Transplanting roses in the ‘wrong’ season

We are moving from one home to another this summer. We have a rose bush in our garden that was a gift for a special occasion that we planted about three years ago, and we’d like to take it with us. Is it possible to transplant a rose bush? It’s not very large, but it has a few blooms on it now.

The best times to transplant roses are in early spring or in the fall, but if, for whatever reason, mid-summer is when you have to do it, then give it the best care possible. Here is advice from Marty Reich, a consulting rosarian with the Nashville Rose Society and American Rose Society:

Winterize your roses

I’ve heard gardeners talk about “winterizing” roses. What does that mean? And how do you do that?

Winterize rose shrubs to prevent damage from cold and wind.

If you live in an area that experiences intense cold or cycles of freezing and thawing, you may have heard about the importance of winterizing your roses. While rose shrubs are generally hardy, some varieties may be vulnerable to extended cold weather and strong winter winds. “Winterizing” helps protect roses from winter damage.

The process begins in late summer. You should discontinue fertilizer applications about mid-August, to slow down new growth. Stop cutting off the dead blooms in early October, which signals the plant to stop producing new growth.

Now comes the important “winterizing” part: Between now (late November) and mid-December, cut the canes back to 2 to 3 feet tall to keep them from blowing around in the winter winds, loosening the soil around the roots. Rose experts at the Nashville Rose Society suggests placing a 12-inch high mound of soil or mulch around each bush. To minimize winter damage at the end of each cane, you can also erect a small cage of chicken wire around each bush and pile about two feet of hay or other loose organic material inside.

Miniature roses and others grown in containers can be moved to an unheated garage or other space where the temperature remains above 20 degrees. Plants should be watered just enough to keep them moist.

For advice on roses in Middle Tennessee (where The Garden Bench calls home), I usually turn to the rosarians at the Nashville Rose Society, who provide excellent information on growing roses at their website. We are in USDA Hardiness Zone 7a, and the schedule reflects normal conditions in our climate. Gardeners in colder areas may adjust accordingly.

Rose enthusiasts can also get information (and see photos of beautiful blooms) from Birmingham, Alabama-based rose expert Chris VanCleave aka “The Redneck Rosarian.” He writes about roses, hosts podcasts, and keeps the conversation going with #RoseChat on Twitter.

Roses may be at risk for fungal disease

My rose bush is developing little black spots on some of the leaves. What’s causing this, and what can I do about it?

Roses may develop diseases that affect the foliage.

For questions on roses, I always go to the helpful experts at the Nashville Rose Society, and their Web site. It looks like there are at least two fungal diseases that cause black spots on the leaves of roses: one appropriately called black spot, and the other, anthracnose. You can tell the difference by looking at the edges of the spots. Black spot has the feathery margins, which give rise to some of its other names: leaf blotch or star sooty mold.

Both make a rose look really bad for awhile, which is why people who are serious about growing fancy, beautiful roses stick to a rigid schedule of spraying. Fungicides are to ward off the ugly fungal diseases, pesticides to keep away chewing and sucking bugs.

Both blackspot and anthracnose overwinter on the plant and develop during a cool, moist spring. The best way to minimize the risk of developing diseases is with preventive maintenance: Clean up dead leaves and decaying matter around rose bushes, prune out diseased canes, make sure the rose bush is in a place that has good air circulation, and water in the morning, to give the foliage plenty of time to dry during the day. Fungicides, applied on a regular schedule in early spring, can help prevent infection.

Time to plant a rose

Question: We want to add roses to our landscape this year. When is the best time to plant them? Is it better to buy bare root plants, or plants in containers?

Roses purchased as bare-root plants can be planted in late winter, whenever the soil can be worked. In this area (USDA Hardiness Zone 7a), roses in containers should be planted after mid-April, say the experts at the Nashville Rose Society. Either should grow well and bloom if they’re given the right conditions: lots of sun – six or more hours a day – and good drainage.

Here’s how to plant roses to get them off to a good start:

Before you plant a bare root rose, soak it for 8 – 24 hours in a large bucket of water with root stimulator added. This rehydrates the plant. Dig a hole 18 inches wide and deep. Place ½ cup of superphosphate in the bottom of the hole, and cover it with a mound of soil made up of 1/3 top soil, 1/3 compost and 1/3 sand or perlite. Prune any broken or dead branches or old canes smaller in diameter than a pencil, and prune back any broken or unusually long roots.

Place the roots over the soil mound in the hole and spread them out and downward over the mound. Place the soil mix around the roots to fill the hole about halfway, and pour a gallon of water with root stimulant over the soil and let it drain. After this has soaked in, finish filling the hole up to ground level with soil mix. Cover the soil with mulch to help keep the bush hydrated until the feeder roots begin to grow; remove the mulch gradually as the weather begins to get warmer.

To plant a potted rose (after the last frost date in your area), dig a hole slightly larger than the diameter of the pot and about 18 inches deep. Place ½ cup of superphosphate or bone meal in the bottom of the hole and cover it with 2 inches of soil. Remove the bush from the pot without breaking the root ball (you may have to cut the sides of the pot away) and place the root ball in the hole so that bud union – the knot where the rose was grafted onto the root stock — is just above ground level.

Fill in around the root ball with soil, and water thoroughly with a bit of root stimulator added to the water.

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The Garden Calendar returns in The Tennessean and at Tennessean.com

In March, hope springs eternal in the garden

Too late to trim

Our Knockout roses and other shrubs really need one more trim before winter sets in. Is it safe to trim this late in the year?

Photo from Star Roses and Plants

The best time for shrub-trimming depends on what you have, but now that we’re rushing headlong into winter, it may be best to wait a few more weeks — until late winter or early spring — to take the shears to anything. If you have spring-flowering shrubs, especially, wait until after they finish flowering, to avoid cutting off the buds.

Rose experts generally say that the Knock Out rose varieties don’t need to be trimmed every year. Some garden specialists recommend removing about a third of the old branches every two or three years to encourage new growth. They can also be cut back to reduce the size of the plant. Whatever pruning or shaping you need to do, late winter is a good time for the task.

(Photo of the Knock Out® rose Rosa‘Radrazz’ is from Star Roses and Plants)

Spider mites like it hot. Watch your roses

QUESTION: What could be stripping the leaves off the branches of my roses? I spray with a product that is supposed to protect roses from insects and diseases, but it hasn’t helped.

Keep an eye on roses when it’s hot and dry. Spider mites can turn a lovely rosebush into an ugly mess.

This time of year, with this kind of weather, suspect spider mites, which thrive when the weather is hot and dry, say rosarians at the Nashville Rose Society. The tiny creatures get on the undersides of leaves and feed on the plant’s juices. The damaged leaves look speckled, turn yellow and fall off.

Spider mites are not insects; they are more closely related to spiders, so insecticides won’t have any effect. You can use a miticide, but it can be expensive. The best and cheapest way to control them is with a blast of water directed at the undersides of the leaves, rosarians say. If you do this every three days for a week or so, you break the mites’ gestation cycle.

Here’s a little more information about the tiny arachnids: Adult mites are less than 1/50 inch long. They use their mouthparts to pierce individual plant cells and remove the liquid. They produce webs that can coat the foliage with a fine silk that collects dust, making the leaves look dirty.

You can’t see them, but you can certainly see the damage. Heavily infested plants will be discolored, and if they are not controlled, the rose can be stunted, or even killed.

Record heat is trouble for trees

Meteorologist Bobby Boyd sends me email from time to time about extreme weather conditions. The latest concerns the large dome of high pressure building eastward out of the plains and across the Tennessee Valley that has put Middle Tennessee, as he says, “in the pressure cooker.” We’re breaking records this weekend. No rain in sight, and gardens are suffering.

Young trees and shrubs are especially vulnerable. The Nashville Tree Foundation has sent an alert with watering guidelines and new tips that you can read here to help trees survive.

Keep these tips handy. It’s still only June, and we’ve got a long way to go.

 

Best time to tame a rose

Question: When is the best time to prune roses? I have a bush that needs trimming, but don’t want to damage it by pruning at the wrong time.

If the rose is out of control, it won’t hurt to get out the clippers now. This advice comes from Annie Owen, a Master Rosarian and member of the Nashville Rose Society: “If the bush is overgrown, this is an okay time to prune it back, as long as it gets plenty of water.” In fact, if you reduce the size of the bush, you reduce its need for water, she said.

This goes for most types of roses, even those with finicky personalities and special fertilizing and spraying needs, as long as they’re healthy. If it’s a Knockout rose, no worries at all. “If it’s a Knockout, you can’t kill those things,” Owen said.

The Nashville Rose Society offers these pruning guidelines: Use sharp bypass pruning shears, which will make a clean cut without crushing the stem. Start by taking out older wood, along with any dead or dying canes. Remove any canes that rub or cross each other, or any twiggy, unnecessary growth. Make each pruning cut about ¼-inch above an outward-facing bud eye, where the leaf is attached to the stem.

Rose enthusiasts who winterize their prized roses will do more severe pruning in the fall. To begin the winterizing process, stop fertilizing roses now to allow the plant to slow down production of new growth. Early in October, stop cutting the dead flowers and leave the rose hips in place. In late November or early in December, cut the canes back to 2 to 3 feet, and place a mound of mulch around
the bush. This will hold them until spring, when you should prune lightly again to get new growth.

For general good advice on pruning and anything else that has to do with roses, visit the Nashville Rose Society’s Web site, www.nashvillerosesociety.com.

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It’s too hot to garden, but all is not lost over at Turning Toward the Sun.