Hort Update for the week of 10/9/2009
1. Late fall fertilization is important for cool season turfgrasses (Kentucky bluegrass and tall fescue). It promotes root and rhizome growth and carbohydrate storage within the plant. Use a fertilizer where at least 50% of the nitrogen is from a slow release source to avoid promoting growth going into winter. Apply fertilizers at the time of the last mowing in late October or early November at a rate of 1 to 1.5 pounds of nitrogen per 1000 square feet.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
Kentucky Bluegrass Lawn Calendar, University of Nebraska- Lincoln Extension
Tall Fescue Lawn Calendar, University of Nebraska- Lincoln Extension
2. Fall lawn irrigation, in the absence of rainfall, is important for maintaining a moist soil to support root and rhizome growth during fall and to help turfgrass withstand winter injuries. Turfgrass soils should remain moist, not saturated, well into fall. Irrigation systems must also be protected from freeze damage by draining them. Information on proper drainage procedures for home lawn irrigation systems with back flow preventers can be found on page 23 of the Integrated Turfgrass Management for the Northern Great Plains E.C.97-1557. A copy of this Extension circular is available at most UNL Extension offices.
3. Rake or mow tree leaves on a regular basis to avoid the build-up of leaves on turfgrass for longer than 3 to 4 days. If leaving leaves on turfgrass after mowing, mow when leaves are dry. Pulverize leaves by using a mulching mower or making two to three passes. After mowing, the pulverized leaves should not cover the turf but filter into turfgrass so green grass blades are exposed.
Mulch Them/Mow Them in Place
4. Avoid traffic on frozen turf or grass crowns will be damaged leaving foot prints or pathways that are very slow to recover during spring. Walking on frozen dormant turfgrass is most harmful.
5. Fall tree fertilization, if needed for trees growing away from fertilized lawns such as in a windbreak, should be done after trees go dormant later in fall. As a rule, trees growing in fertilized lawns should not be fertilized. Trees only require ½ pound of nitrogen per growing season. This amount is provided from lawn fertilization. Additional fertilizer is harmful to landscape trees.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
6. Fall tree irrigation is important to promote root growth and reduce winter dessication injury. Continue irrigation, in the absence of rainfall, until close to soil freeze. Water when air temperatures are above 40 degrees Fahrenheit and early enough in the day for water to soak into the ground to avoid water freezing on the surface at night. Moisten the soil eight inches deep at the drip line of the tree. Check soil before irrigating to avoid a saturated soil. Roots will not grow without oxygen.
7. Pruning of deciduous trees and shrubs is best done after the plants are dormant. Evergreens like Japanese Yew, Junipers and Arborvitae can be pruned when deciduous plants are pruned, but early spring is ideal. Prune spruce and fir from April to August. Prune pines just as new growth has occurred, sometime from mid-June to mid-July.
Pruning Mature Trees, International Society of Arboriculture
Pruning Evergreens, University of Nebraska- Lincoln Extension
8. Protection from wildlife. Barriers of hardware cloth placed around young trees and shrubs is the best means of protection from rabbit and vole damage. Make sure the barriers extend well above the usual snow line. Various taste repellants, such as Thiram or Millers Hot Sauce, can be effective in reducing deer and rabbit damage as long as animals have other food sources to turn to. Scent repellants, such as bags of human hair or bar soaps on a rope, have been shown to be effective in some situations.
Deer Damage Management, eXtension- National Cooperative Extension System
Vole Damage Management, eXtension- National Cooperative Extension System
Rabbit Damage Management, eXtension- National Cooperative Extension System
9. Iron Chlorosis causes leaves of trees and shrubs to be light green to yellow with darker green leaf veins. It is often due to a high or alkaline pH soil which reduces availability of iron or manganese to some plants. It is most common in pin oak and silver maple. Reports of an increase in chlorosis in plants other than pin oak and silver maple are being made. These plants include spirea, roses, red maple, and others. For trees, apply iron via soil treatment or trunk injection. For smaller plants, promote a healthy rooting environment and soil apply iron. For information on a newer soil treatment using pvc pipe, see link below.
Whitcomb Iron Chlorosis Treatment, University of Nebraska- Lincoln Extension
10. Natural needle drop of evergreens occurs as older, inner needles turning yellow in September and October. Evergreens do not keep their needles indefinitely but drop them after one to many years. Pines, spruce and arborvitae vary in the number of years they keep their needles. For example, Ponderosa and Scotch pines usually keep their needles for three years. However, this may vary from tree to tree and year to year. Also, this process may be gradual or all the needles may turn at once. If the process is sudden, people become concerned about their trees health; however, natural need drop is not harmful to evergreen conifers.
Natural Needle Drop, University of Nebraska- Lincoln Extension
11. Dividing perennials is best accomplished by mid October in eastern Nebraska and early October in western Nebraska. As a general rule, divide spring blooming perennials during fall. Divide fall blooming perennials during spring. Divide summer blooming perennials during spring or fall.
12. Wait to apply winter mulch until after the soil begins to freeze or after night time temperatures are consistently dropping into the 20 degree F. range, usually in November. Winter protection protects plants against wide soil temperature fluctuations and temperature extremes. Use a 12 inch layer of coarse mulch over the tops of plants. Encircling plants or beds with chicken wire and filling the chicken wire with coarse mulch, such as wood chips, works well.
13. Harvest sweet potatoes just before or immediately after the first frost. If frost occurs before harvesting, cut the foliage off quickly. Dig carefully to avoid damaging sweet potatoes. Handle with care as roots bruise easily. Cure in a warm, airy place for one week if 80 degrees F or for two weeks if 75 degrees F. Store sweet potatoes at 55 to 60 degrees F. under moist conditions. To maintain moisture, individually wrap roots in newspaper and store in a cardboard box. Storage temperatures should not drop below 50 degrees F.
14. Vegetables can be stored for fairly long periods if undamaged produce is stored at the correct temperature and humidity levels; and produce is cured prior to storage where necessary. See publication for information on specific vegetables.
Vegetable Harvest and Storage, University of Missouri Extension
15. Dimpled apples are often due to feeding by tarnished plant bugs. This fall, manage broadleaf weeds near apple trees to help reduce overwintering populations. Next season, monitor for tarnished plant bug populations to determine the need to apply insecticides. Critical time for insecticide application is at petal drop.
16. Winter mulch for strawberries is best applied once night time temperatures are consistently dropping into the 20 degree F. range, usually in November. Winter protection protects plants from wide soil temperature fluctuations and temperature extremes. Use a 12 to 18 inch layer of coarse mulch, such as straw, over the tops of strawberries.
17. Late Blight of Potatoes and Tomatoes was promoted by cooler than average and moist conditions. Late blight causes tomato fruit and potato tubers to rot after harvest and in storage. On tomato fruit, a dark, greasy-looking lesion appears that quickly, within two days, expands to a soft rot of the whole fruit. On potatoes, tubers may look fine at harvest but rot in storage. Fungicides are available to treat the disease, but must be applied immediately after symptoms are spotted and according to label direction. Gardeners with infected plants this year should remove them and discard them immediately. Stored tomatoes, and especially potatoes, should be monitored closely for rotting.
Potato and Tomato Late Blight, Ohio State University
18. Woodpeckers pecking on houses are usually looking for food and attempting to reach insects that have crawled beneath siding. Insecticides will not reach these insects. If needed, block woodpeckers from siding by using netting or some other form of exclusion.
Stopping woodpeckers from pecking on houses, eXtension- National Cooperative Extension System
| Current Problems: | Major Symptom: |
| Lawns | |
| 1. Late fall fertilization | Use fertilizer with at least 50% slow release nitrogen |
| 2. Fall irrigation | Keep root zone moist, not saturated, during fall |
| 3. Rake or mow tree leaves often | Avoid leaves laying on turfgrass for more than 3 to 4 days |
| 4. Avoid walking on frozen turf | Repeat traffic will permanently damage dormant grass |
| Trees & Shrubs | |
| 5. Fall fertilization | Not needed for trees growing in fertilized lawns |
| 6. Fall irrigation | Keep root zone moist, not saturated, during fall |
| 7. Pruning time | During dormancy for shade trees; spring for most evergreens |
| 8. Protection from wildlife | Time to put exclusion methods in place |
| 9. Iron chlorosis | Tree and shrub leaves light green to yellow with darker green veins |
| 10. Natural needle drop of evergreens | Interior needles of evergreens turn yellow & drop off easily |
| Landscape Ornamentals | |
| 11. Stop dividing perennials | Most perennials should be divided/transplanted by mid October |
| 12. Wait to apply winter mulch | Winter mulch is best applied in November when soil freezes |
| Vegetables & Fruits | |
| 13. Harvesting sweet potatoes | Harvest immediately after a frost |
| 14. Storing produce | Correct temperature and humidity levels are required |
| 15. Dimpled apples | Tarnished plant bug feeding |
| 16. Mulching strawberries | Winter mulch is best applied sometime in November |
| 17. Late blight | Check stored potatoes and tomatoes often for rotting |
| Other | |
| 18. Woodpeckers pecking houses | Feeding on insects overwintering beneath siding |
1. Late fall fertilization is important for cool season turfgrasses (Kentucky bluegrass and tall fescue). It promotes root and rhizome growth and carbohydrate storage within the plant. Use a fertilizer where at least 50% of the nitrogen is from a slow release source to avoid promoting growth going into winter. Apply fertilizers at the time of the last mowing in late October or early November at a rate of 1 to 1.5 pounds of nitrogen per 1000 square feet.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
Kentucky Bluegrass Lawn Calendar, University of Nebraska- Lincoln Extension
Tall Fescue Lawn Calendar, University of Nebraska- Lincoln Extension
2. Fall lawn irrigation, in the absence of rainfall, is important for maintaining a moist soil to support root and rhizome growth during fall and to help turfgrass withstand winter injuries. Turfgrass soils should remain moist, not saturated, well into fall. Irrigation systems must also be protected from freeze damage by draining them. Information on proper drainage procedures for home lawn irrigation systems with back flow preventers can be found on page 23 of the Integrated Turfgrass Management for the Northern Great Plains E.C.97-1557. A copy of this Extension circular is available at most UNL Extension offices.
3. Rake or mow tree leaves on a regular basis to avoid the build-up of leaves on turfgrass for longer than 3 to 4 days. If leaving leaves on turfgrass after mowing, mow when leaves are dry. Pulverize leaves by using a mulching mower or making two to three passes. After mowing, the pulverized leaves should not cover the turf but filter into turfgrass so green grass blades are exposed.
Mulch Them/Mow Them in Place
4. Avoid traffic on frozen turf or grass crowns will be damaged leaving foot prints or pathways that are very slow to recover during spring. Walking on frozen dormant turfgrass is most harmful.
5. Fall tree fertilization, if needed for trees growing away from fertilized lawns such as in a windbreak, should be done after trees go dormant later in fall. As a rule, trees growing in fertilized lawns should not be fertilized. Trees only require ½ pound of nitrogen per growing season. This amount is provided from lawn fertilization. Additional fertilizer is harmful to landscape trees.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
6. Fall tree irrigation is important to promote root growth and reduce winter dessication injury. Continue irrigation, in the absence of rainfall, until close to soil freeze. Water when air temperatures are above 40 degrees Fahrenheit and early enough in the day for water to soak into the ground to avoid water freezing on the surface at night. Moisten the soil eight inches deep at the drip line of the tree. Check soil before irrigating to avoid a saturated soil. Roots will not grow without oxygen.
7. Pruning of deciduous trees and shrubs is best done after the plants are dormant. Evergreens like Japanese Yew, Junipers and Arborvitae can be pruned when deciduous plants are pruned, but early spring is ideal. Prune spruce and fir from April to August. Prune pines just as new growth has occurred, sometime from mid-June to mid-July.
Pruning Mature Trees, International Society of Arboriculture
Pruning Evergreens, University of Nebraska- Lincoln Extension
8. Protection from wildlife. Barriers of hardware cloth placed around young trees and shrubs is the best means of protection from rabbit and vole damage. Make sure the barriers extend well above the usual snow line. Various taste repellants, such as Thiram or Millers Hot Sauce, can be effective in reducing deer and rabbit damage as long as animals have other food sources to turn to. Scent repellants, such as bags of human hair or bar soaps on a rope, have been shown to be effective in some situations.
Deer Damage Management, eXtension- National Cooperative Extension System
Vole Damage Management, eXtension- National Cooperative Extension System
Rabbit Damage Management, eXtension- National Cooperative Extension System
9. Iron Chlorosis causes leaves of trees and shrubs to be light green to yellow with darker green leaf veins. It is often due to a high or alkaline pH soil which reduces availability of iron or manganese to some plants. It is most common in pin oak and silver maple. Reports of an increase in chlorosis in plants other than pin oak and silver maple are being made. These plants include spirea, roses, red maple, and others. For trees, apply iron via soil treatment or trunk injection. For smaller plants, promote a healthy rooting environment and soil apply iron. For information on a newer soil treatment using pvc pipe, see link below.
Whitcomb Iron Chlorosis Treatment, University of Nebraska- Lincoln Extension
10. Natural needle drop of evergreens occurs as older, inner needles turning yellow in September and October. Evergreens do not keep their needles indefinitely but drop them after one to many years. Pines, spruce and arborvitae vary in the number of years they keep their needles. For example, Ponderosa and Scotch pines usually keep their needles for three years. However, this may vary from tree to tree and year to year. Also, this process may be gradual or all the needles may turn at once. If the process is sudden, people become concerned about their trees health; however, natural need drop is not harmful to evergreen conifers.
Natural Needle Drop, University of Nebraska- Lincoln Extension
11. Dividing perennials is best accomplished by mid October in eastern Nebraska and early October in western Nebraska. As a general rule, divide spring blooming perennials during fall. Divide fall blooming perennials during spring. Divide summer blooming perennials during spring or fall.
12. Wait to apply winter mulch until after the soil begins to freeze or after night time temperatures are consistently dropping into the 20 degree F. range, usually in November. Winter protection protects plants against wide soil temperature fluctuations and temperature extremes. Use a 12 inch layer of coarse mulch over the tops of plants. Encircling plants or beds with chicken wire and filling the chicken wire with coarse mulch, such as wood chips, works well.
13. Harvest sweet potatoes just before or immediately after the first frost. If frost occurs before harvesting, cut the foliage off quickly. Dig carefully to avoid damaging sweet potatoes. Handle with care as roots bruise easily. Cure in a warm, airy place for one week if 80 degrees F or for two weeks if 75 degrees F. Store sweet potatoes at 55 to 60 degrees F. under moist conditions. To maintain moisture, individually wrap roots in newspaper and store in a cardboard box. Storage temperatures should not drop below 50 degrees F.
14. Vegetables can be stored for fairly long periods if undamaged produce is stored at the correct temperature and humidity levels; and produce is cured prior to storage where necessary. See publication for information on specific vegetables.
Vegetable Harvest and Storage, University of Missouri Extension
15. Dimpled apples are often due to feeding by tarnished plant bugs. This fall, manage broadleaf weeds near apple trees to help reduce overwintering populations. Next season, monitor for tarnished plant bug populations to determine the need to apply insecticides. Critical time for insecticide application is at petal drop.
16. Winter mulch for strawberries is best applied once night time temperatures are consistently dropping into the 20 degree F. range, usually in November. Winter protection protects plants from wide soil temperature fluctuations and temperature extremes. Use a 12 to 18 inch layer of coarse mulch, such as straw, over the tops of strawberries.
17. Late Blight of Potatoes and Tomatoes was promoted by cooler than average and moist conditions. Late blight causes tomato fruit and potato tubers to rot after harvest and in storage. On tomato fruit, a dark, greasy-looking lesion appears that quickly, within two days, expands to a soft rot of the whole fruit. On potatoes, tubers may look fine at harvest but rot in storage. Fungicides are available to treat the disease, but must be applied immediately after symptoms are spotted and according to label direction. Gardeners with infected plants this year should remove them and discard them immediately. Stored tomatoes, and especially potatoes, should be monitored closely for rotting.
Potato and Tomato Late Blight, Ohio State University
18. Woodpeckers pecking on houses are usually looking for food and attempting to reach insects that have crawled beneath siding. Insecticides will not reach these insects. If needed, block woodpeckers from siding by using netting or some other form of exclusion.
Stopping woodpeckers from pecking on houses, eXtension- National Cooperative Extension System
