The official blog of the Oregon State University Plant Clinic
The chemical stew of black spot
The intermittent rainfalls this spring in Western Oregon have been a bonanza for fungal diseases, and many are showing up earlier than we have seen [...]
Snow-making bacterium is making no friends
The same bacterium used to make artificial snow, Pseudomonas syringae, is causing problems in blueberries right now. The near freezing night time temperatures experienced [...]
Carpet Beetles
Series: Insects commonly submitted to the OSU Insect ID Clinic While you’re sheltering in place at home right now, you’re probably noticing some [...]
Brown rot – an aptly named and unwelcome disease of stone fruits
I have a sour cherry tree in my yard that declines a bit more each year. It is in sad shape, with seared-open main branches injured by sun scald and invaded by decay fungi. This all stemmed from leaf loss due to an ongoing and pervasive case of brown rot caused by the fungus Monilinia. This organism infects first through the flowers, usually after a rain while the flowers are open.
Tea Scale: An unwanted hitch-hiker
Sunny days and warmer weather bring about thoughts of gardening: which plants are not performing as well as would be liked, which new ones would look better in that spot. If you are contemplating adding to your garden, be sure not to add an unwanted component: insect or mite pests (or disease) that might be tagging along with your new acquisition.
Pest and Weather Models
The Oregon Statewide Integrated Pest Management (IPM) Center has a great collection of online resources to support both commercial growers and home gardeners across the country. Their web-based tools include weather and climate driven models for IPM/pest models, plant disease risk models, crop models, horticultural models, beneficial species models, climate suitability models, and many others.
The spotted lanternfly makes its first west coast appearance
Last September we published our first post about the potential for the spotted lanternfly, Lycorma delicatula, to be a pest of serious concern to Oregon agriculture. At the time, only a handful of eastern states had reported established populations (Pennsylvania has been the most impacted). More recently, a live adult spotted lanternfly was reported in Davis, California.
We’ve moved! (And How to Find Us)
Cordley Hall is preparing for a major renovation, and while we wait for brand new lab and office spaces, we've relocated upstairs on the [...]
Hide your honeybees, the Asian giant hornet has landed in the PNW
The New York Times just published (5/02/2020) an updated article about the Asian Giant Hornet titled ‘Murder Hornets’ in the U.S.: The Rush to [...]
Purple days
Winter is the perfect time for dreaming of the perfect garden.Even if your garden is established, it is never really finished. Preferences change over time. [...]
Baby it’s cold outside
The forecast for the next few weeks is cold – the first severe cold temperatures we have seen in western Oregon this winter. It may be a good time to review how plants are damaged by freezing weather.
Secretary of War brings back the flower of peace
The association of poinsettias with Christmas is said to have begun over 500 years ago. The plant has been growing in dry tropical forests, along the Pacific coast from Mexico to Guatemala, for even longer than that. In its native form, it grows as a lanky, long-stemmed small tree or large bush. The wild plant has brilliant red “flowers”, but the red bits are narrow, less eye-catching, and scarcely like those on the plants we see in garden centers.
Garlic Gone Bad – Part II
Part II to our series! Here are more common problems you might encounter in your summer-grown garlic.
Garlic Gone Bad
Winter is the time to use your summer-grown garlic. Fortunately, we have great garlic-growing weather here in Western Oregon, although occasionally problems do arise. This week we are showing some common problems that can pop up and which are usually only found when you are cracking those heads, seeking the perfect cloves for your favorite potato and garlic soup.
Calling all naturalists!
Our fun Friday feature is a short introduction to a really cool app called iNaturalist. iNaturalist is essentially an online social network of enthusiastic naturalists, citizen scientists, students, researchers and experts who provide a worldwide crowdsourcing species identification system. Record your own observations, get help identifying species you record, and join projects that can use your observations for research or education efforts. Take your smart phone into your backyard or out on a hike, and try recording your first observation.
Governed by Micrometeorology: Apple Scab and Spore Dispersal
Apple scab, that fungal disease known to just about anyone who had grown an apple, can convert a promising young fruit into a disfigured, unappetizing reject. Although safe to eat, in this day of readily available perfect fruit, we would rather do without scabby fruit.
Propagation pitfall: Leafy gall disease
Now is the time when nurseries are propagating plants for the upcoming spring season. Odd looking plants with too many shoots or buds could be infected with the pathogenic bacterium Rhodococcus fascians. Propagators should be alert for symptoms, as shown in the gallery below, and have suspicious plants tested for the presence of the bacteria.
Giant House Spiders
We shared a post about a similar (Hobo) spider earlier this year, but that might not be the only oversized arachnid housemate you encounter this fall.
Don’t wait! There is a reason they call it boxwood blight
Boxwood blight is a relatively recent disease that is devastating Buxus plants on the east coast, and which has made limited inroads in Oregon.
Cannabis aphid
The cannabis aphid is a pest aphid found on the leaves and stems of cannabis. Aphids have "piercing-sucking" mouthparts to feed on plant fluids. When aphids occur in high numbers, their feeding can stress plants and cause wilting, yellowing and other damage. Cannabis aphids are also potential vectors of plant pathogens.
Jerusalem crickets (no relation to Jiminy)
Jerusalem crickets seem to fascinate those who find them. Also known as potato bugs, devil’s babies, and niña de la tierra (child of the earth), they are members of the genus Stenopelmatus and are related to katydids and cave-dwelling camel crickets.
Great Expectations
Plants require soils that allow their roots to exchange oxygen with the soil, soils in which their roots can expand and grow, and that have adequate moisture retention capability. Trees surrounded by paving have limitations to all these necessary conditions.
Asian Gypsy Moth
The Asian gypsy moth (AGM) is an exotic pest that is considered a potentially serious threat to North American forests. It is a close relative of the European gypsy moth, which is well-known for causing widespread damage in eastern US forests.
Botrytis on hemp… it’s in the news!
The weather this fall has been ideal for development of molds (like Botrytis) in the tight colas of the hemp plant. The alternating cool and moist weather followed by a few clear days of moderate temperatures have been perfect for the moisture-loving fungus. Which translates to bad news for the growers, who depend on the flowers for their CBD-related products.
A tangled tale
The practice of making a planting hole with an auger and stuffing in a young plant can cause problems as the plant grows. Although handy [...]