- Author: Barbra Pushies
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.
- Author: Lauren Fordyce
It may be after Labor Day, but some of your plants may still be wearing white, breaking that long-standing fashion “rule”! While many of us don't adhere to this old rule for our wardrobes these days, you may care about white stuff on your plants this time of year.
There are several white colored pest insects and diseases that you could be noticing on your plants.
Scales
Several types of scale insects are white. Each has their own host preferences, or plants they feed on.
- Cochineal scales feed only on cacti, usually prickly pears. On the outside they are white and waxy but have bright red bodies. If you scrape them off, you'll notice a red stain left behind.
- Cottony cushion scale feeds on a variety of woody ornamental plants. Common hosts in California are citrus, cocculus, nandina, and pittosporum. Adult scales are elongated and fluted.
- Euonymus scale feeds on many different plants but can be a serious pest to Japanese Euonymus (Euonymus japonica). Immature males are white and elongated with a brownish-yellow area at one end.
See the UC IPM Pest Notes: Scales to learn more about these and other scales and how to manage them.
Mealybugs
Mealybugs are whiteish-gray, oval, wax-covered insects. They can be found on many different plants, from fruit trees to houseplants, often hiding in protected places like branch crotches.
Powdery mildew
Powdery mildew often appears as white powdery spots (fungal spores) primarily on the tops of leaves. It can infect fruits and fruit trees, vegetables, and landscape plants in shady conditions when temperatures are between 60 to 80 degrees.
Whiteflies
Whiteflies are tiny insects with white, waxy wings and yellow bodies. They feed in large colonies on the undersides of leaves and have a very wide host range, including trees, vegetables, houseplants, and flowers.
Hackberry wooly aphids
This introduced aphid species infests Chinese hackberry and other hackberry (Celtis) plants. Hackberry wooly aphid adults appear in white, fuzzy masses on shoot terminals and leaves.
Spittlebugs
Adult spittlebugs are often brown, but they produce a white, foamy excrement on plants that looks like spit. They are known to feed on just about any plant.
Mushrooms
Many fungi produce white fruiting bodies that may pop up in your lawn, mulched landscape beds, or on trees and stumps. Puffballs and other fungi in lawns are mostly just a nuisance. However fungi on trees can sometimes cause wood decay and harm trees.
For more help diagnosing a plant problem or identifying a pest, see the UC IPM Plant Problem Diagnostic Tool or contact your local UC Master Gardeners.
- Author: Sherida Phibbs
There is a section of this rose bush where the new spring leaves are small, yellowed and odd shaped. The shoots are stunted and narrow. Also, malformed flower buds are present.
This is a typical symptom of phytotoxicity. After further investigation, it is determined that the during the prior summer and fall seasons, glyphosate was used to eradicate bindweed 3 feet from the rose bush. Roundup, a common glyphosate was used. Roundup is one of hundreds of garden products that contain glyphosate.
Roses are extremely sensitive to glyphosate as well as various postemergence broadleaf herbicides. Drift from herbicide spray lands on the leaves and stems, creating herbicide damage. For roses, there is no quick cure. Only time, loving care and the wait and see approach is all one can do. The bushes are stressed and weakened, some will recover and there is always the chance that some may not. Rose bushes may be compromised for years and will never have the vigor they once had.
Lawn weed-and-feed products may also create herbicide toxicity in roses. Herbicides can be taken in through the stem and leaves by direct application or by drift, as well as intake through the roots. Bottom line, extreme care should be taken when using toxic products, for the safety of humans, wildlife, pets and plants. Always read the labels and follow the directions for using and discarding any pesticide.
Additional information on herbicide damage can be found here.
The UC IPM pest notes on Roses Cultural Practices and Weed Control can be found here.
- Author: Kathy Keatley Garvey
Lady beetles, aka ladybugs, are not the only insects that feed on aphids.
So do the soldier beetles, family Cantharidae. They are sometimes known as leatherwings.
Got roses?
Got aphids?
You may also have a good friend, the soldier beetle.
Wikipedia tells us that their color pattern is reminiscent of the red coats of early British soldiers.
True.
- Author: Kathy Keatley Garvey
"The Redcoats are coming! The Redcoats are coming!"
So shouted American Revolutionary patriot Paul Revere during his historical ride. Those who responded to the colonial revolt included my immigrant ancestors: the Keatleys, Laughlins and Agees.
They left their farms and took up arms.
Today, July 4, we celebrate Independence Day, remembering the American patriots from the 13 colonies that defeated the British during the American Revolutionary War, 1775-1783.
Wonder what life was like back during that time?
They grew vegetables and other crops; raised chickens, pigs, dairy and beef cattle and animals; hunted deer, elk and other game; and fished the nearby rivers and oceans. Their menu included eggs, milk, venison, bacon, bread, potatoes, fish, and rice.
And honey. Yes, they raised bees.
European colonists brought the honey bee (Apis mellifera) to the Jamestown colony (Virginia) in 1622. The native American Indians called it "the white man's fly." In 1853--231 years later--honey bees reached California. A beekeeper brought the insects here in the middle of the California Gold Rush, 1848-1858. A plaque outside the San Jose Airport heralds their arrival.
In looking through my images of honey bees for this traditional Fourth of July Bug Squad blog, I found two that are especially suitable: Four bees sharing a single blossom.
- Four on a rose
- Four on a pomegranate
May the Fourth Be With You!