Don’t space plants 12-24″ apart in a sea of wood mulch, especially if you re-apply that wood mulch year after year. Mulch keeps plants in a perpetual state of establishment, denying them the ability to self-sow, spread, mingle, and fill in the gaps that weeds WILL move into (weeds love thick wood mulch). Plant tightly.
Use plants that build up the layers. Force plants to struggle and jockey for position. Some will fade away, and that’s ok. The competition encourages resilience and dynamism that shifts the plant palette year to year so different wildlife can partake of new benefits, all while ensuring no one plant can take over.
Plant thickly. Mulch lightly at planting time or not at all. Over plant. Mimic wild conditions where plants are literally on top of one another. And plan for succession from season to season and year to year (which plants will establish first then give way to slower-to-establish plants, bloom time, senescence, winter seed heads, etc).
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