Spring flowers are a nice thing. Maybe seeing bright colors after a drab winter is the reason that spring flowers are so memorable. But right now I am enjoying fall flowers…. Goldenrods (Solidago), Asters (Aster) White-snakeroot (Eupatorium rugosum) and Beggar-ticks (Bidens) are just a few of the beauties that are blooming now. September is a good time to appreciate them. Fall leaf color is not competing for our attention yet.
I had to get out my plant references to identify the White-snakeroot that is blooming (white) along the 611 bypass near Danboro. It wasn’t in “Weeds of the Northeast” so I went to “The Plants of Pennsylvania”. I like “Weeds of the Northeast” because it lists several hundred common weedy plants and has lots of color pictures. “The Plants of Pennsylvania” doesn’t have color pictures but lists several thousand species! It helps to have a rough idea of what you’re looking for when consulting it. So, as I was researching the White-snake root I learned that there are 18 Euparoriums, 45 Asters and 26 Solidagos in Pennsylvania.
Besides the colorful show that fall blooms provide, many of them provide forage for insects, including honey bees. If you are near a bee hive in September, the fragrance of goldenrod and aster nectar is unmistakable.
If you enjoy identifying local flora, the two books I mentioned are excellent references. You can find both of them at on-line book sellers.
Bowman's Hill Wildflower Preserve in Washington Crossing, PA is offering guided wildflower walks this fall, daily at 2 p.m. for a small fee. A great way to learn the names of more fall bloomers.
Wednesday, September 24, 2008
Tuesday, September 16, 2008
Powdery Mildew Appears
What’s that white stuff on my…. you name it….zinnias, lilac, pumpkin, dogwood. It’s powdery mildew, a common fungal disease that appears in late summer every year. Yes, it is a disease but there is no need for alarm. In most cases, it’s just cosmetic.
Actually, there are many different, related fungi that cause symptoms that we call powdery mildew. While related, in most cases they are specific to their host plants. For instance the powdery mildew on apple is not that same as the organism that affects lilac.
Commercial growers of pumpkin, apples, peaches and some other crops must manage powdery mildew or serious crop damage can occur. In backyard gardens, we can usually accept this damage caused by the disease. All deciduous plant leaves are due to drop in the next month so, powdery mildew or not their days are numbered.
Bottom line, don’t worry about powdery mildew. For a more complete story on this common disease see what Cornell University has to say.
Don’t worry about putting mildew infected leaves into the compost. Next year’s infections will come from many sources and the fungus will probably have trouble surviving the compost pile environment anyway.
Actually, there are many different, related fungi that cause symptoms that we call powdery mildew. While related, in most cases they are specific to their host plants. For instance the powdery mildew on apple is not that same as the organism that affects lilac.
Commercial growers of pumpkin, apples, peaches and some other crops must manage powdery mildew or serious crop damage can occur. In backyard gardens, we can usually accept this damage caused by the disease. All deciduous plant leaves are due to drop in the next month so, powdery mildew or not their days are numbered.
Bottom line, don’t worry about powdery mildew. For a more complete story on this common disease see what Cornell University has to say.
Don’t worry about putting mildew infected leaves into the compost. Next year’s infections will come from many sources and the fungus will probably have trouble surviving the compost pile environment anyway.
Wednesday, September 10, 2008
Budworms ate my blossoms
Penn State Master Gardeners have established several fantastic demonstration gardens at Neshaminy Manor Center, where our Extension office is located. We recently received the Pennsylvania Horticulture Society “Community Greening Award”.
But there is trouble in paradise. The tobacco budworm has eaten virtually every blossom and flower bud from our petunias! Purple ones, white ones, pink ones. We knew what was up because this is a recurring problem. Initially, we thought that the petunias simply stopped blooming but on closer inspection it was easy to see the chewing damage. Once we caught one of the caterpillars it was easy to solve the mystery.
Several weeks ago we applied Bt, (Bacillus thuringiensis) a biological insecticide, and that did the job. We must be into the next generation of budworms now because the color is again gone from our petunia beds. The Bt treatment only lasts a short time.
So, if your petunias (or geraniums or tobacco)seem to have mysteriously stopped blooming, check the flower buds for ragged, chewing feeding symptoms. The insects themselves are elusive, feeding at night and hiding during the day. A shot of Bt did the trick for us. Other insecticides will work but Bt is quite selective for caterpillars and so that is a good choice.
But there is trouble in paradise. The tobacco budworm has eaten virtually every blossom and flower bud from our petunias! Purple ones, white ones, pink ones. We knew what was up because this is a recurring problem. Initially, we thought that the petunias simply stopped blooming but on closer inspection it was easy to see the chewing damage. Once we caught one of the caterpillars it was easy to solve the mystery.
Several weeks ago we applied Bt, (Bacillus thuringiensis) a biological insecticide, and that did the job. We must be into the next generation of budworms now because the color is again gone from our petunia beds. The Bt treatment only lasts a short time.
So, if your petunias (or geraniums or tobacco)seem to have mysteriously stopped blooming, check the flower buds for ragged, chewing feeding symptoms. The insects themselves are elusive, feeding at night and hiding during the day. A shot of Bt did the trick for us. Other insecticides will work but Bt is quite selective for caterpillars and so that is a good choice.
Tuesday, September 9, 2008
Thanks, Mother Nature
Ah rain. Until Hanna delivered a few inches last weekend, we were in a drought. What’s a drought ? The National Weather Service says an agricultural drought refers to a situation where the amount of moisture in the soil no longer meets the needs of a particular crop.
The effects of drought on annual garden plants such as vegetable and flower gardens are obvious. Certainly the needs of these plants were not met as August yielded less than an inch of rainfall in most of Bucks County….less than half and inch in my neighborhood. But what concerns me more is the long term effect of drought on perennial plants, especially trees. For the last two weeks I’ve observed severe stress symptoms on many trees and shrubs. They will revive and survive but in many cases this stress will lead to disease and failure in years to come. Penn State’s plant disease clinic receives many plant samples each year and has correlated the incidence of drought and certain diseases of woody plants, especially botryosphaeria canker on rhododendron, dogwood, redbud and crabapple and cytospora canker on spruce. These diseases lead to severe branch cankering and dieback.
During the drought of 1999, which was extreme, I observed stress on many woody plants that lead to plant decline and death in the years that followed. Here at Neshaminy Manor Center, home of the Almshouse Arboretum, we watered trees that were planted in 2007 and 2008 to insure that they will thrive in years to come.
The effects of drought on annual garden plants such as vegetable and flower gardens are obvious. Certainly the needs of these plants were not met as August yielded less than an inch of rainfall in most of Bucks County….less than half and inch in my neighborhood. But what concerns me more is the long term effect of drought on perennial plants, especially trees. For the last two weeks I’ve observed severe stress symptoms on many trees and shrubs. They will revive and survive but in many cases this stress will lead to disease and failure in years to come. Penn State’s plant disease clinic receives many plant samples each year and has correlated the incidence of drought and certain diseases of woody plants, especially botryosphaeria canker on rhododendron, dogwood, redbud and crabapple and cytospora canker on spruce. These diseases lead to severe branch cankering and dieback.
During the drought of 1999, which was extreme, I observed stress on many woody plants that lead to plant decline and death in the years that followed. Here at Neshaminy Manor Center, home of the Almshouse Arboretum, we watered trees that were planted in 2007 and 2008 to insure that they will thrive in years to come.
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What's blooming? What's chewing on my trees? What's that bug? When is the last frost? We'll explore timely horticultural happenings and observations of Nature in this blog. For the most part, these observations will be made in Southeastern Pennsylvania... with occasional notes from afar.Penn State Extension has tremendous resources related to much of what will appear here. I'll link you to sites that will provide more in-depth information.
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