Sunflowers (Helianthus spp.) are magnificent plants that add to the glamour of gardens around the country. They’re striking, tough plants that don’t have too many problems. However, they tend to attract ants, sometimes to the plant’s detriment.
Here’s how to keep ants off your sunflowers:
- Clear the aphid population.
- Use sticky barriers on the sunflower stems.
- Plant some natural ant-deterrents.
- Spray natural ant-deterrents around the garden.
- Use organic food-grade diatomaceous earth.
In the rest of this article, I’ll explore each of these solutions in further detail. You don’t need to use all of them at once – however, you may have to use two or more solutions, depending on the severity of the ant infestation on your sunflowers.
1. Clear the Aphid Population
Nectar-drinking ants feeding on the extrafloral nectaries on your sunflowers won’t cause harm to the plant population in your garden. In fact, they’ll likely help pollinate and improve the health of the sunflowers and other plant varieties in the garden. However, if you find too many ants feeding on sticky substances that look like excrement around the stems and leaves, you’re probably dealing with an aphid problem.
Aphid colonies attach themselves to the stalks of sunflowers and on the back of the leaves. Using their sharp, tubular mouths, they dig into the plant, draining the nutritious sap they’re made of. Small aphid populations are harmless, but they’ll damage the sunflower plants in large numbers while also attracting thousands of ants.
The ants feed on the end product of metabolized nitrogen that aphids produce from feeding on the plants. This waste product is sticky, sweet honeydew loved by ants. Ants throng to the sunflowers to feed on this honeydew, lining the way with pheromones for others to follow.
Clearing the aphid population is the best way to reduce the ant population on and around your sunflowers. The first step to achieving this is to rinse the infested plants with a sharp spray of water. Spray thoroughly, making sure to hit the entire stalk and all the leaves in each plant.
Dislodged aphids will die off as they never make it back onto the sunflower stalk. Repeat the process a week later to be sure.
With the aphids gone, you should see a drastic reduction in the number of ants on your sunflower. The water stream also dilutes the spray of pheromones they use to move around your garden, further reducing your ant infestation. For the ants that remain, you can explore the other options we’ll cover here.
2. Use Sticky Barriers on Sunflower Stems
Sticky barriers keep out ants by making it hard for them to get onto the sunflower trunks. The few that try to climb will get stuck, and others will avoid the plant. Catchmaster Barrier Adhesive Kit and Tanglefoot Tree Insect Barrier Tub, both from Amazon.com, are good options here. They’re both easy to apply, and they’re made with environmentally friendly materials.
However, sunflowers tend to react poorly to sticky barriers applied directly to the stalk, and the younger plants may wither. Therefore, it’s best to apply the sticky barrier onto another surface, such as on a masking tape wrapped around the stalk.
Be sure to place the tape high enough off the ground (at least two ft (0.61 m) to reduce the chance of debris catching onto the mix and make sure to keep an eye on the mix. Reapply a fresh layer when it starts to lose efficacy.
3. Plant Some Natural Ant-Deterrents
There are quite a few natural ant-deterrents you can plant in your garden. The good thing about introducing these plants to your garden is that most are useful in other ways. You can cook with them or use them in diffusers to scent your home. Some of the top options include:
4. Spray Natural Ant-deterrents Around the Garden
You can spray natural ant-deterrents around your garden to further speed up the reduction of the population. Some of the options available to you include the following:
- Black or Cayenne Pepper. You can mix this in the soil around the sunflowers or create a pepper solution you can spray around the garden.
- Vinegar. Mix equal parts of vinegar and water to disorient the ants and counter their pheromone trail.
- Lemon Juice. Diluted lemon juice sprayed around your sunflowers will have the same impact as vinegar on the ants.
- Cinnamon. Sprinkling cinnamon around the garden is another effective solution, but it’s typically costlier than other alternatives we’ve covered here.
Before spraying any portion of your garden with any of these natural ant-deterrents, it’s best to test out a small portion – especially if you have other plants in the garden next to your sunflower. Vinegar and pepper spray, for example, can discolor the leaves of more delicate plants.
5. Use Organic Food Grade Diatomaceous Earth
Diatomaceous earth (DE) is a natural product containing the remains of marine phytoplankton. It looks and feels like baking or talcum powder, which may put you off using it in your garden. However, it’s very safe and is a reliable option if you’re looking to keep out ants and other pests from your sunflower.
Diatomaceous earth is also safe to eat. If you eat many grain-based foods, you already consume a decent amount of the material per year. It helps manufacturers store these foods better, keeping grain-eating bugs away. So, if you’re also growing food plants or herbs in your garden, you don’t have to worry about how the substance can affect your health.
You can buy diatomaceous earth in various garden supply stores. Alternatively, you can find it online easily as well. I suggest Earthborn Elements Diatomaceous Earth from Amazon.com. The product comes in a five-gallon (22.73-liter) container, which gives you enough DE to spray on ant trails and hills and around the perimeter of your garden.
Ants love sunflowers either for the nectar they produce or the waste product generated by the aphids that feed on the plant’s sap. You have to first figure out why the ants are there to know the best approach to get rid of them.
Remember, ants aren’t always bad for your sunflower. If you’re not dealing with a large-scale infestation and there are no aphid colonies on your plant, it’s best to allow the ants to go about their business.
- Ehow: Sunflowers & Ants
- SF Gate: Sticky Tree Barriers for Ants
- SF Gate: Ants Raising Aphids on Sunflowers