Roses That Hold Up in Indiana

Rugosas, Explorer series roses and a short list of tough shrub roses come through Indiana winters with little or no protection. Hybrid teas, grafted tree roses and most potted miniatures do not, and they fill much of the garden center shelf anyway. What you carry to the register matters more than anything you do in January. Below are the roses that hold up, the ones that only look the part, and the label details that separate them. For the basics of care, see growing roses in Indiana.

Which roses survive a Indiana winter

The USDA Plant Hardiness Zone Map rests on a single number, the average annual extreme minimum temperature. Across Indiana it runs from 5b to 7a. The northern counties sit at the cold end, the Ohio River counties at the warm end, and everything between shifts a half zone at a time. Look up the zone for your own address before you shop. A rose rated for zone 5 or lower is safe anywhere in the state.

Which rose types clear zone 5b without help?

Rugosas lead the list. Their wood is hardy far beyond anything Indiana delivers, and they shrug off road salt and sandy soil as well. The Explorer series, bred in Canada for Canadian winters, comes next. Most are grown on their own roots, and the group includes compact shrubs and tall climbers. Modern landscape shrub roses, including the Knock Out family, usually get through zone 5b with at most some dead cane tips. Old once-blooming garden roses such as gallicas and albas are tough too, though they bloom only in early summer.

Where do hybrid teas fall short?

Hybrid teas, floribundas and grandifloras were bred for mild climates, and nearly all are sold grafted onto a rootstock. In the warmer zones, 6b and 7a, they often live through winter with a mulch mound. In the colder zones, 5b and 6a, the canes commonly die back to the soil line or the snow line, and in a hard winter the graft itself dies. That describes the northern part of the state and cold hollows farther south.

Timing of the cold matters too. At the Indianapolis reference station, NOAA’s climate normals put the last spring 32F freeze between April 9 and April 21, and the first fall freeze between October 21 and October 30. Southern Indiana runs a fortnight or more ahead in spring and behind in fall. Purdue warns of roughly a 10% chance of a 32F freeze after the spring window closes. Hardy roses shrug off a nipped shoot. Tender ones lose the growth they just spent weeks making.

Named roses that hold up here

A hardiness claim means little until it has a name attached. These are the cultivars most often available at nurseries and by mail order, and what each one can take.

Which are the safest buys for a first rose?

Hansa and Therese Bugnet are the two I would hand a beginner in the northern half of the state. Hansa is a dense, thorny rugosa with deep magenta, clove-scented flowers and big orange-red hips in fall. Therese Bugnet is an upright hybrid rugosa with softer pink flowers on nearly thornless red canes, and it blooms repeatedly where Hansa mostly pauses between flushes. Both resist the leaf diseases that plague tender roses. Both also sucker, so give them a spot where a few extra shoots will not matter.

Knock Out earned its place by being the easiest rose to find and the least fussy to keep. It tolerates a 5b winter with minor tip loss, and a spring trim to healthy green wood is the only repair most plants need. Its reputation for disease resistance is mostly deserved. It is not immune to everything, though, and the rose diseases Indiana’s climate brings include rose rosette, which can hit this family.

Which climbers hold up?

William Baffin is the dependable choice. It is an Explorer climber that tolerates the coldest Indiana winter, grows tall enough to cover a fence, and sets semi-double pink flowers in early summer with some rebloom afterward. John Cabot, from the same series, is another option. New Dawn is the famous soft-pink climber and an excellent rose, but it is the borderline case in the group. In zone 6 and warmer it behaves. In 5b, a bad winter can kill canes that were due to bloom first, so lay the canes down and cover them if you grow it in the north.

Sold here, but not for this zone

Garden centers buy from national suppliers. The rack in Indiana looks much like the rack in Georgia or Oregon, and a pretty color photo on the tag says nothing about winter. Roses that need work, or will probably fail without it, show up on shelves here every spring.

Which roses on the shelf need winter work?

• Hybrid teas, which are grafted and fail first in zones 5b and 6a
• Grandifloras and most floribundas, with the same graft and the same weakness
• Tree roses, also called standards, where the graft sits at the top of a bare trunk
• Potted miniatures sold as gift plants, often forced indoors and short on root

For all of these, plan to mound soil over the graft union after the ground begins to freeze. Hold off until then, because mounding early traps warmth and invites shoots that the first hard cold will kill. Full instructions are in protecting roses through an Indiana winter.

Are English roses and tree roses worth the risk?

English-style roses are the gray area. Hardiness varies a great deal between cultivars, and the ones sold with a “zones 5 to 9” tag are right at the edge in the north. They often survive, but they lose canes, and the plant that returns is smaller and slower to bloom. Tree roses are the hardest to carry through. The graft is exposed on top of a trunk with no snow cover at all, and wrapping the whole plant or tipping it into a trench is a fall chore. If the work sounds like too much, a standard-form rugosa or shrub rose gives a similar look with far less trouble.

What to check on the label before buying

Three details on the tag or in the catalog listing tell you more than the photo does: the grade, whether the plant is grafted or on its own roots, and the hardiness rating.

What does grade mean on a rose label?

Grade 1 is the heaviest plant, with the most and thickest canes. Grade 1½ and Grade 2 are smaller and lighter, and cost less. A Grade 1 bare-root plant carries more stored energy into its first winter, so it is the better pick for a cold site. A Grade 2 plant can still grow into a good rose, but it has less margin when the weather turns hard. Potted roses are rarely graded the same way, so judge them by the number of firm green canes and the firmness of the root ball.

Why does own-root matter more the colder it gets?

A grafted rose is a cutting of the flowering variety joined to a rootstock, and the join shows as a knob at the base of the canes. If a hard winter kills the plant to the ground, whatever regrows from below the graft is the rootstock, which is usually a wild-type rose with small, single flowers. An own-root rose has no such risk, since every shoot from the roots is the rose you bought. In zone 6b and 7a, a grafted plant can usually be mounded and saved. In 5b the odds of dying to the graft go up, so choose own-root plants and check the tag or listing for the words “own root.” Finally, trust the zone number on the tag only when it reads 5 or lower, and be skeptical of a broad range that starts at a warmer number.

Checking this against your own county

A state is too big for one answer, and a zone map smooths over low spots, hilltops and town heat. Purdue Extension has an office in every Indiana county, staffed by educators and Master Gardener volunteers who know which roses have lasted in local yards. Call your county Extension office with your address and the rose you are considering. Ask what the winter low has been in recent years, whether the soil drains, and which cultivars have lived on neighboring properties. A ten-minute call often beats an hour of catalog reading.

Common questions

Is Knock Out rose hardy in Indiana?

In zone 5b it may lose cane tips or even half its height in a cold winter, but it regrows from the base and still blooms the same year. Trim dead wood back to green tissue in spring.

Do rugosa roses need winter protection?

No. Hansa and Therese Bugnet take colder winters than any Indiana zone delivers. Skip the mounding and wrapping, and save the effort for roses that need it.

Can I grow a hybrid tea in northern Indiana?

You can, with a commitment. Mound soil over the graft union each fall, expect some cane dieback, and accept that a few plants will die. An own-root hybrid tea is a safer bet, since a freeze that kills the canes will not turn it into a different rose.

Why did my rose come back as a different rose?

The plant was grafted and the graft died in winter. What grew back came from the rootstock below the union. The original variety is gone, and replacing it with an own-root plant avoids a repeat.