Answer: Extremes in soil pH can attract or eliminate insects but I don't recommend you try to adjust your soil's pH. If you did, you might find that no plants at all would grow. I think your plants and the beneficial insects you want to attract will do best if you amend your soil with organic matter. You can start small - a single flower bed, for instance. Dig out all the plants, then spread 4-5" of organic matter (compost, aged manure, etc.) over the top of the soil. Dig it in to a depth of 8-10", then level the area and plant or replant. Once the planting is finished, spread another 2-3" of organic matter over the bare soil to help suppress weeds and slow evaporation. Systematically going through your landscape and amending the soil will result in wonderfully rich and well draining soil, which will help your plants thrive. Healthy plants are better able to tolerate insect populations. And, if you have lots of different kinds of flowers blooming all season long, you'll attract beneficial insects. These beneficials will help keep the populations of destructive insects in check.
Good luck with your landscape!
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