Posts Tagged: pruning

Pruning Roses and Cultivating Beauty

Pruning roses is not just a chore; it's an important practice for nurturing vibrant, healthy roses and fostering the beauty of your garden. In California, where the climate is favorable for growing roses, understanding the significance of pruning is key to achieving thriving and healthy roses.

 

Why Prune?

Pruning isn't merely about maintaining a tidy appearance; it's about promoting the overall well-being of your roses:

• Annual pruning stimulates plant and shoot growth, leading to larger blooms and a more robust structure.
• Removing dead, damaged, or diseased canes minimizes the risk of fungal infections and pest infestations, fostering plant health.
• Thinning out dense growth improves air circulation within the plant, reducing the likelihood of fungal diseases like powdery mildew and black spot.
• Shaping the plant through pruning enhances its visual appeal, creating a more attractive landscape.

When to Prune

Timing is important when it comes to pruning roses. In California, where winters are mild, the ideal time for pruning is typically between late winter and early spring. Pruning during dormancy allows the plant to focus its energy on new growth when spring arrives.

How to Prune

Pruning may seem daunting, but with the right approach, it becomes a manageable task:

• If the plant is dormant (recommended), remove all remaining leaves.
• Use sharp, clean pruning shears and loppers to make precise cuts, minimizing damage to the plant.
• Trim back old growth by about one-third to improve visibility and encourage new growth. Remove dead, diseased, or crossing canes to maintain a healthy structure.
• Make pruning cuts approximately ¼-1/2” above an outward-facing bud.  Pruning cuts should be at a 45-degree angle, sloping away from the outward-facing bud.
• Create an open, vase-like shape by removing canes from the center of the plant. This promotes airflow and sunlight penetration, which is essential for plant health.
• Clear away debris and old leaves to prevent disease spread. Consider applying insecticidal soap or horticultural oil during dormancy to control pests.

 

Conclusion

Pruning roses is a fundamental aspect of rose care that should not be overlooked. By understanding the importance of pruning and following basic pruning principles, you can nurture thriving roses that add beauty and vitality to your garden year after year. For more details on growing roses and pruning timelines for your area contact your local UC Master Gardener Program.

 

Wise Words on Pruning

From Tim Spann, Spann Ag Research & Consulting

Use Sharp Tools in order to make Clean Cuts

Follow 3-Cut Method for larger branches

Whitewash with more extensive pruning

Watch the Weather

And Don't Apply Pruning Paint

READ it Here, and Hear

 

Pictured: 3-Cut Method

 

pruning

Almond growers should prepare for possibility of unusual disease outbreak

Wet winter, El Niño create favorable conditions for aerial Phytophthora pathogen

With heavy rains in the forecast amid strengthening El Niño conditions, almond growers should be on the lookout for a rare disease that can cause severe damage to their orchards, according to Florent Trouillas, a University of California Cooperative Extension specialist in fruit and nut pathology.

Phytophthora, soilborne microorganisms dubbed “water molds” because of their dependence on water, typically cause root and crown rot at the base of trees. But a few aerial Phytophthora can travel upwards and infect the higher parts of the tree. One species – Phytophthora syringae – is drawing special attention due to an unprecedented outbreak last winter, fueled by the atmospheric rivers that lashed California.

“It was found statewide – meaning in every almond-producing county – and disease incidence in orchards ranged from 10% of the trees infected to 75%,” said Trouillas, a UC Davis plant pathologist whose lab is based at UC Agriculture and Natural Resources' Kearney Agricultural Research and Extension Center in Parlier.

Trouillas and his colleagues, UC Davis graduate student Alejandro Hernandez and UC Riverside plant pathology professor Jim Adaskaveg, recently published a detailed online article describing the pathogen, which can infect a range of crops but mainly impacts almonds in California.

Although it doesn't kill the tree, the disease causes branch dieback that requires significant additional work and expense for almond growers. In 2022, almonds were the state's fourth-highest valued commodity, at $3.52 billion.

During last year's aerial Phytophthora outbreak, researchers also observed a new and troubling phenomenon: P. syringae, historically known to attack the cuts caused by pruning, was directly infecting the young shoots on almond trees – without any wounds.

“This was really the first time we had seen widespread evidence of infection on the twigs,” Trouillas said.

Although generally rare, outbreaks of P. syringae have been traditionally associated with wet El Niño years, according to Trouillas – and recent and persistent rain across the state should have growers on high alert.

Prune in dry weather, monitor, mitigate if necessary

While almond growers tend to prune during the downtime of winter, they should keep an eye on the forecast and aim for a 10- to 14-day window of dry weather to perform those tasks, whether training young trees or maintaining the established ones.

“If growers were to prune around a rain event – before, during or shortly after – this increases the likelihood of infection because this pathogen moves around with water,” Trouillas explained.

Researchers speculate that P. syringae, normally found in the soil, gets carried into the upper parts of a tree through strong winds and heavy rain. Alternatively, harvest processes like shaking and sweeping also produce air movements that may blow the microorganism into the canopy, where it waits for a favorable wet environment. The pathogen then attacks the wounds or young shoots, producing characteristic cankers and gumming.

The patterns and colors of the gum balls are keys to diagnosing an infection of this particular aerial Phytophthora. Starting around bloom time (mid-February), growers should monitor pruning wounds and young shoots on their trees, especially in the canopy, for signs of the disease.

The unique coloration of the gum balls – ranging from gold and amber to dark burgundy to bright red (see photos) – generally indicates P. syringae infection. But growers are urged to contact their local Cooperative Extension advisor for confirmation.

“It is super critical for growers that, whenever they see gumming, not to assume that it is this aerial phytophthora, because there are many other diseases that can cause gumming on the tree,” Trouillas said.

If the diagnosis is confirmed, growers may apply a compound that can mitigate the infection. The plant pathologists' recent writeup describes several curative treatment options, as well as a preventive measure that reduces the amount of pathogen in the soil and thus the likelihood of infection.

For more information on the pathogen's history and biology, as well as various options for disease management, visit the article on Sacramento Valley Orchard Source: https://www.sacvalleyorchards.com/almonds/trunk-soil-diseases/aerial-phytophthora-outbreaks-in-wet-years.

Do I Really Need to Prune My Roses?

The answer is YES! And it is easy!

If you prune, your rose flower bushes will
• Be larger
• Have more flowers
• Will be more balanced and fuller
• And the health of your plant improved!

Most roses need to be pruned only once a year. All types of rose bushes benefit from pruning and if roses are not pruned regularly, they deteriorate in appearance and flowers will become smaller.

When to Prune?
Most roses should be pruned when they are dormant. In this area of California, roses are generally dormant between December and February and anytime in that time frame is fine.

Objective
The pruning objective is to work toward an open, airy, well-shaped and balanced V-shape cane structure.

What you will need
• A pair of sharp, clean pruning shears
• A pair of clean long-handled lopping shears
• Thick gauntlet gloves to protect your hands from the thorns
• A small hand saw for larger cuts
• Alcohol and a cloth for cleaning your tools

How to approach the task
These pruning practices pertain to all garden roses regardless of type:
• Use your loppers to cut off the top one third to one half of the plant to better see its structure.
• Clear the area underneath the plant from all leaf and other organic debris to expose the crown/canes and sucker origins.
• Make your pruning cuts with your shears at a 45 degree angle about 1⁄4” above an outward facing bud. The angle should slope away from the bud. A cut made at this point will heal rapidly and water will drain away from the bud.
• Remove all dead, broken or damaged canes down to the crown.
• Undesirable canes have discolored pith or hollow centers indicating disease, insect or weather damage.
• Remove any crossing canes keeping the best looking ones.
• Remove spindly canes (smaller in diameter than the size of a pencil).
• Remove any suckers. These are extra vigorous shoots arising from rootstock below the bud union.
• Suckers should be removed completely, not just clipped off where they emerge from the soil. This can be done by moving the soil away from the trunk until you can see where the sucker is connected to the trunk. Grab ahold of the sucker close to the trunk and pull downward to break it off.
• Choose 3–6 strong, healthy, outside canes per plant to keep and leave 3–5 buds on each cane.
• Remove EVERY leaf from the newly pruned bush as diseases and insects tend to over winter in old leaves.
• Consider applying an insecticidal soap or horticultural oil after pruning and while roses are dormant. Soaps and oils smother overwintering scales and insect eggs and are least harmful to beneficial insects. A good time to apply is when no rain or fog is expected within a day.
• Shape your rose bushes as they grow. Keep the branches balanced and the centers open for airflow.

General pruning techniques for various types of roses
Hybrid Tea, Grandiflora, and Floribundas Roses
• Cut back between one third and one half of the previous year's growth on all the canes you plan to keep (4 to 7 canes). The average pruning height for Floribundas and Hybrid Teas is between 12 and 18 inches, but taller growing Hybrids and most Grandifloras may be left at 2 feet. For most hybrids this means leaving between 5 to 10 buds per cane.
Miniatures Roses
• Miniature roses are 6 to 12 inches high, with tiny blooms and foliage. Miniature roses do not need special pruning. Just cut out dead growth and remove the hips.
Rambler Roses
• Old-fashioned Rambler roses have clusters of flowers, each usually less than 2 inches across. They often produce canes 10 to 15 feet long in one season. Rambler roses produce best on one-year-old wood, so this year's choice blooms will come on last year's growth. Prune immediately after flowering. Remove some of the large old canes. Tie new canes to a support for the next year.
Climbing Roses
• Large-flowering climbing roses have flowers more than 2 inches across, borne on wood that is 2 or more years old. Canes are larger and sturdier than those of Ramblers. Many flower just once in June, but some, called ever-blooming climbers, flower more or less continuously. Often this group is pruned in the autumn, any time before cold weather sets in. First cut out dead and diseased canes. After this, remove 1 or 2 of the oldest canes each season to make room for the new canes. The laterals, or side shoots, are shortened 3 to 6 inches after flowering. If the plant is strong, keep 5 to 8 main canes, which should be tied to the trellis, fence, wall, or other support. If it is not strong, leave fewer canes.

Link for rose pruning video: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=16947

See this UCIPM site for more information on rose care:
https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/rose.html

Help Desk of UC Master Gardener Program of Contra Costa County (PDS)

 

Espalier Gardening

There is a bit of ancient Rome and a taste of old Egypt at the Master Gardener Demonstration Garden at the Patrick Ranch. Butte County MGs are practicing espaliering, the early horticultural art of training and pruning a tree or shrub to grow flat...

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