Winter Preparation for Roses (with revision of lime-sulfur use rate) Purpose of Winter-Protection Prevent frost-heave of roots Keep roses dormant Prevent premature leafing out Clean up and prevent insect and disease problems Correct time to apply winter-protection After fall of leaves such as maple leaves After a couple of hard freezes When the ground is starting to freeze Usually end of November or into December in SE Michigan Getting the plant ready Healthy roses are better able to survive winter – so water & fertilize regularly during the growing season Stop all deadheading & pruning by late August Apply last fertilizer in mid-to-late August (after summer heat cools) Water roses if fall is dry – don’t turn off your irrigation system too early! Fall is a good time to test your soil and adjust pH if needed.  Roses thrive with a soil pH of 6.5 - 6.8 Basic steps of winter protection Clean up Deep watering Securing canes Dormant disease & insect control Anti-desiccant for climbers Apply winter mulch, if needed, with rodent control Clean-up (mid-to-late November or later) Remove leaves from rose; shop vac can help Remove all rose debris from the ground around the rose.  Reason:  disease spores & insect eggs can remain in dead rose leaves Don’t compost rose waste at home to prevent spreading disease Deep watering  – just as ground is getting ready to freeze Secure canes (mid-to-late November or later) Tie climber canes to support Tie long canes of bushy roses together to prevent whipping in winter wind Can do some modest pruning (in late Nov) of canes that are a hazard Dormant disease & insect control (mid-to-late November & March) Can be applied together, in a sprayer or watering can Apply when temp is above 40 deg F and allow to dry in daylight Use warm (not hot) water to dilute Ortho Volck Oil Spray  (Dormant insect control) 5-1/3 oz (10-2/3 tablespoons) per gallon water             **AND** Bonide Lime Sulfur  (Dormant disease control) 3-3/4 oz (7-1/2 tablespoons) per gallon water  this rate was modified in 2007 because of changes in the label instructions for Bonide Lime Sulfur             ---OR---              Combination Spray – Bonide Oil & Lime Sulfur Spray  11-1/4 oz (22.5 tablespoons) per gallon water Put some warm water in sprayer, add chemicals then add rest of water             Always wear eye protection, long sleeves & pants, impervious gloves & footwear.  Note:  Lime sulfur spray is corrosive; can cause skin irritation and eye damage.  It is safe once it dries on the plant. Anti-desiccants for climbers (mid-to-late November) Consider protection of burlap screen if climbers are tender Spray  Wilt-Pruf  instead of Dormant Oil/Lime Sulfur on canes exposed to wind Apply when temp is above 40 deg F; allow to dry in daylight Use warm, not hot, water to dilute Add one part Wilt-Pruf concentrate into five parts water (always add Wilt-Pruf to water, not water to Wilt Pruf) or use Ready-to-Use Spray Reapply Wilt Pruf during a Feb or March thaw             NOTE:  Always store gardening chemicals at temperatures of 50 to 85 deg F.   This means that your garage or garden shed is the worst place to store them! Winter-mulching – purpose is to keep ground frozen; prevent frost-heaving     Don't apply until ground is starting to freeze -- often not before December                         Roses that need heavy mulching (12 - 14 inches): ·         Hybrid teas ·         All grafted roses unless bud union is 3 - 4 inches below soil ·         Some floribundas ·         Some climbers ·         David Austin English roses  Roses that need light mulching (4 - 6 inches): ·         All roses facing first winter in ground ·         “Victorian” antiques – Bourbons and hybrid perpetuals ·         Musk roses and polyanthas ·         Most floribundas & climbers ·         Miniature roses (2 - 3 inches of mulch)              Roses that don’t need winter mulch: ·         Established, own-root plants: o        rugosas o        Canadian Explorers and Morden Parklands o        Old European roses – gallicas, albas, damasks, Portlands, moss, centifolia, species o        Meidiland shrub roses o        Griffith Buck shrub roses o        Knock Out shrub roses Material for mulching ·         Snow (but not ice) – good, but isn’t a reliable cover here ·         Soil from another part of your garden ·         Well-rotted wood chips, grass clippings, compost ·         Ground up oak leaves (avoid maple leaves) ·         Pine boughs, for example Christmas tree limbs ·         Pine needles, ground pine bark (bulk source:  Rock Shoppe outside Plymouth  734-455-5560)              Use collars or cages to hold large amounts of mulch in place               Put rodent poison underneath mulch (for rats, mice, voles)               Remove mulch gradually, all during the month of April Container-grown roses   Dig a hole in ground outdoors & heel in (bury) pot for winter Next best – overwinter in unheated shed or garage o        remember to water monthly o        don’t put pot in plastic bag Don’t try to overwinter as houseplants; roses need dormancy                         Standard (tree) roses Really are annuals in Michigan Can attempt to overwinter container in unheated shed or garage Best to tip & bury entire standard (tree) rose outdoors Common Mistakes with Winter Protection of Roses Rose cones are worthless unless you cut off top, punch holes in them and use them with mulch underneath Most people apply winter mulch much too early Roses should be pruned in spring (late April) not in fall or winter!