome, with the seeds germinating.
Most ants (but not all), are pretty benign and will not eat plants
But It Does Depend on the Species
There are a few species of ant you want to keep your eye out for:
Leaf Cutter Ants
These ants can strip down plants pretty quickly, as they carry leaves that are up to 50 times their own bodyweight! They don’t actually eat the leaves but instead feed them to a fungus, which they then eat.
Allegheny Mound Ants
These ants build huge mounds and kill any vegetation within 12m to 15m (40ft to 50ft) that might shade their mounds and stop the sun from warming them up.
They do this by injecting formic acid into plants’ stems and bases and have even been known to bring down small trees and shrubs.
Fire ants are the ultimate predators and are notorious for the damage they can cause. They often go to flower beds looking for food and can be a particular pest.
How Can You Keep Ants Off Of Sunflowers?
Use Soapy Water to Get Rid of Aphids
If you want to keep ants off of your sunflowers then you will most likely have to do so by dealing with the pesky aphids.
The quickest and easiest way to do this is to get a spray bottle, fill it with water, add some dish soap and then spray away.
Before you do so check for any other creatures that might be present, that you might not want to harm.
You can also give aphids a quick blast with water from a hose, which should have a similar effect.
Place Cornmeal or Baby Powder at the Base of the Sunflower
Try putting some cornmeal around the base of the sunflower. Ants will eat the cornmeal, which will then expand and kill them.
Baby powder also deters them by covering up the scent of their pheromones which lead them back to their food source each time.
Cover the Stem in Vaseline
Put some vaseline on the stem of a sunflower and the ants either won’t cross it or can’t cross it.
Use Sticky Tape
Place a wide section of sticky tape around the stem of a sunflower, below the first set of leaves.
Again the ants either won’t cross it or will stick to it.
Combine this with bait traps loaded with ant bait at the base of the sunflower, and the ants will have an alternative food source that should get rid of the entire colony.
There are a number of other options you could try:
If your sunflower is in a pot, place a circle of boric acid around it.
Diatomaceous earth is effective against most insects.
Cinnamon and peppermint oil are said to have a similar effect to baby powder and hide pheromone scents.
Try sprinkling cayenne pepper or garlic powder around the base.
If you are seeing ants on your sunflower, it is most likely because they are farming aphids on the plant.
If you can get rid of the aphids, you have nothing to worry about, but a large aphid infestation may damage your plant.
Either way, on their own, most ants are unlikely to damage a sunflower and, in fact, their presence may be beneficial to it.
Grab some soapy water, spray it onto the aphids to get rid of them, and then keep an eye on the situation.
Ants will not harm the sunflower, but the aphids they farm can.
Steve is a one time gardening hater turned into gardening obsessive.
This was all thanks to going to University where a two year stint spent transforming the previously horrific garden of the student house he lived in left him addicted to all things horticultural!
Now with a new house in tow and due to some fortunate circumstances he is free to test out a whole host of gardening equipment.
Find out more about Steve or drop him an email at firstname.lastname@example.org.