Cinquefoil, known botanically as potentilla, is a large genus of flowering annual and perennial herbs that are grown as ornamental garden plants. Cinquefoil grows by underground rhizomes and soil surface runners somewhat similarly to the growth habit of strawberries. In addition to its garden role, cinquefoil is also grown for herbal medicine treatments ranging from use as an antiseptic to treatment for intestinal upset. Cinquefoil varietals are relatively low growing and typically used in beds, borders, low hedging, edging and as ground covers.
Water your cinquefoil deeply several times in the fall before the first hard frost comes. This will fortify the plants, tap root and surrounding soil against the drying conditions that can come with winter. Do not soak the soil during periods of frost to avoid damage to the plants, and try to water on sunny days before noon to allow the irrigation to percolate down into the wider soil area.
Cut back your cinquefoil in the late fall after the first frost and the foliage and branching is beginning to die back. In cooler climates where the branches die back to the ground, shear off all of the branches to just an inch or two above the crown. In warmer climates cut back any damaged or dying branches down to the crown, and leave the healthy ones in place.
Mulch over the crown of the plant with at least 3 inches of an organic material such as compost, leaf mold, cocoa bean hulls, shredded bark or well-aged manure. Mulch will protect the plant roots from the cold, keep weeds away and preserve moisture in the soil. Replace the blanket of mulch each successive year in the fall after watering and pruning.