When we take this approach, we must also analyze the value of plants on more than one level. Yes, natives are important for the survival of native insects which in turn feed bird population, etc.. but some have more general value or for specific values for individual gardens. I have a scale I use ranking plants with agressive nonnatives at one end and natives with added value at the other. Plants that are exotic invasives harm ecosystems, displacing native diversity with monoculture, ex. Privet; exotic plants that are not aggressive but will spread outside the area they are planted and also provide no benefits, for ex. Mahonia; Aggressive Natives that have little value, for ex. Dog Fennel; Nonspreading Exotics that can be beneficial, for ex.Sarcoccoa and Beneficial Natives, ex. Doghobble. How do we make these determinations? Sometimes it is personal experience. Sometimes it is based on research.When we value beneficial plants, we can start by looking at keystone species that are integral to micro ecosystems, ex. Oaks. Then we look at combinations of plants that work together in those micro ecosystems. We can also look at plants that are pollinator and bird attractors, ex. Swamp Milkweed or Black Haw.
Then we look at the diversity of habitats that could be found in your area. What are existing around your property? What is the water flow situation? What is the soil type? Considering these factors, then we look at how you utilize your yard? Do you need lawn space for play, garden space? Does it need to be a traditional lawn and if so can it be a relatively small one? If not can you use native grasses or a no mow lawns? So we can treat that 25% + area to satisfy your primary needs. Leaves can be blown off small lawns or mulched in. Densely planted beds can be mulched to improve soil viability and ease weeding. Obviously leaf litter is very important to many species, but there are also numerous studies extolling the benefits of mulch. They both provide a blanket for the soil that contains moisture, reduces heat and cold extremes and allows for the slow release of nitrogen into the soil. Creating healthy soil is the bottom of the healthy system pyramid.
