As you look forward to feasting on your artichoke crop, the sight of ants crawling among the thistles of the green globes can be disheartening. Fortunately, you have several options for ant control for artichokes that address the underlying infestation that is attracting the ants. Once you solve the root issue, the ants will move on and leave your artichokes growing healthily into a delicious summer treat.
According to the National Gardening Association (NGA), "Ants crawling on your artichokes are a sign that aphids are present." The ants are attracted to the sugary honeydew substance that the aphids secrete, which is food for the ants. One way to solve the problem is to hose the aphids off the leaves with water. When their food source is no longer present, the ants often go in search of another feeding ground and leave your artichokes alone.
Since ant control for artichokes is largely a matter of controlling aphids, prevention of an aphid infestation is your first line of defense. Colorado State University Denver County Extension Master Gardener recommends placing yellow sticky traps near the artichoke plants. The yellow can lure aphids away from your crops. They add that high nitrogen levels in the plant sap encourages aphids to move in and multiply so they recommend that gardeners avoid high-nitrogen fertilizers around the artichoke stalks. These preventive measures raise your odds of keeping your artichokes aphid and ant-free.
Beneficial insects such as parasitic wasps, lady beetles, syrphid fly and lacewings can also help control aphids and thereby reduce ant infestation in your artichokes. Some nurseries may have insect pathogenic fungi for sale that will attack aphids as well. If the ant infestation persists after you have treated the aphid infestation, try setting ant traps. The NGA recommends a boric acid trap made of 1/2 cup apple jelly and 1-1/4 teaspoons boric acid powder in a jar with several holes punched into the lid and sealed tightly. Lay the jar on its side near the artichoke plant to lure the ants away from your crop.
In addition to hosing the aphids off with water, insecticidal soaps offer a nontoxic way to control aphids. If the plant is heavily infested, your best option may be to prune off the infested parts. If your crop is chronically infested despite your best efforts, you may need to completely root up all the stalks, leaves and fruit and destroy it to avoid spreading to subsequent and nearby crops. Burn all the infested plant material immediately in an area away from the garden.
Many gardeners consider chemical controls a last ditch effort because of environmental and health concerns. Although the ant-attracting aphids are resistant to most chemical insecticides, some chemicals are nontoxic and safe on food crops. Horticultural oil or neem oil can be effective against the aphid infestation and keep the ants from mistaking your artichoke plants as their dinner.