Hort Update for the week of 10/26/2009
Bolded items are new in this issue of Hort Update
1. Winterizer fertilizers are important for Kentucky bluegrass and tall fescue. They are applied about the time of the last mowing, usually late October/early November. Nitrogen, applied at a rate of 1 to 1.5 pounds per 1000 square feet, is the nutrient most needed. With few exceptions, soils in Nebraska have adequate levels of phosphorous and potassium. While these nutrients are common in winterizer products, they are usually not needed. Select a fertilizer with an analysis such as 25-5-5 and with at least 50% of the nitrogen being from a slow release source to avoid promoting growth going into winter.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
2. Late for Seeding Turfgrass: Tall fescue is best seeded by September 20 and Kentucky bluegrass by September 30. Seeding/overseeding after this time increases the risk of winter injury to seedling turfgrass. Questions may arise about seeding after the soil begins to freeze so the seed is in place to begin growth next spring. This is not recommended. It is best to now wait until spring to seed/overseed cool season turfgrass.
3. Winterize irrigation systems need to 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.
4. 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
5. 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.
6. Anti-transpirants, i.e. Wilt-Pruf, can help plants endure stressful periods. The most common types are an emulsion of wax, latex, or plastic that forms thin films on foliage to minimize water loss from plants. We recommend their use on evergreen conifers or broadleaf evergreens growing in stressful sites and usually during winter only. They can benefit newly transplanted trees. Select the right product for the plant species as there are toxicity issues. Read and follow label directions. Apply them once every six weeks in mid to late November, early January, and mid to late February. Avoid covering plants so much that they become sticky with needles glued together. Have warm, soapy water nearby and clean out the sprayer immediately or the sprayer may be ruined by the product.
7. Multiple Season Interest Plantings. When selecting landscape plants, those that provide interest during more the one season are good choices. A plant that is beautiful for one or two weeks while blooming, but not highly ornamental the rest of the year is not as valued for landscapes. Now is a good time to evaluate landscapes for interest during fall and winter season. Make note of plants that, along with providing interest to the landscape this past spring and summer, now have good fall color; are still green after the hard freeze; have interesting seed heads or fruit that will cling to the plant through winter; or have attractive bark or branch patterns; and so on. With limited space, landscape plants that provide interest in multiple seasons are good choices.
8. 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
9. Fall tree irrigation is important to promote root growth and reduce winter desiccation 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.
10. 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 repellents, 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 repellents, 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
11. Cutting back herbaceous perennials can be done once the foliage naturally yellows and dies or any time after the foliage is killed by frost. As long as foliage is green, the plant may still be moving stored food into roots and other underground structures for winter storage. Perennials with winter interest can be left and cut back in early spring just before new growth begins. Any perennial that had a disease or insect problem during the season is best cut back to avoid overwintering the pest problem. Cut plants to two to three inches above the crown or growing point of the plant.
Fall and Winter Care of Perennials, University of Illinois Extension
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. Garden planning for rotation is important to reduce pest problems. If a garden plan was not made in spring, make note on paper now what crops were grown where in the garden so crop rotation can be used next spring. Ideally, rotate between families of vegetables. While not feasible in most home gardens, a two to three year rotation is best.
14. 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
15. Safe Pesticide Storage. Read and follow label directions for correct storage conditions. Store pesticides in original containers only. Store pesticides in locations away from water sources and in places not easily flooded after a heavy rainfall. Make sure the storage building is in good repair, doesn't leak and has sturdy shelving. Store pesticides out of reach of children and out of potential paths of runoff or flood water. Buy only the estimated amount needed in a season to avoid storing larger quantities for a longer period of time.
Pesticide Use in the Lawn and Garden, University of Nebraska- Lincoln Extension
16. Fall invaders are nuisance pests that accidentally invade homes looking for overwintering sites. Common invaders this year are millipedes and MALBS (multi-colored Asian lady beetles) but also include boxelder bugs, crickets, spiders, hackberry psyllids and others. Exclude fall invaders by caulking cracks and crevices and using weather stripping and tight fitting doors and screens. Indoors sweep or vacuum fall invaders. A ten to fifteen foot side strip around the homes foundation can be treated with insecticide to reduce fall invaders. When vacuuming large numbers of MALBS, precautions must be taken to avoid unpleasant aromas. See the link for precautions.
Multi-Colored Asian Lady Beetles, Ohio State University
Bolded items are new in this issue of Hort Update
| Lawns | Major Symptom: |
| 1. Winterizer fertilization | Nitrogen, not phosphorous most needed in late October |
| 2. Late for seeding | September or April into May ideal time for cool season grasses |
| 3. Winterize irrigation systems | See instructions in EC97-1557 Integrated Turfgrass Management |
| 4. Rake or mow tree leaves often | Avoid heavy later on turfgrass for more than 3 to 4 days |
| 5. Avoid walking on frozen turf | Repeat traffic will permanently damage dormant grass |
| Trees & Shrubs | |
| 6. Anti-transpirants | Apply in November; repeat application twice during winter |
| 7. Multiple season interest planting | Make note of plants with fall color/winter interest |
| 8. Fall tree fertilization | Trees growing in fertilized lawns do not require fertilization |
| 9. Fall tree irrigation | Keep root zone (8” deep & beyond drip line) moist, not saturated |
| 10. Protection from wildlife | Time to install exclusion methods; too early for repellents |
| Landscape Ornamentals | |
| 11. Cut back herbaceous perennials | Once foliage is frosted/yellowed, it can be removed |
| 12. Wait to apply winter mulch | Winter mulch best applied after soils begin to freeze |
| Vegetables & Fruits | |
| 13. Garden planning & rotation | Make note of planting locations of each crop & any problems |
| 14. Stored potatoes & late blight | Check stored potatoes often for tuber rot |
| Other | |
| 15. Pesticide storage | Read label directions for safe storage during winter |
| 16. Fall insect invaders | Nuisance pests. Exclude with caulking; vacuum indoors |
1. Winterizer fertilizers are important for Kentucky bluegrass and tall fescue. They are applied about the time of the last mowing, usually late October/early November. Nitrogen, applied at a rate of 1 to 1.5 pounds per 1000 square feet, is the nutrient most needed. With few exceptions, soils in Nebraska have adequate levels of phosphorous and potassium. While these nutrients are common in winterizer products, they are usually not needed. Select a fertilizer with an analysis such as 25-5-5 and with at least 50% of the nitrogen being from a slow release source to avoid promoting growth going into winter.
Fertilizer Use in Home Landscapes, University of Nebraska- Lincoln Extension
2. Late for Seeding Turfgrass: Tall fescue is best seeded by September 20 and Kentucky bluegrass by September 30. Seeding/overseeding after this time increases the risk of winter injury to seedling turfgrass. Questions may arise about seeding after the soil begins to freeze so the seed is in place to begin growth next spring. This is not recommended. It is best to now wait until spring to seed/overseed cool season turfgrass.
3. Winterize irrigation systems need to 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.
4. 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
5. 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.
6. Anti-transpirants, i.e. Wilt-Pruf, can help plants endure stressful periods. The most common types are an emulsion of wax, latex, or plastic that forms thin films on foliage to minimize water loss from plants. We recommend their use on evergreen conifers or broadleaf evergreens growing in stressful sites and usually during winter only. They can benefit newly transplanted trees. Select the right product for the plant species as there are toxicity issues. Read and follow label directions. Apply them once every six weeks in mid to late November, early January, and mid to late February. Avoid covering plants so much that they become sticky with needles glued together. Have warm, soapy water nearby and clean out the sprayer immediately or the sprayer may be ruined by the product.
7. Multiple Season Interest Plantings. When selecting landscape plants, those that provide interest during more the one season are good choices. A plant that is beautiful for one or two weeks while blooming, but not highly ornamental the rest of the year is not as valued for landscapes. Now is a good time to evaluate landscapes for interest during fall and winter season. Make note of plants that, along with providing interest to the landscape this past spring and summer, now have good fall color; are still green after the hard freeze; have interesting seed heads or fruit that will cling to the plant through winter; or have attractive bark or branch patterns; and so on. With limited space, landscape plants that provide interest in multiple seasons are good choices.
8. 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
9. Fall tree irrigation is important to promote root growth and reduce winter desiccation 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.
10. 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 repellents, 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 repellents, 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
11. Cutting back herbaceous perennials can be done once the foliage naturally yellows and dies or any time after the foliage is killed by frost. As long as foliage is green, the plant may still be moving stored food into roots and other underground structures for winter storage. Perennials with winter interest can be left and cut back in early spring just before new growth begins. Any perennial that had a disease or insect problem during the season is best cut back to avoid overwintering the pest problem. Cut plants to two to three inches above the crown or growing point of the plant.
Fall and Winter Care of Perennials, University of Illinois Extension
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. Garden planning for rotation is important to reduce pest problems. If a garden plan was not made in spring, make note on paper now what crops were grown where in the garden so crop rotation can be used next spring. Ideally, rotate between families of vegetables. While not feasible in most home gardens, a two to three year rotation is best.
14. 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
15. Safe Pesticide Storage. Read and follow label directions for correct storage conditions. Store pesticides in original containers only. Store pesticides in locations away from water sources and in places not easily flooded after a heavy rainfall. Make sure the storage building is in good repair, doesn't leak and has sturdy shelving. Store pesticides out of reach of children and out of potential paths of runoff or flood water. Buy only the estimated amount needed in a season to avoid storing larger quantities for a longer period of time.
Pesticide Use in the Lawn and Garden, University of Nebraska- Lincoln Extension
16. Fall invaders are nuisance pests that accidentally invade homes looking for overwintering sites. Common invaders this year are millipedes and MALBS (multi-colored Asian lady beetles) but also include boxelder bugs, crickets, spiders, hackberry psyllids and others. Exclude fall invaders by caulking cracks and crevices and using weather stripping and tight fitting doors and screens. Indoors sweep or vacuum fall invaders. A ten to fifteen foot side strip around the homes foundation can be treated with insecticide to reduce fall invaders. When vacuuming large numbers of MALBS, precautions must be taken to avoid unpleasant aromas. See the link for precautions.
Multi-Colored Asian Lady Beetles, Ohio State University
