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In The Backyard

Horticulture columns and tips done on a timely basis

July 23, 2007

Fair Time

It doesn't seem possible, but the calendar assures me that the Logan County Fair actually starts next week on Tuesday, July 31. The Illinois State Fair will start about a week later, but 4-H

involvement there will actually start about 4 days in advance of the official opening date. In case of an emergency call the regular office number at 732-8289. Please be patient, as the office will not accessible during the fair, except through the fairgrounds. The fair is a true community event so come on out and support your favorite activity at your community fair. There are countless volunteer hours put into a successful fair, and your support is what keeps the whole thing going.

Posted by John Fulton at 11:57 AM | Permalink |

July 23, 2007

Cicada Killer Wasp

The cicada killer wasps have returned! They are actually considered beneficial insects because they control cicadas. This wasp gets its common name due to the fact that it hunts and supplies its nest chambers with a cicada, which becomes a food source for the young cicada killer. Other food sources could include katydids and grasshoppers. We are getting cicada killers now because of the beginning emergence of the dogday cicada. Cicada killers are a nuisance pest, especially when nesting in large numbers in a play area or near the house. People get concerned because the cicada killers resemble giant yellowjackets.

Cicada killers are about 2 inches long and black to red, with yellow banded markings on the abdomen. The head and transparent wings are reddish brown. They are not dangerous, but they are intimidating. Cicada killers are solitary wasps, with the female digging a 6- to 10-inch burrow (1/2 inch in diameter) in the ground. A pile of soil typically surrounds the entrance. The female locates and stings a large insect such as a cicada or katydid and then brings it back to the burrow. She places the insect into a chamber and lays an egg on it; sometimes she puts two in a burrow but lays an egg on only one. She then covers the burrow, digs another, and repeats the process. The egg hatches into a grublike, legless larva that consumes the paralyzed insect. Full-grown larvae overwinter in the burrow, pupate in the spring, and emerge as an adult during the summer, usually in July and August.

Male cicada killers establish aerial territories and patrol for intruders. A male cicada killer drives off other males that enter his territory and attempts to mate with females. Anyone else walking into the territory is typically confronted by a very large wasp, which hovers in front of the face and zips to the side and back. However, after determining that the "intruder" is not a rival, the wasp ignores the individual.

Cicada killers are unlikely to sting a person. Wasp and bee stingers are modified egg-laying devices (ovipositors), so males are not able to sting. Females may sting if crushed, either by being stepped on with bare feet or grabbed with bare hands.

Cicada killers are more common in areas with bare soil, so mulching, planting ground covers, or putting down sod can reduce problems. Applying permethrin or Sevin (some suggest the Sevin dust gives better control) to the burrowed area should kill females in high traffic areas. Once females are gone, males leave. In home yards, sandboxes can be covered with a tarp when not in use, as this deters the wasps (and also keep cats out). Sand below swings, jungle gyms, or other playground equipment is a popular site for the cicada killer. Raking the sand may discourage the wasps, or you could use mulch instead of the sand.

Posted by John Fulton at 11:56 AM | Permalink |

July 23, 2007

Weekly Rainfall

Logan County Extension Office

Week ending

Rainfall in inches

Week ending

Rainfall in inches

3/11

.14

6/10

0.0

3/18

.02

6/17

0.0

3/25

1.24

6/24

3.12

4/1

.34

7/1

1.10

4/8

.12

7/8

.92

4/15

.80

7/15

Missed recording/added in 7/22

4/22

0.0

7/22

2.28

4/29

1.32

5/6

.94

5/13

0.0

5/20

.6

5/27

.56

6/3

1.4

Posted by John Fulton at 11:53 AM | Permalink |

July 9, 2007

Tomato Diseases

Tomato Diseases

It seems like the tomato is the one plant that just about everybody tries to grow. Some people grow large amounts, while others plant one or two in containers. At any rate, the calls and samples have started coming in to the office already. Most of the samples have spots, brown leaves, and dropping leaves, or all of the above. Several diseases hit tomatoes, but two of the more common ones are early blight and seporia leaf spot.

Early blight, also know as Alternaria leaf spot, can affect plants at any stage of development. All above ground parts are susceptible. The most characteristic symptom of early blight are spreading spots, ¼ to ½ inch in diameter that form on lower or older leaves. These spots have dark edges and they are usually brown to black in the center. These spots frequently merge forming irregular blotches. Concentric rings often form creating a 'target' or 'bulls-eye' effect. Affected leaves develop yellow areas around the lesions. Spotted leaves soon turn yellow, whither and drop off. The fungus may cause lesions on the fruit around the stem end and shoulder. The lesion is usually dark brown to black, up to an inch in diameter, and with distinct concentric rings.

Septoria leaf spot can also affect plants at any stage of development. Numerous small, water-soaked spots first appear on the lower leaves. These spots soon become circular to angular with dark margins and grayish centers often bearing one or more tiny black bodies called pycnidia which are spore-bearing structures. Individual lesions are seldom more than ? inch in diameter and are usually quite numerous on an infected leaf. Heavily diseased leaves turn yellow, wither and drop off in large numbers, starting at the base of the plant. Defoliation can be severe during prolonged periods of warm, wet weather.

As for what to do, here is the checklist: First, keep ripe fruits picked off the plants. Second, don't work around tomatoes when they are wet. Next, you can try and improve air circulation, but if your tomatoes are severely affected you won't want to lose any more leaves. And the final step for this year is to try a fungicide. Mancozeb is probably the recommended one, but it is very hard to find. The other option is use maneb or Daconil, which are much easier to find but probably won't give you great control. The final step for future years is to practice at least a three year rotation, with good sanitation in the garden.

Another disease that is actually an environmental problem is blossom end rot. There have been several samples of this brought to the office this year. This is where the bottom of the tomato (the blossom end) becomes dark and leathery. The condition is actually caused by a calcium imbalance in the plant due to uneven moisture. The best solution is mulching the area around the tomato with 2-4 inches of mulch. Addition of calcium may or may not help the problem, but almost certainly won't this late in the game.

That being said, enjoy those tomatoes!

Posted by John Fulton at 4:42 PM | Permalink |

July 9, 2007

Weekly Rainfall

Logan County Extension Office

Week ending

Rainfall in inches

Week ending

Rainfall in inches

3/11

.14

6/10

0.0

3/18

.02

6/17

0.0

3/25

1.24

6/24

3.12

4/1

.34

7/1

1.10

4/8

.12

7/8

.92

4/15

.80

4/22

0.0

4/29

1.32

5/6

.94

5/13

0.0

5/20

.6

5/27

.56

6/3

1.4

Posted by John Fulton at 4:35 PM | Permalink |

July 6, 2007

Yellow Grass

There seem to be many yellow patches of grass showing up in area lawns. Large amounts of rain could have pushed nitrogen below the level where grass roots can reach it, or it can lead to denitrification, where the bacteria in the soil break down nitrate forms of nitrogen for the oxygen they contain. Any root damage also reduces the amount of nitrogen and other elements that can be taken up into plants. Grubs of any sort, including Japanese beetle larvae, feed on plant roots. Add to this the fact that many of the yellow spots are in the area of tree roots. Trees compete for the same moisture and nutrients as grass areas, and trees are more efficient at getting these nutrients.

The long and short of it is yellow grass areas are probably going to be with us for most of the season. Adding additional nitrogen now is not recommended unless you are on a frequent watering schedule. Even then you probably won't green it up any time soon. The yellow is not that efficient a pigment for making food, so those areas will be a little less healthy than others. Try to mow at recommended heights of two to two and a half inches tall, fertilize in early September, and water at least a quarter of an inch per month if things stay dry for a month.

Posted by John Fulton at 9:01 AM | Permalink |

July 6, 2007

Pruning Evergreens

This is the time of year to wrap up pruning chores on evergreens. This includes both needle-type and broadleaf evergreens. If you're wondering what a broadleaf evergreen is, that includes holly, rhododendron, and azalea. The logic behind pruning your yews at this time is to allow sufficient time for regrowth to become hardened off before winter, and to keep new growth from becoming too rank before the winter months.

Pruning evergreens is part art and part science, but mostly art. A few simple rules to follow make the job results much more pleasing. Upright growing evergreens, such as pines and spruces, should not have the main leader cut off. This will destroy the natural shape, and will make the resulting growth more susceptible to breaking off. If individual branches are being cut off, they should be cut back to a bud. This will allow the bud to become the new main branch. You can also control growth direction of branches in this way. If you are growing trees for cut Christmas trees, all bets are off, as you are only dealing with trees through the first seven years of their life or so.

Make sure you use the proper equipment. Individual pruning cuts are best done with bypass loppers or pruning shears. These make clean cuts without much damage to the remaining wood. The old anvil type shears and loppers cut to a point, then crush the remaining wood. For yews, junipers, and arborvitae that are trained to a certain size of shape, you will want to use hedge shears (electric or manual) that are sharp and properly tightened. Most of these types of shears can cut up to about a quarter of an inch in size.

When pruning evergreens, remember the dead zone. This is the area toward the center of the plant that doesn't receive much light. It also has few needles or active buds. Cutting into the dead zone will cause many years (or forever) of little green growth. Also remember to prune so that the base of plants is wider that the top. This allows sunlight to hit the bottom area as well, and keeps the bottom from dieing up.

Posted by John Fulton at 9:00 AM | Permalink |

July 6, 2007

Japanese Beetle Update

The numbers of adults have been impressive in some cases. Trees, shrubs, vegetable plants, and fruit plants and trees have all been affected. Of course there are some plants that are favored feeding sites. These would include Japanese maple, Norway maple, Horsechestnut, Hollyhock, Flowering crabapple, Apple, Cherry, Peach, Rose, Mountain ash, Linden, and Grape. There are other plants that are seldom attacked such as Red maple, Silver maple, Boxwood, Flowering dogwood, Euonymus, Ash, Oak, and Lilac. Of course you need to take this list with a grain of salt since I have sprayed large numbers of beetles on the seldom attacked plants this weekend.

My rule of thumb is protect fruits, vegetables, valuable ornamentals, and new transplants. Most are spraying Orthene, Sevin, permethrin, or bifenthrin. The frequency is what gets us sometimes with sprays needed at least every week in most cases. To dispel a common myth, once you have the beetles you will always have them. They do not occur on an infrequent basis like periodical cicadas, nor it is "just a year to have them." They have expanded their range, and you are now in it.

Posted by John Fulton at 8:56 AM | Permalink |