BYGL-July 08, 2004

Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, Dave Goerig, Dan Herms, Tim Malinich, Jane Martin, Pam Sherratt, Amy Stone, and Curtis Young

July 08, 2004

This is the Fourteenth 2004 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension agents, specialists and other contributors in Ohio.
BYGL is also made available on the Internet from the Ohio State University Horticulture and Crop Science (HCS) in Virtual Perspective website (http://bygl.osu.edu). Additional fact sheet information on any of these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu).

BYGL is a service of OSU Extension and is aided by major support from the Ohio Nursery and Landscape Association (ONLA), with additional funding from the Ohio Chapter of the International Society of Arboriculture (ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT).

Participants in the July 06, 2004 conference included: Pam Bennett (Clark); Barb Bloetscher (Entomology and C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/South District); Jim Chatfield (North District/ Horticulture and Crop Science Department-HCS); Dave Dyke (Hamilton); Tim Malanich (Cuyahoga); Jane Martin (Franklin) Joe Rimelspach (Plant Pathology); Curtis Young (Allen); Nancy Taylor (C. Wayne Ellet Plant and Pest Diagnostic Clinic (CWEPPDC)); and Randy Zondag (Lake).

Additional factsheet information on any of these articles may be found through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)

WEATHER WATCH

Joe Boggs noted that the Cincinnati area is relatively dry; however, a recent rain event in parts of the area started to green things up. He reported that the recorded rainfall for the month of June is 0.34", just slightly down from normal; they are at +.21" for the year to date. Jane Martin reported that Columbus is all dried up! Their last significant rainfall was on June 13th with .55" of rain. They have had localized showers since. June rainfall was 5.34", which was +1.26. The year to date total for the Columbus area is 25.89", which puts them at +6.38 for the year.
Pam Bennett reported similar weather conditions in the Clark County area. She also reminded BYGLers that precipitation amounts are only relative to the site where the data was obtained. For instance, the OARDC Western Branch site outside of the city reported 3.5" of rain for June and +4.45 for the year. Another weather man within the city recorded 0.00" for June and +11.79 for the year. The additional amount was a result of 8.17" of rain in May.

HORT SHORTS

CORNELL'S VEG MD.

Now that the vegetable gardening season is in full swing, insect pests and diseases are also making their appearance and confounding gardeners. Of course, the first step in managing a pest is to identify it, and to that end, the Cornell University Department of Plant Pathology has developed a web site known as "Vegetable MD Online" that focuses on vegetable diseases. This site is searchable by crop or by photos and also links you to Cornell fact sheets on the various vegetable diseases. The photos assist in arriving at a diagnosis.

BUG BYTES

CONEFLOWERS DISTORTED

Purple coneflowers are an essential component of most perennial gardens. However, the flowers can be distorted by an eriophyid mite, reducing their value for use in indoor arrangements. These tiny, carrot-shaped mites live inside the opening flower buds and suck nutrients from the base of the flowers. As a result, both the disk flowers (the dark center) and the ray flowers (elongated purple petals) can become stunted, misshapen, or are absent entirely. The mites overwinter in the plant's roots and become active again in the spring.
There are various recommendations on controlling this pest. One is to rogue the planting, not replanting in the same area with coneflower, at least for several seasons. Infested flowers should be cut and removed from the garden; between cuts, dip pruners in an alcohol-based solution to clean them. Little can be done to treat this mite once the problem is noticed in a season, however, preventive systemic insecticides can help to reduce the incidence in following seasons. Treat in early spring as new growth begins using a systemic insecticide labeled for flowers.

CICADA MANIA CONTINUES

Just when we were beginning to think we would loose our hearing because of the on-going droning buzz of the periodical cicada, they died off along with their mating calls. However, now we are trading one buzzer for another. The ANNUAL or DOG-DAY CICADAS (Tibicen spp.) have emerged and started up their choruses of mating calls. Fortunately, there are fewer (LOTS FEWER) of these love-sick crooners singing their songs than were present in the areas with periodic cicadas.
Like their relatives the periodical cicada, annual cicadas also develop underground where the nymphs suck sap from plant roots. It may take two to three years for them to complete their development, but there are some adults emerging every year due to overlapping generations. Full grown nymphs emerge from the soil, crawl up a near by vertical surface, and molt to the adult stage. Emerging adults pull themselves out of the nymphal exoskeleton, expand their wings, harden their bodies, and fly off to find a mate.
Male cicadas attract female cicadas with their songs. Once mated, the females lay their eggs under the bark of twigs and stems of trees and shrubs. Newly hatched nymphs fall to the ground and burrow into the soil to find a food source and begin development toward the adult stage.
Cicada feeding causes little if any injury to the host plants. Some damage may occur from egg laying (oviposition). Because they cause little injury, controls are not recommended.

FIRE ANTS IN OHIO??

The CWEPPDC and Hamilton County Extension office have received several calls from alarmed citizens who claimed to have been bitten by fire ants. Upon questioning, they describe the ants as 1/8 - 1/4" long and red with black abdomens. The soil mounds in the yard can be several inches to 30" high and up to 13' wide. Several interconnected smaller mounds often surround the main mound. Armed with this description and the fact that fire ants are not established in Ohio, specialists have been able to advise that these are Alleghany mound ants (Formica exsectoides Forel), not fire ants.
Two fire ants can be found in the United states, the Southern fire ant (Solenopsis xyloni McCook) and red imported fire ant (Solenopsis invicta Buren). While the Southern fire ant ranges from California to South Carolina to Florida, the latter is found mostly in the southeastern states, but can be found as far north as Virginia. Most importantly, these ants will silently sneak en masse upon their prey and suddenly sting with an extruded "stinger" at the tip of its abdomen.
These excruciating stings can cause welts and scars. Allegheny mound ants tend to individually bite or pinch an object close to its nest or in the way, causing a sharp temporary pain. Since the ants are primarily beneficial in that they eat soft-bodied insects, it is usually recommended to leave the ants alone, but avoid planting shrubs or flowers near the home and sidewalks, patios, decks, etc. that attract insects. Few insecticides are labeled for outdoor applications to ant mounds, as people, pets and birds can be exposed to insecticides applied on top of the ground.

HAIRY SCARABS

Curtis Young received a sample of beetles that looked like hairy Japanese beetles (Popillia japonica). Close examination revealed that they were scarab beetles, not Japanese beetles. Curtis identified the beetles as HAIRY FLOWER SCARAB BEETLE (Trichiotinus sp.). The beetles do resemble Japanese beetles with the head, thorax, ventral sides and legs greenish-black in color. The front wings (elytra) are reddish-brown with greenish borders and white bars. Adult hairy flower scarabs feed on the pollen of a variety of flowers and larvae live in decaying wood. Several species can be found in the U.S. and Canada.

WINDSHIELD WIPES

In addition to early fall coloration on burning bushes (Euonymus alatus), TWOSPOTTED SPIDER MITES have been observed causing considerable damage to plants in the Clark County area. Leaves are showing flecking, discoloration, and scorching. Heavy populations could cause defoliation. Periodic hosing of plants with a forceful jet of water knocks the mites from the plant. Horticultural oils and insecticidal soaps are good choices for control as they won't kill populations of predatory mites. Remember, however, sprays must come in contact with the pest so spray under the leaves.

DISEASE DIGEST

CLEMATIS WILTING

Calls are coming into Extension offices about stems in clematis vines wilting. The most devastating problem of clematis is a fungal stem rot and leaf spot caused by the fungus Ascochyta clematidina and commonly called "wilt." This is a disease that is more common on the large-flowered hybrids than on the small-flowered hybrids and species and their cultivars. Symptoms include a sudden stem collapse typically as the flower buds are about to open, and within a few days the stem and leaves turn black. Only one or a few stems in a plant may wilt. The stem discolors and may exhibit lesions below the first pair of wilted leaves. Any part of the plant can be attacked down to and just below the soil level. The usual treatment is to remove the diseased stem below the wilted section, even below soil line. Plants usually recover from buds lower on the stem.

SEPTORIA LEAF SPOT

This disease was reported on the leaves of Cornus alba. The variegated leaves of the shrub were enhanced with tan spots surrounded by purplish halos. Septoria makes a great show, often affecting the entire shrub and premature leaf drop may result. However it does not significantly affect the health of the plant and can usually be considered a cosmetic problem.
Lesions from Septoria start out as brown circular spots. Later they become tan with a purplish halo. The spots are usually angular where they meet veins within the leaf. Small black fruiting bodies can sometimes be found in the lesion. Infestation can intensify as the season progresses.
In an attempt to avoid Septoria, avoid overhead watering or watering in the evening hours. Clean up all fallen leaves to help reduce re-infection. Fungicides can be applied but are usually not recommended to homeowners due to the cosmetic nature of the disease. Fungicides for leaf spotting fungi are listed in OSU Extension Bulletin 614, "Disease Control in the Landscape."

COLLAPSING NEW GUINEA IMPATIENS

Dave Dyke reported that New Guinea impatiens samples he sent into the CWEPPDC a short while ago came back positive for PYTHIUM. The infected plants came from one of two identical beds on either side of a driveway. In one bed, the plants looked great; in the other, all of the white impatiens ('Purity') were completely collapsing and dying throughout the bed while the two darker colored ones ('Ovation Bright Pink' and 'Ovation Cherry Rose') were chlorotic and obviously under stress but not collapsing.
The 'Purity' is apparently much more susceptible to this fungus-like organism than the other varieties in the beds. While the beds appeared to be identical, there appeared to be enough difference in the drainage and/or watering to allow the pythium to run rampant in one bed but not the other.
Pythium (and PHYTOPHTHORA) fungi (actually pseudo fungi) are present in most non-treated soils. They may also be found in washed sand and in certain peats. Pythium and phytophthora are sometimes referred to as water-molds because they produce motile spores that disperse or "swim" in water. Although these pathogens are not good competitors with other soil fungi, they can survive for many years in soil by forming spherical, thick-walled resting spores (oospores). The oospores are relatively common in diseased tissue, and their presence is used in diagnosis.
Pythium root rot often occurs in saturated or poorly draining potting material and sub-optimal temperatures for plant growth. Disease severity may also be increased by excessive nitrogen fertilization.
Plants affected by pythium (or phytophthora) root rot usually are stunted and have a flaccid or wilted appearance. The foliage may appear dull green or yellow as if suffering from nitrogen deficiency. In almost all cases, the roots of diseased plants will show some type of discoloration. The disease often starts as a discoloration of the small lateral roots and root tips. Small, pale brown lesions girdle the root, causing the outer root layer to slough off, leaving behind a thin tendril of inner root (steele). This rat-tail appearance is common for pythium root rot. As the disease advances, roots turn dull brown to black and are water-soaked. Diseased roots tend to break apart easily when washed lightly. Pythium is not just a root rotter, it can also attack the crown. This results in the dieback of the foliage and the eventual death of the plant.
For control methods, including chemical and biological, of this and other root rotting fungi refer to "Root Rot Diseases of Flowering Potted Plants," Extension Plant Pathology, Kansas State University at the website below.

INDUSTRY INSIGHT

SUMMER PRUNING OF WOODY ORNAMENTALS

Good pruning is the art of knowing the natural shape of a plant and maintaining it to maturity. Summer pruning is the time to shape plants by removing selective branches, developing plants into natural shapes, not squares or round figures. If pruned right during the dormant season, many plants only need to be touched up with selective pruning during the summer. Bloom patterns on spring flowering plants can be interrupted or reduced if they are pruned too late in the summer. Late summer pruning also encourages a plant to grow, developing wood that may be damaged by early cold spells.

MONITOR WATER QUALITY AT THIS TIME

Water hardness, pH, and nutrient levels tend to climb as the weather gets hot and dry. Many plant problems come from materials added to the soil from irrigation water. By the time the plants have shown problems, it may be too late for correction. By monitoring water quality, media pH, soluble salts and moisture levels, problems can be corrected before they limit plant growth.
Hand- held meters can be used to accurately measure soluble salts, pH and nutrient levels. Keep records of these values to see trends that might be developing in the nursery. Regardless of the type of system you use, it is important to take readings on a regular basis and record them on a chart. This information can then be used to determine what action is needed to get the best growth.

VISIT BUCKEYEGARDENING.COM

ONLA is excited to announce the redesigned "one stop source" for Ohio gardening enthusiasts! They have been working hard to update their buckeyegardening.com web site since March, and are ready to unveil the new features, new graphics and a new garden store. All the favorites of the former site remain, including the extensive garden articles library, the popular Q & A section, and the searchable member database. New features include a plant hardiness zone map, featured plants, "Plant Knowledge" database and more! Use this site yourself, and point your customers to it, as well.

COMING ATTRACTIONS

WOSU GREEN SCENE

Join WOSU 820 AM host Tom Wiebell this Friday night on Green Scene, from 6:30 to 8:00 p.m. with frequent guest Jim Chatfield of the North Central Extension Region, and Randy Zondag, commercial horticulture Extension agent in Lake County. Tune in or call Green Scene at 614-292-8513 for informed answers and advice for all your horticultural queries and quandaries.

BYGLIVE! IN CINCINNATI

The fourth 2004 BYGLive! Diagnostic Walk-About will be held this coming Monday, July 12, at Spring Grove Cemetery & Arboretum. This monthly hands-on training program focuses on diagnosing plant pest, disease, and physiological problems. Directions to the meeting location are: enter Spring Grove Cemetery & Arboretum through the main entrance off Spring Grove Avenue; straight ahead will be an underpass - drive through the underpass; turn right at the first intersection, and travel approx. 100 yards to the meeting site on your left. For more information, call Joe Boggs at 513-946-8993.

2004 OHIO PLANT HEALTH CARE WORKSHOP: ABIOTIC DISORDERS OF LANDSCAPE PLANTS

This workshop will be held July 14-15, 2004 in Wooster, Ohio. It is the seventh in a series of plant health care workshops co-sponsored by The Ohio State University/OARDC Secrest Arboretum, Ohio State University Extension, and the Extension Nursery, Landscape, and Turf Team (ENLTT). The two-day course on abiotic disorders affecting plants in the landscape will combine proven concepts and practical information to help green industry professionals manage ornamental landscapes and urban forests.
Registration is limited to 40 participants. Deadline for registration is TOMORROW (July 9) . Registration for the two days includes breakfast and lunch both days, dinner on Wednesday, all sessions, materials and handouts for $225.00. For registration or program information, contact Denise Ellsworth, OSU Extension, Summit County, at 330-928-4769 ext 21, e-mail: ellsworth.2@osu.edu, or Diane Dunphy 330-928-4769 ext 27, e-mail: dunphy.2@osu.edu.

SUMMER FIELD DAYS

Willowbend Nursery of Perry is hosting the SUMMER FIELD DAYS in Lake County on Tuesday, August 10th, 2004. The Nursery Growers of Lake County Ohio (NGLCO) website (www.nglcol.com) has registration information as well as a list of exhibitors and area accommodations. Over 170 exhibitors will be housed in air conditioned comfort. Call Karen Hinton at 440-241-7969 for details.

BYGLOSOPHY

"Summer afternoon - summer afternoon; to me those have always been the two most beautiful words in the English language." - Henry James

Where trade names are used, no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears the responsibility of consulting the pesticide label and adhering to those directions.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department o f Agriculture, Keith L. Smith, Director, Ohio State University Extension.
All Ohio State University Extension educational programs are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability, or Vietnam-era veteran status.

Bygl index

Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, Dave Goerig, Dan Herms, Tim Malinich, Jane Martin, Pam Sherratt, Amy Stone, and Curtis Young
July 08, 2004
This is the Fourteenth 2004 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension agents, specialists and other contributors in Ohio. BYGL is also made available on the Internet from the Ohio State University Horticulture and Crop Science (HCS) in Virtual Perspective website (http://bygl.osu.edu). Additional fact sheet information on any of these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu). BYGL is a service of OSU Extension and is aided by major support from the Ohio Nursery and Landscape Association (ONLA), with additional funding from the Ohio Chapter of the International Society of Arboriculture (ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT). Participants in the July 06, 2004 conference included: Pam Bennett (Clark); Barb Bloetscher (Entomology and C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/South District); Jim Chatfield (North District/ Horticulture and Crop Science Department-HCS); Dave Dyke (Hamilton); Tim Malanich (Cuyahoga); Jane Martin (Franklin) Joe Rimelspach (Plant Pathology); Curtis Young (Allen); Nancy Taylor (C. Wayne Ellet Plant and Pest Diagnostic Clinic (CWEPPDC)); and Randy Zondag (Lake). Additional factsheet information on any of these articles may be found through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
WEATHER WATCH
Joe Boggs noted that the Cincinnati area is relatively dry; however, a recent rain event in parts of the area started to green things up. He reported that the recorded rainfall for the month of June is 0.34", just slightly down from normal; they are at +.21" for the year to date. Jane Martin reported that Columbus is all dried up! Their last significant rainfall was on June 13th with .55" of rain. They have had localized showers since. June rainfall was 5.34", which was +1.26. The year to date total for the Columbus area is 25.89", which puts them at +6.38 for the year. Pam Bennett reported similar weather conditions in the Clark County area. She also reminded BYGLers that precipitation amounts are only relative to the site where the data was obtained. For instance, the OARDC Western Branch site outside of the city reported 3.5" of rain for June and +4.45 for the year. Another weather man within the city recorded 0.00" for June and +11.79 for the year. The additional amount was a result of 8.17" of rain in May.
HORT SHORTS
CORNELL'S VEG MD. Now that the vegetable gardening season is in full swing, insect pests and diseases are also making their appearance and confounding gardeners. Of course, the first step in managing a pest is to identify it, and to that end, the Cornell University Department of Plant Pathology has developed a web site known as "Vegetable MD Online" that focuses on vegetable diseases. This site is searchable by crop or by photos and also links you to Cornell fact sheets on the various vegetable diseases. The photos assist in arriving at a diagnosis.
BUG BYTES
CONEFLOWERS DISTORTED Purple coneflowers are an essential component of most perennial gardens. However, the flowers can be distorted by an eriophyid mite, reducing their value for use in indoor arrangements. These tiny, carrot-shaped mites live inside the opening flower buds and suck nutrients from the base of the flowers. As a result, both the disk flowers (the dark center) and the ray flowers (elongated purple petals) can become stunted, misshapen, or are absent entirely. The mites overwinter in the plant's roots and become active again in the spring. There are various recommendations on controlling this pest. One is to rogue the planting, not replanting in the same area with coneflower, at least for several seasons. Infested flowers should be cut and removed from the garden; between cuts, dip pruners in an alcohol-based solution to clean them. Little can be done to treat this mite once the problem is noticed in a season, however, preventive systemic insecticides can help to reduce the incidence in following seasons. Treat in early spring as new growth begins using a systemic insecticide labeled for flowers.
CICADA MANIA CONTINUES Just when we were beginning to think we would loose our hearing because of the on-going droning buzz of the periodical cicada, they died off along with their mating calls. However, now we are trading one buzzer for another. The ANNUAL or DOG-DAY CICADAS (Tibicen spp.) have emerged and started up their choruses of mating calls. Fortunately, there are fewer (LOTS FEWER) of these love-sick crooners singing their songs than were present in the areas with periodic cicadas. Like their relatives the periodical cicada, annual cicadas also develop underground where the nymphs suck sap from plant roots. It may take two to three years for them to complete their development, but there are some adults emerging every year due to overlapping generations. Full grown nymphs emerge from the soil, crawl up a near by vertical surface, and molt to the adult stage. Emerging adults pull themselves out of the nymphal exoskeleton, expand their wings, harden their bodies, and fly off to find a mate. Male cicadas attract female cicadas with their songs. Once mated, the females lay their eggs under the bark of twigs and stems of trees and shrubs. Newly hatched nymphs fall to the ground and burrow into the soil to find a food source and begin development toward the adult stage. Cicada feeding causes little if any injury to the host plants. Some damage may occur from egg laying (oviposition). Because they cause little injury, controls are not recommended.
FIRE ANTS IN OHIO?? The CWEPPDC and Hamilton County Extension office have received several calls from alarmed citizens who claimed to have been bitten by fire ants. Upon questioning, they describe the ants as 1/8 - 1/4" long and red with black abdomens. The soil mounds in the yard can be several inches to 30" high and up to 13' wide. Several interconnected smaller mounds often surround the main mound. Armed with this description and the fact that fire ants are not established in Ohio, specialists have been able to advise that these are Alleghany mound ants (Formica exsectoides Forel), not fire ants. Two fire ants can be found in the United states, the Southern fire ant (Solenopsis xyloni McCook) and red imported fire ant (Solenopsis invicta Buren). While the Southern fire ant ranges from California to South Carolina to Florida, the latter is found mostly in the southeastern states, but can be found as far north as Virginia. Most importantly, these ants will silently sneak en masse upon their prey and suddenly sting with an extruded "stinger" at the tip of its abdomen. These excruciating stings can cause welts and scars. Allegheny mound ants tend to individually bite or pinch an object close to its nest or in the way, causing a sharp temporary pain. Since the ants are primarily beneficial in that they eat soft-bodied insects, it is usually recommended to leave the ants alone, but avoid planting shrubs or flowers near the home and sidewalks, patios, decks, etc. that attract insects. Few insecticides are labeled for outdoor applications to ant mounds, as people, pets and birds can be exposed to insecticides applied on top of the ground.
HAIRY SCARABS Curtis Young received a sample of beetles that looked like hairy Japanese beetles (Popillia japonica). Close examination revealed that they were scarab beetles, not Japanese beetles. Curtis identified the beetles as HAIRY FLOWER SCARAB BEETLE (Trichiotinus sp.). The beetles do resemble Japanese beetles with the head, thorax, ventral sides and legs greenish-black in color. The front wings (elytra) are reddish-brown with greenish borders and white bars. Adult hairy flower scarabs feed on the pollen of a variety of flowers and larvae live in decaying wood. Several species can be found in the U.S. and Canada.
WINDSHIELD WIPES In addition to early fall coloration on burning bushes (Euonymus alatus), TWOSPOTTED SPIDER MITES have been observed causing considerable damage to plants in the Clark County area. Leaves are showing flecking, discoloration, and scorching. Heavy populations could cause defoliation. Periodic hosing of plants with a forceful jet of water knocks the mites from the plant. Horticultural oils and insecticidal soaps are good choices for control as they won't kill populations of predatory mites. Remember, however, sprays must come in contact with the pest so spray under the leaves.
DISEASE DIGEST
CLEMATIS WILTING Calls are coming into Extension offices about stems in clematis vines wilting. The most devastating problem of clematis is a fungal stem rot and leaf spot caused by the fungus Ascochyta clematidina and commonly called "wilt." This is a disease that is more common on the large-flowered hybrids than on the small-flowered hybrids and species and their cultivars. Symptoms include a sudden stem collapse typically as the flower buds are about to open, and within a few days the stem and leaves turn black. Only one or a few stems in a plant may wilt. The stem discolors and may exhibit lesions below the first pair of wilted leaves. Any part of the plant can be attacked down to and just below the soil level. The usual treatment is to remove the diseased stem below the wilted section, even below soil line. Plants usually recover from buds lower on the stem.
SEPTORIA LEAF SPOT This disease was reported on the leaves of Cornus alba. The variegated leaves of the shrub were enhanced with tan spots surrounded by purplish halos. Septoria makes a great show, often affecting the entire shrub and premature leaf drop may result. However it does not significantly affect the health of the plant and can usually be considered a cosmetic problem. Lesions from Septoria start out as brown circular spots. Later they become tan with a purplish halo. The spots are usually angular where they meet veins within the leaf. Small black fruiting bodies can sometimes be found in the lesion. Infestation can intensify as the season progresses. In an attempt to avoid Septoria, avoid overhead watering or watering in the evening hours. Clean up all fallen leaves to help reduce re-infection. Fungicides can be applied but are usually not recommended to homeowners due to the cosmetic nature of the disease. Fungicides for leaf spotting fungi are listed in OSU Extension Bulletin 614, "Disease Control in the Landscape."
COLLAPSING NEW GUINEA IMPATIENS Dave Dyke reported that New Guinea impatiens samples he sent into the CWEPPDC a short while ago came back positive for PYTHIUM. The infected plants came from one of two identical beds on either side of a driveway. In one bed, the plants looked great; in the other, all of the white impatiens ('Purity') were completely collapsing and dying throughout the bed while the two darker colored ones ('Ovation Bright Pink' and 'Ovation Cherry Rose') were chlorotic and obviously under stress but not collapsing. The 'Purity' is apparently much more susceptible to this fungus-like organism than the other varieties in the beds. While the beds appeared to be identical, there appeared to be enough difference in the drainage and/or watering to allow the pythium to run rampant in one bed but not the other. Pythium (and PHYTOPHTHORA) fungi (actually pseudo fungi) are present in most non-treated soils. They may also be found in washed sand and in certain peats. Pythium and phytophthora are sometimes referred to as water-molds because they produce motile spores that disperse or "swim" in water. Although these pathogens are not good competitors with other soil fungi, they can survive for many years in soil by forming spherical, thick-walled resting spores (oospores). The oospores are relatively common in diseased tissue, and their presence is used in diagnosis. Pythium root rot often occurs in saturated or poorly draining potting material and sub-optimal temperatures for plant growth. Disease severity may also be increased by excessive nitrogen fertilization. Plants affected by pythium (or phytophthora) root rot usually are stunted and have a flaccid or wilted appearance. The foliage may appear dull green or yellow as if suffering from nitrogen deficiency. In almost all cases, the roots of diseased plants will show some type of discoloration. The disease often starts as a discoloration of the small lateral roots and root tips. Small, pale brown lesions girdle the root, causing the outer root layer to slough off, leaving behind a thin tendril of inner root (steele). This rat-tail appearance is common for pythium root rot. As the disease advances, roots turn dull brown to black and are water-soaked. Diseased roots tend to break apart easily when washed lightly. Pythium is not just a root rotter, it can also attack the crown. This results in the dieback of the foliage and the eventual death of the plant. For control methods, including chemical and biological, of this and other root rotting fungi refer to "Root Rot Diseases of Flowering Potted Plants," Extension Plant Pathology, Kansas State University at the website below.
INDUSTRY INSIGHT
SUMMER PRUNING OF WOODY ORNAMENTALS Good pruning is the art of knowing the natural shape of a plant and maintaining it to maturity. Summer pruning is the time to shape plants by removing selective branches, developing plants into natural shapes, not squares or round figures. If pruned right during the dormant season, many plants only need to be touched up with selective pruning during the summer. Bloom patterns on spring flowering plants can be interrupted or reduced if they are pruned too late in the summer. Late summer pruning also encourages a plant to grow, developing wood that may be damaged by early cold spells.
MONITOR WATER QUALITY AT THIS TIME Water hardness, pH, and nutrient levels tend to climb as the weather gets hot and dry. Many plant problems come from materials added to the soil from irrigation water. By the time the plants have shown problems, it may be too late for correction. By monitoring water quality, media pH, soluble salts and moisture levels, problems can be corrected before they limit plant growth. Hand- held meters can be used to accurately measure soluble salts, pH and nutrient levels. Keep records of these values to see trends that might be developing in the nursery. Regardless of the type of system you use, it is important to take readings on a regular basis and record them on a chart. This information can then be used to determine what action is needed to get the best growth.
VISIT BUCKEYEGARDENING.COM ONLA is excited to announce the redesigned "one stop source" for Ohio gardening enthusiasts! They have been working hard to update their buckeyegardening.com web site since March, and are ready to unveil the new features, new graphics and a new garden store. All the favorites of the former site remain, including the extensive garden articles library, the popular Q & A section, and the searchable member database. New features include a plant hardiness zone map, featured plants, "Plant Knowledge" database and more! Use this site yourself, and point your customers to it, as well.
COMING ATTRACTIONS
WOSU GREEN SCENE Join WOSU 820 AM host Tom Wiebell this Friday night on Green Scene, from 6:30 to 8:00 p.m. with frequent guest Jim Chatfield of the North Central Extension Region, and Randy Zondag, commercial horticulture Extension agent in Lake County. Tune in or call Green Scene at 614-292-8513 for informed answers and advice for all your horticultural queries and quandaries.
BYGLIVE! IN CINCINNATI The fourth 2004 BYGLive! Diagnostic Walk-About will be held this coming Monday, July 12, at Spring Grove Cemetery & Arboretum. This monthly hands-on training program focuses on diagnosing plant pest, disease, and physiological problems. Directions to the meeting location are: enter Spring Grove Cemetery & Arboretum through the main entrance off Spring Grove Avenue; straight ahead will be an underpass - drive through the underpass; turn right at the first intersection, and travel approx. 100 yards to the meeting site on your left. For more information, call Joe Boggs at 513-946-8993.
2004 OHIO PLANT HEALTH CARE WORKSHOP: ABIOTIC DISORDERS OF LANDSCAPE PLANTS This workshop will be held July 14-15, 2004 in Wooster, Ohio. It is the seventh in a series of plant health care workshops co-sponsored by The Ohio State University/OARDC Secrest Arboretum, Ohio State University Extension, and the Extension Nursery, Landscape, and Turf Team (ENLTT). The two-day course on abiotic disorders affecting plants in the landscape will combine proven concepts and practical information to help green industry professionals manage ornamental landscapes and urban forests. Registration is limited to 40 participants. Deadline for registration is TOMORROW (July 9) . Registration for the two days includes breakfast and lunch both days, dinner on Wednesday, all sessions, materials and handouts for $225.00. For registration or program information, contact Denise Ellsworth, OSU Extension, Summit County, at 330-928-4769 ext 21, e-mail: ellsworth.2@osu.edu, or Diane Dunphy 330-928-4769 ext 27, e-mail: dunphy.2@osu.edu.
SUMMER FIELD DAYS Willowbend Nursery of Perry is hosting the SUMMER FIELD DAYS in Lake County on Tuesday, August 10th, 2004. The Nursery Growers of Lake County Ohio (NGLCO) website (www.nglcol.com) has registration information as well as a list of exhibitors and area accommodations. Over 170 exhibitors will be housed in air conditioned comfort. Call Karen Hinton at 440-241-7969 for details.
BYGLOSOPHY
"Summer afternoon - summer afternoon; to me those have always been the two most beautiful words in the English language." - Henry James