Companion planting has been shown to be effective at deterring aphids. Certain companion plants emit volatile organic compounds, covering up the scent of attractive host crops or repelling the aphids. Many companion plants act as a valuable extra source of pollen and nectar, which attracts and supports a more significant number of natural predators and parasitoids of aphids. Similarly, planting strips of wildflowers is effective at increasing natural enemy populations. Sowing strips of wildflowers at the margins of crop fields has increased the abundance of a functionally diverse group of natural enemies and parasitoids. Zhang et al. (2010) found that “archipelagos” of scattered small patches of natural habitat among crop fields had the most significant positive effect on predator abundance. When using strips rather than archipelagos, they found that under an organic cropping system, the optimal amount of area to convert to “non-crop habitat” was just 5%, which increased net returns by 27%; however, in a conventional system using insecticides, adding non-crop habitat led to decreased net returns. Agroforestry systems have proven that tree rows planted with an understory of flowering plants potentiates lower aphid damage and increased predator abundance. In a study of apple trees, trees with a flowering understory had a higher density of predators, higher visitation rates by pollinators, lower aphid numbers, and less aphid damage than trees with mown understories. Crops adjacent to the flowering understories supported more predator conducive environments too.

As with many pests, the best method of prevention is to focus on growing a healthy plant. Nutrient imbalances in plants can lower pest resistance or make the plants more attractive to pests. In soybean, potassium deficiency has been linked to higher soybean aphid populations. Excessively high foliar soluble nitrogen levels have been associated with higher abundances of many pests, including aphids, and higher reproductive and growth rates of those pests. Applying inorganic nitrogen fertilizers causes spikes within soluble nitrogen levels, leading to pest infestations. Organic amendments and soil with high organic matter and microbial activity have been shown to slowly release nitrogen and other nutrients, which prevents plants from taking up excess nitrogen and becoming vulnerable to infestation.

Altieri, M. A. and Nicholls, C. I. (2003). Soil fertility management and insect pests: Harmonizing soil and plant health in agroecosystems. Soil & Tillage Research.

Large commercial farms tend to treat aphid problems with synthetic insecticides. However, the use of these products has led to increased resistance to these chemicals, making them less effective. The non-target effects and environmental damage associated with pesticides are also a concern. Essential oils of plants such as thyme and mint have been shown to be effective insecticides against certain aphid species. However, many organic-labeled insecticides for aphids are ineffective when dealing with a serious infestation, meaning many organic growers are forced to use biological control. Aphids are prey to many different predators, and planting a diversity of flowering plants can provide the nectar, pollen, and microclimates necessary to support a population of predators to keep aphids in check. However, if insecticides are used, predator populations are often affected more than the target pest.

Aguilera et al. (2020) investigated the role of different fertilization regimes on the natural predation of aphids. When comparing an organic manure treatment with inorganic fertilizer, they found that the manure treatment helped increase predatory control of aphids by increasing the number of overwintering and emerging carabid beetles (generalist predators of aphids) in the soil.