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Growing Roses in Northern Climates

Cold hardiness & roses

Definitions: Tip Hardy - hardy throughout; Crown Hardy -Canes will freeze to ground in absence of snow. Tender roses freeze throughout without adequate winter protection.

Overwintering conditions vary from one year to another, primarily due to weather, however cultural practices play a big role in survival rate: feeding, watering, and the health of the plants. Environmental conditions include soil type, precipitation, winter temperature, acclimation and de-acclimation (fall & spring).

Manipulating environment by mulching & adding soil amendments improve survivability. Pruning should be done prior to leafing out (flushing) in spring. Feeding practice depends on the type of rose food used: highly soluble (fast release), low soluble (slow release), organic (slow release). The first application is done right after pruning and the last one about 6-8 weeks before the first frost sets in. Roses require ample moisture in the soil and good drainage. Prior to winter it is important to saturate the soil around the roots, since moisture prevents extreme conditions.

Defining your objectives will help to choose the most suitable roses for your garden. The assigned hardiness zone is based on common knowledge & observations.

Choosing the Site

Light- generally six hours minimum; soil - loamy-sand with high organic matter and slightly acidic (pH 5.5-6.5); Soil amendments include yard compost, bone meal, spaghnum peat moss (to acidify soil), lime (to raise pH). Irrigation and good drainage are important features. Mulch- recycled wood products provide ideal environment for root development.

Spring Planting

Bare Root

Submerge the roots in lukewarm water for one to several days, to allow recovery of water lost during winter storage.

Dig a hole large enough to accommodate the roots and the portion immediately above the bud union. Budded roses require deeper planting than own-root ones, with the "union" set about 4" below soil level.

Mound soil-compost mix (best) over main root area halfway, fill the remainder of the hole with water, then gradually fill in with soil so as to retain the water inside the root zone. A 2-3" mulch layer around the plant shortly afterwards is advisable, to keep weed seeds from germinating and buffering the root zone from the elements.

Potted

Planting potted roses can be done throughout the growing season; however early planting has a better chance for Overwintering.

Dig a hole larger than the container size, set the plant in and repeat the planting procedure as bare-rooted roses.

Important note: planting during summer poses hardship to the plant, as it is to the gardener. Prevent dehydration simply by removing all flowers & flowering buds after planting. Repeat watering judiciously, if no rain, for a few days, but do not overdo!

Spring Pruning

Bushes prune out weak & old canes and shorten healthy ones; use a sharp pruner, and make an angled cut above the 'eye'. Do not prune winter damaged canes until leaves have developed, then cut back to live tissue 3-4 weeks later.

Climbers prune the main cane and side branches a third down.

Winterizing Roses

There are but a few steps to follow to successfully overwinter the roses, starting 6-8 weeks in advance of approaching frost.

  1. Plan ahead your seasonal fertilization program so that there is ample nutrients to coincide with the summer bloom. Your goal should be to gradually minimize the Nitrogen level toward fall.
  2. Quit pruning spent bloom in late summer, to let the flowers go into seed.
  3. Reduce water applications by about 50%, never letting your roses completely dry out.
  4. Mound wood mulch, compost, dirt, straw or dry leaves against the crown.
  5. Climbing Roses: we suggest using Hardy roses for your area.