I have inherited a house with many beautiful, mature and antique climbing roses that go up to the roof. I need to get the house painted and must trim the roses way back.

How can I safely do that so that they won't die or become diseased because of the trauma? How far back should I trim them? (The painter would prefer 1-foot stubs.) I don't think the stems are very flexible, so leaving them long and bending them away from the house may be an option only for some.

– Lisa Heschong, Fair Oaks

Established roses are as tough as nails, said UC Master Gardener Bill Pierce. Cutting them to 1-foot lengths would be a good way to renew the plants.

If you do this, give each of them about a half-cup of rose food fertilizer this month. Each plant will send up several new canes with roses on the ends of the canes.

These new canes should be trained on a trellis; tied in a fan shape is best. Blooms will develop at the end of each cane, and lateral shoots will develop on these canes.

The shoots will rebloom for several seasons. When a shoot fails to produce new blooms, or the cane is no longer producing new laterals, it is time to remove it by cutting it at ground level.

In future years, renew your bushes by removing one or two old canes every year and let the bush replace them by developing the new ones that grew in the previous season. This pruning should be done in January on most varieties, but some rose species prefer to be pruned in the spring after their bloom.

If you follow the schedule for fertilizer application that is printed on the rose food bag, your plants should produce plenty of new canes, probably more than you will want to keep.

The Historic City Cemetery at 10th Street and Broadway in Sacramento is a good source for pruning your antique roses. Visit its website at www.oldcitycemetery.com for information on hours and events.

The cemetery's Heritage Rose group (www.cemeteryrose.org) will host its annual open garden day April 16. At that event, you can ask experts about the pruning and care of old garden roses, and identify some unknown roses.

My rosebushes have developed a large number of thorns. Is it possible to reduce the thorns on the stems?

– Dave Deubner, Citrus Heights

According to UC Master Gardener Amelia Murray, your rosebushes were genetically programmed to grow thorns (called "prickles" by the rose community).

Rose prickles are usually downward-pointing, sickle-shaped, woody projections growing between bud nodes on the stem. The purpose of prickles is to protect the rose petals and the plant from predators, such as deer and rodents, which love to eat roses.

You may have noticed that some roses are thornier than others. This is also genetic.

You can remove the prickles by gloved hand when the cane is young by gently pushing on the side of the prickle.

Also, you can remove prickles from cut stems with a dethorning tool. Lightly drag the dethorner down the stem; the prickles should pop right off.

Rose prickles can be removed with a sharp floral knife or paring knife. Because rose prickles can carry a fungus – Sophorix shenckii or "rose thorn disease" – on their tips, always wear protective gloves when working near and on roses. Also, prickles may become embedded in your skin, which makes prevention the best and safest action when handling roses.

© Copyright The Sacramento Bee. All rights reserved.