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In The Backyard

Horticulture columns and tips done on a timely basis

September 24, 2010

Broadleaf Weed Control in the Fall

Fall is a great time to try and control problem perennial weeds in the lawn. The weeds are in the process of storing energy in the roots and crowns so they can come out again next year. This translocation of food also provides a great way to move pesticides in the plants.

Problem perennial weeds would include things like ground ivy, violets, speedwell, and others. Of course, a treatment will also get dandelions and plantain. For most problem weeds, a combination of 2,4-D, MCPP, and dicamba will do the trick. There are many pre-mixed herbicides with these ingredients. Many are adding triclopyr to the mixture as well, and mainly for violet control. Try to pick a day when winds are slight, and when temperatures aren't predicted to be above 85 degrees for a while. Normally the late September time doesn't present the temperature problem, but this year seems to be an exception. The dicamba can vapor drift after application. Many gardens are about done, but flowers, shrubs, and trees are also translocation food. You need to be cautious whenever applying chemicals. Read the label and follow all recommendations.

Posted by John Fulton at 4:11 PM | Permalink |

September 24, 2010

Brown Needles on Pine Trees

Brown needles happen on pine trees, and other evergreens, all the time. Of course, some times are more striking than others. Is this a bad thing? It all depends. To begin with, evergreens only keep one to four years of green growth toward the tips of the branches. The number of years is dependent on weather conditions, the health of the tree, and the species. Needles toward the trunk of the tree turn brown each year and drop off.

If weather conditions are just right, the needles all turn brown at once. If there aren't any heavy rains or winds to help knock needles off gradually, the brown needles are quite showy. They will drop off, and the appearance of the tree will return to normal. The only exception is the green needles are now further away from the trunk.

Every evergreen has a "dead zone" for these reasons. A dead zone has no green needles or buds in it. You end up with a dead tree prune if you prune into the dead zone. This can also make for unsightly trees when the branches become very long and begin to droop. This exposes the dead zone, and makes the trees appear to be sparse.

Stressful years make the brown needle phenomenon more pronounced. I would classify this year as highly stressful, with the combination of heavy rains and heat. This type of weather is worse on evergreens than most plants, because most evergreens planted over the last 50 years really aren't very well suited for Central Illinois. White pines are really a northern understory tree. That means they are better suited for Wisconsin and north, and they are in a mixed timber with other trees that shade them. Spruces and firs are mostly western, high-altitude trees. Red pines are native to the Northeast and to Northern Illinois, but they have some disease problems. Austrian pines have many disease problems and don't usually see 40 years old. The white (concolor) fir is another western species, but has held up about as well as any evergreen in our area.

As for what to do, just take good care of the trees. Fertilize the lawn area around the trees at the lawn rate to supply a pound each of nitrogen, phosphorus, and potassium per 1000 square feet in the fall and the spring. The trees will get the fertilizer they need before the grass can get it. The drying winds of winter may also take their toll. Use a wind block, or treat with an antidessicant such Wilt Pruf, to keep needles from drying in the winter.

Posted by John Fulton at 4:09 PM | Permalink |

September 20, 2010

Think Safety on the Road during the Fall Harvest

The fall harvest and farming season has begun in earnest. Remember to use caution around the slow moving equipment. A speed of 20 miles per hour will be about the highest you will see on roadways from tractors. Farm equipment is also large and heavy. Be patient and exercise caution when farm equipment is on the road. We all need to share the roadway, so let's do it safely.

Posted by John Fulton at 3:13 PM | Permalink |

September 20, 2010

Dead Grass Spots

There are many dead spots in lawns, and there will be more in a short time. Many spots have been present since mid-summer, and were due to fungi killing the grass. As a simple review, it is not recommended to treat a fungus in home lawns due to the cost, frequency, and potential allergic reaction of people and pets. In some cases, the extremely wet weather, followed by hot, dry conditions actually killed portions of lawns. The third possible problem is grub damage. There have been reports of high numbers of grubs reported in spots within the yard, and along edges of driveways and sidewalks.

As for what to do, the grub problem would need to be treated. Japanese beetle grubs should have all hatched out by now, so controls would be effective. Traditional grub treatments and carbaryl (Sevin) are effective on Japanese beetle grubs. The carbaryl is not effective on other types of grubs. After grub treatment, and to deal with the other causes of dead grass spots, get new seed down quickly. We are actually beyond the date to put down new seed, but the odds for seeding success are generally better in the fall.

Posted by John Fulton at 3:12 PM | Permalink |

September 20, 2010

Holes in Trees

Many people are reporting holes in trees. These holes are round and in a pattern either around or up and down on tree trunks. They are also usually found in a tree that has high sap flows such as maples, gums, or evergreens. These holes are caused by yellow bellied sapsuckers. About the time we notice the holes, the birds are gone. They migrate and only bless us with their presence about two months in the spring (around May) and again in the fall (around September). Sapsuckers are migrating through the area now, and they will remain with us until their instincts tell them to head further south. These holes can cause injury to the tree by allowing a place for insects and disease to get in, and death if they completely girdle trees. Control is very difficult, and consists of trying to scare the birds with pie pans, whirlybirds, rubber snakes, or other items that make sound or sight.

If damage in an area of the tree trunk is severe, you can wrap burlap around that portion to protect it. The sticky type products, such as Tanglefoot would also have some effect, but might cause problems for some of the non-sapsuckers in the area.

Several others caused for holes do exist. Other than sapsuckers, the main causes lately have included borers and carpenter ants. Carpenter ants are the large, black ants that are very noticeable. They get their name from where they lay their eggs – meaning the female chews holes in wood to make a nesting galley. The damage from the carpenter ant is not of the same degree as termites. Termites digest the wood fiber and structurally weaken it, while the carpenter ants make holes in the wood and don't weaken it.

The bad news is that carpenter ants like to nest in dead wood. If you have ant activity in a tree, odds are that there is some dead wood in the tree. You can help the situation with secondary insects, such as carpenter ants, by painting exposed wood with exterior latex paint or spraying with an insecticide that has some residual. Current choices would be bifenthrin or permethrin.

Posted by John Fulton at 3:05 PM | Permalink |

September 9, 2010

Fall Reminders

Fall seems to be bearing down on us. The warm days and cooler nights definitely bring to mind the seasons are changing. This week's offering will cover many short topics with reminders, alerts, and the to-do list.

Lawn work can be in high gear. Reseeding or overseeding should be done this week. Use about two pounds of seed per 1000 square feet of lawn for overseeding and twice that for worked up areas. A blend of grasses with Kentucky bluegrass, perennial ryegrass, and red or chewings fescue is most common. The idea is to get the grass established before freezing weather, and remember bluegrass can take up to a month to germinate. The intrusive operations, such as dethatching and core aeration are also best done at this time.

The last half of September is an ideal time to apply broadleaf weed control for perennial weeds. This will affect young grass, so don't apply any chemicals at this time if you put down new seed. The rule of thumb is you need to mow new grass at least two times before applying broadleaf products. Combinations of 2,4-D, MCPP, and dicamba bought as a premix are most common and broad spectrum. Remember you can get vapor drift with dicamba if temperatures are over 85 degrees or so. It is best to wait later in the month with dicamba to preserve the neighbor's tomatoes.

We are rapidly approaching the time to plant tulips, daffodils, and other spring-flowering bulbs. They should be fall planted before a killing frost. That date is usually about the second week in October in our area. Plant larger bulbs six to eight inches deep, and smaller ones three to four inches deep. Mix into the soil five tablespoons of 10-10-10 fertilizer and two cups of bone meal per 10 square feet of bed area. It is also time to dig summer flowering bulbs such as canna and dahlia as their foliage turns yellow. Store them on layers of sawdust or peat moss in a cool, dry place.

The nuisance pest population is really building up. There are the intrusive pests such as crickets, millipedes, and Asian ladybugs, and the outdoor pests such as syrphid flies, hornets, and mosquitoes. For the ones invading the home, try the foundation sprays of bifenthrin or permethrin to help reduce the number in the home. For the outdoor pests, use repellents containing DEET for mosquitoes. Proper sanitation will help with hornets, and the syrpid flies (which many call sweat bees) are actually beneficial insects eating scale crawlers and aphids.

Harvest pumpkins before the stems turn brown. The heat has really moved things along this year. You should leave at least two inched of stem attached to the pumpkin, and using pruning shears is a great way to harvest pumpkins or squash. Here are some additional tips for pumpkins, even though we are in early September:

  • Choose a pumpkin with a stem and never carry it by the stem. Pumpkins without a stem will not last long.
  • Select a pumpkin with a flat bottom, so it will stand upright
  • Avoid pumpkins with holes, cuts or soft spots. These areas will rot.
  • Light colored pumpkins are easier to carve because the skin is not as hard as darker orange colored ones, but they will not keep as well.
  • Wash the pumpkin with warm water and let it dry before carving. Use of a small amount of dishwashing soap in the warm water may help extend the life of the pumpkin.
  • To make the pumpkin last longer, keep it in a cool place until ready to carve. After carving, coat the cuts with petroleum jelly.
  • Carving should only be done three days ahead of Halloween. After cutting, the pumpkin will deteriorate rapidly.

Posted by John Fulton at 2:27 PM | Permalink |