Aphids a Problem for Desert Artichokes

Q. I asked you before about tiny black bugs on my artichoke plant. After consulting you and the PC, I found a solution of Neem Oil extract from Garden Safe and sprayed it, hosed it down a couple times and cut off the top few inches. No pests since then. The main plant is dying and there are several suckers growing from the sides.  I have been looking online for care of the plant.

Aphids are a big problem on artichokes wherever you live but those and whiteflies almost make you pull your hair out. They cause the lower leaves, the older ones to turn yellow and collapse/die. Remove them. The plant doesn't need the lower leaves. They're always in the dark anyway and they are impossible to spray.

A. I never found Neem Oil very effective for insect control. Others have. I am glad you found a name brand that works for you, e.g. Garden Safe. Neem Oil is a “natural” pesticide, sometimes labeled organic, that has had some problems with quality control.

Not the same Neem Oil mentioned by the reader and making sure you select the right Neem Oil is critical. Different processes are used to extract Neem Oil and quality control is a problem.

            The effectiveness of Neem Oil apparently is dependent on how it is extracted or “manufactured”. Some brands of Neem Oil work well while others seemingly do not. It sounds like Garden Safe brand may be a good one for you. Let’s hope it stays that way.

 Fact sheet on Neem Oil from the National Pesticide Information Center

            Artichokes, like sunflowers, are aphid magnets. Those little black bugs were probably aphids, commonly found on the underside of artichoke leaves. Aphids are easy to control when they first appear. If left alone, they are not. Once populations build to epidemic numbers, they are difficult to get under control with “natural” or organic sprays.

            Neem Oil must contact the pest to be effective. It requires frequent, repeat applications when populations are small to keep levels of these pests manageable.

            Aphids don't like hot temperatures. Their populations build fastest in the cooler, darker, more humid areas near the soil. This is also where they are more difficult to see. Removing infested leaves helps reduce aphid populations.

            Artichokes produce okay in our hot desert climate during the cooler months but suffer during the heat of the summer. ‘Chokes here tend to be smaller and a little tougher; not the same quality as those produced in cooler, more humid climates.

            Artichokes love the cooler spring and fall months. They grow back quite nicely in the Fall after suffering during the heat of our very hot summers. Fertilize them just before new growth begins.