Queen stock is a tender perennial flowering plant that blooms in the spring. Stock has a rich spicy scent and grows tapered flower heads atop tall strong stems. A member of the mustard family, queen stock is a varietal of the matthiola incana species of stock that produces double-petaled blooms. It is hardy in USDA zones 7 to 9 and thrives in a full sun exposure in consistently moist soil. Queen stock prefers frost-free cooler temperatures and will not survive sustained summer heat. In cold and very warm climates queen stock is grown as a seasonal annual.
Water your queen stock regularly through the fall up until the first hard frost. This will reduce stress on the queen stock and help fortify the plants to withstand winter drought conditions. Water to supplement natural rainfall throughout the winter as needed to keep the soil evenly and lightly moist but not constantly wet. Too much water can readily rot the stems of stocks, so moderate moisture in well- drained soil is ideal.
Prune away any damaged or diseased foliage in the fall with clean sharp secateurs. Removing troublesome plant parts in the fall will prevent them from rotting or inviting other disease over the winter. Mulch around the base of the plants with an organic material such as compost, shredded bark, well- aged manure or cocoa bean hulls. Mulching will hold needed moisture to the soil and reduce the need for watering as well as keep down any competitive weeds.
Cut down your queen stock top foliage in the fall after the first hard frost in climates where the plant greens do not overwinter. Use secateurs to shear off the stems down to a few inches above the plant crown at the soil. Lay down at least 3 inches of mulch over the cut crown of the plant, and extend the mulch out at least 6 inches beyond the plant roots for optimal insulation from the cold.