The present invention relates to plant fertilizer compositions and methods that may be used over the growth and blooming or fruiting stage of plant life. In some aspects, the present invention relates to blending plant fertilizer constituents and more particularly, the present invention relates to tailoring the ratio of nutrients in a fertilizer composition by colorizing fertilizer constituents according to their nutrient content and mixing the colorized fertilizers until the resultant color matches a reference color associated with a desired fertilizer composition. In other aspects, the present invention relates to plant fertilizers that avoid the unavailability of calcium due to precipitation, and in additional aspects, dual-component plant fertilizers and related kits and methods are provided that permit admixing of only two fertilizer concentrates while avoiding deleterious precipitation of reactive moieties.