Answer: Clay soil needs organic matter to help loosen it and promote good drainage. There's no way to add organic matter without digging up the plants, amending the soil, then replanting. The easiest way to accomplish this is to dig the plants and place the roots in a tub of water, spread 3"-4" of aged-compost, aged-manure, leaf mold or peat moss over the top of the bed, and dig it in to a depth of 6"-8". Then replant with your perennials. Organic matter will break down over time and will need to be replaced. I cover bare soil with an inch or two of organic mulch material and dig it into the soil at the end of the season to help replenish the bed. There's no need to dig up the perennials again once the initial amendments have been incorporated into the soil, simply dig the mulch material in around the perennial plants each year.
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