Louisiana in August may not be the most enjoyable time to work in the yard, but rose bushes need attention to ensure good performance this fall, according to LSU AgCenter horticulturist Dr. Allen Owings.
Rose gardens need pruning, disease management and proper fertilization in August for flowering in September and October. The LSU AgCenter horticulturist says late summer pruning of modern rose varieties such as hybrid tea, floribunda, grandiflora and shrub roses should be completed by late August in north Louisiana and early September in south Louisiana.
Owings notes that the pruning should be less severe than that done in February, but it is needed to lessen disease pressure, remove old growth and improve the overall health of the plant.
"It is very important to conduct this pruning or ‘dead-heading’ of flowers and cutting back of foliage if it was not done on a regular basis this growing season," the specialist says.
Pruning accomplishes several things: height is reduced, and new growth, which results in fall flowers, is promoted. In addition, thinning out old, damaged and diseased canes will develop a desirable growth habit.
Cut back large-growing modern rose varieties to a height of 24 inches. Use sharp pruning shears, and make cuts just above outward-facing, visible, dormant buds. Cutting just above this bud will reduce the incidence of cane dieback.
The LSU AgCenter and the LSU College of Agriculture