I'm not sure of you have notice, but your parents are the same species as the rest of the people around them and fit in the same ecological niche. There is, of

I'm not sure of you have notice, but your parents are the same species as the rest of the people around them and fit in the same ecological niche. There is, of course no wholy correct answer about 'how many centuries back you draw the line', but broadly speaking, pragmatically, it is worth planting plants that help support the rich web of ecological connections that the locality supports. The longer established the plant in the ecology, the more likely it is that some species' caterpillar will live in it, or that there will be a pollinating insect that spends on its shape of flower, or there will be a bird that will like its fibres to build a nest etc. These are things worth nurturing.