Best Lawns News. Late Summer 2014 Edition Virginia Cooperative Extension Prince William Unit. Featured in This Issue

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1 Best Lawns News Late Summer 2014 Edition Virginia Cooperative Extension Prince William Unit Featured in This Issue Better Know A Weed: Lespedeza 2 Fall Renovation of Cool Season Turf 4 Virginia Fertilizer Regulations Update 7 How to Read a Seed Label 9 All content was written by Thomas Bolles, except where noted, and is based on university research at Virginia Tech, Virginia State and other partner universities in the Land Grant system. Staff contact information Paige Thacker, Extension Agent, Horticulture Phone: pthacker@pwcgov.org Nancy Berlin, Natural Resource Specialist/Master Gardener Coordinator Phone: nberlin@pwcgov.org Thomas Bolles, Environmental Education Specialist/BEST Lawns Coordinator Phone: tbolles@pwcgov.org Jennifer Graham, Administrative Assistant Phone: jgraham@pwcgov.org VIRGINIA COOPERATIVE EXTENSION 8033 Ashton Avenue, Suite 105 Manassas, VA Phone: Fax: Disclaimer Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products which also may be suitable.

2 Lespedeza Common lespedeza (Lespedeza striata (Thunb.) Schind) is a troublesome warm season annual that plagues many lawns in our area. Other names for common lespedeza include Japanese clover and annual lespedeza. It typically occurs in lawns from May into October. Lespedeza has three smooth, oblong leaflets with parallel veins that are nearly perpendicular to the midvein. It has wide spreading prostrate branches. Branches often have downward pointing hairs. As the plant matures, the stems harden and become woody. Lespedeza flowers are pink to purple in color. The flowers are also small and often go unnoticed. Lespedeza tends to grow lower than fescue and Kentucky bluegrass, but one should not be tempted to lower mowing heights. Mowing high, especially in spring when lespedeza is germinating, gives turf the competitive edge against this weed. Where turf is thick and mowed high, it can shade out newly germinating lespedeza. High turf also provides grass plants with more photosynthetic capacity, which can help grass remain competitive with lespedeza and other weeds. Lespedeza is often found in compacted soils. Core aeration can help reduce compaction in the lawn. When battling lespedeza, aeration should only be done in the fall. Spring aeration weakens turf roots and gives newly sprouted lespedeza a better opportunity to infest the lawn.

3 Lespedeza in Flower Note the size of the flower compared to the leaves. Lespedeza has a tap root so turf needs a deep root system to compete for water. If irrigating over the summer, deep, infrequent watering (1 inch once a week) will promote deep turf roots. Frequent watering and overwatering, especially in shady situations, can encourage lespedeza. In non-irrigated lawns, lespedeza can do well under very dry conditions. Removing lespedeza is not easy. Hand pulling can work on small areas, but it can be labor intensive. Chemical controls are available, but lespedeza is tolerant of many broadleaf herbicides. Three-way post-emergent herbicides* are recommended. Be sure to read all label instructions. Late spring/early summer applications allow herbicides to attack lespedeza while it s young and more vulnerable. It may take some time for an herbicide to kill the weed. In a University of Arkansas study, it took 71 days to kill 83% of lespedeza in test stands. Repeat applications may also be needed to achieve acceptable levels of control. * Please Note: For specific herbicide recommendations, for this or any weed, please contact the Prince William VCE Horticulture Help Desk ( or master_gardener@pwcgov.org). It s hard for many to find an upside to lespedeza in the lawn, but there are a few positive things about lespedeza. Lespedeza is a legume and can add some nitrogen into the soil for turf. Lespedeza s wood stems may add a degree of wear resistance to the lawn, particularly in high traffic areas. Many lespedeza infested lawns look good from a distance because of lespedeza s dark green color. Like it or hate it, lespedeza loves the compact urban soils and dry summers of Northern Virginia. Prevention is the best option for controlling this weed. Cultural practices to keep turf healthy and thick will help keep lespedeza in check. Knowing what lespedeza s life cycle and what it looks like can help stop lespedeza invasions before they overtake a lawn. Please Read and Follow All Label Directions for Any Pesticide You Choose to Use is the International Year of the Family Farmer Prince William and other nearby counties are home to many family farms. Support local farmers by visiting farmers markets, farm stands and pickyour-own farms across the region.

4 Fall Renovation of Cool Season Turf Fall is the time to renovate cool season turf. September through early October is the ideal window for planting but, with a little cooperation from Mother Nature, planting into November can still result in successful establishment of new grass. Sooner in the season is usually preferred to later in the season because cool season turf puts much of it s growth energy into the roots. Establishing a good root system is critical for new grass to surviving the following year. Renovation can vary from a patch repair of a damaged section of turf to overseeding to replanting the entire lawn. Deciding which option is best is sometimes obvious and sometime not. The traditional rule of thumb is to replant if weeds make up over 50% of the lawn. At that point, it s often less expensive in the long run to start over with a new lawn than to be continually battling well established weed populations. Since replanting is more costly than overseeding in the short run, the closer a lawn is to the grass vs weeds mark, the more of a judgment call it is for the homeowner to decide which option will best suit their situation. Seed v Sod When renovating the lawn, you have the option of using seed or sod. Seed can be used to overseed, patch repair or replant the entire lawn. It s relatively inexpensive compared to sod but it takes longer to establish. Sod is typically used when replanting a lawn or in repairing patches of damaged turf. With seed or sod using fresh product and maintaining proper moisture through establishment is key to being successful. To determine seed freshness, inspect the label. The area on the label that lists the species and cultivars of the seed should also have a date that the seed was germination tested. Look for seed that was tested less than a year before you plant. The viability of turf seed begins to drop significantly after a year. Quality seed is readily available for cool season grasses. Select species that are appropriate for the site where it will be used. For more information on choosing seed, see How to Read a Seed Label on page 9 below. Fresh sod is ideally harvested the morning when it will be installed. From harvest to installation, sod should be kept moist to protect the roots. There are a number of sod producers in the Northern Virginia area who will sell fresh sod directly to homeowners. Overseeding the Lawn Overseeding can prevent a lawn from thinning as it ages and introduce the latest proven varieties into the lawn. Weed control can be a part of overseeding. If using herbicides on weeds, it s important to take into account the wait time between when a pesticide is applied and when it safe to seed. This information can be found on the product label. Because grass seedlings can be shaded out, it s important to gradually lower the height of the lawn to about 2.5 inches. This will open the canopy and allow newly sprouted grass access to light when they need it most. Soil preparation consists of core aeration, followed by an application of fertilizer, ¼-½ inch of organic material (typically compost) and, if called for by a soil test, an application of lime. Because there is existing turf, the seeding rate is lower than in other situations. Lawns that are all tall fescue or tall fescue mixed with either bluegrass or fine fescue are typically overseeded at rate of 3-4 lb. per 1,000 sf. Seed should split into two batches. Each batch should be spread in a

5 direction perpendicular to the other to maximize seed distribution. Seed should be raked in to increase seed to soil contact. Patch Repairs Patch repairs are used to repair sections of turf that have died or overtaken with weeds. As with overseeding, weed control is an issue. Repairing a patch that was inundated by summer weeds allows for the careful use of a non-selective glyphosate herbicide to remove all vegetation in the area to be patched. Avoid products with Extended Control as it lingers in the soil and can prevent grass seed from germinating. Care should be taken to ensure the herbicide does not drift outside the patch area as these herbicides will damage the existing turf and ornamentals. Once all the dead plant material has been removed, soil preparation can begin. The soil should be amended as described in the overseeding section above. If the lawn is not aerated however, a bow rake should be used to rough up the surface. Seed and sod both need to have good contact with the under laying soil to establish successfully. Patched repairs use a seeding rate of 6-8 lb per 1,000 sf. Repaired areas should be lightly mulched at a rate of 1-2 bales per 1,000 sf, leaving about half of the ground should be visible through the straw. Replanting the Lawn When replanting the entire lawn, all existing grass and weeds should be killed. Weeds. This is normally done with a non-selective glyphosate herbicide. As mentioned above, this type of herbicide can harm ornamentals so it should be used with care. Soil preparation involves tilling to a depth of 6-8 inches. Fertilizer, lime (if needed) and compost should be tilled into the soil any this time. Tilling provides an excellent opportunity to get more organic matter into the soil. Research shows adding 1-2 inches of compost prior to planting will allow the turf to establish much more quickly. Once the amendments have been tilled in, the soil should be leveled and smoothed with a rake. Tall fescue or tall fescue mixes are seeded at rate of 6-8 lb. per 1,000 sf. Seed should be applied as described in the overseeding section above. The area should be lightly mulched with straw at a rate of 1-2 bales per 1,000 sf. When sod is used, the soil is pre-moistened. Planting begins against a straight line. This is usually a sidewalk or a driveway. Sod pieces are laid in an alternating, brick-like pattern. Pieces should fit tightly against each other. When sod is laid on slopes, sod pieces are laid perpendicular to the slope. Once laid, sod is often rolled or tamped to ensure good root to soil contact. Laying Sod on a Slope (L) and Installing and Tamping Sod (R)

6 Post Planting Care With both seed and sod, it is important to keep the soil moist. This may involve multiple light applications of water per day, depending on the weather. As the roots develop, gradually shift to watering more deeply and infrequently. Ideally, the turf should get a total of 1 inch of water applied once a week. Avoid walking on new sod and overseeded lawns as much as possible for at least 3 weeks. With a complete replanting of the lawn with seed, avoid foot traffic as much as possible until the new grass has been mowed at least 3 times. With renovation fertilizer is applied pre-planting, fertilizer should not be applied again for at least 30 days. With sod, this means 30 days after installation. With seed, this means 30 days after the new grass has sprouted. Young grass can be sensitive to fertilizer burn and does not need as much fertilizer as established turf so it is not always necessary to apply additional fertilizer after the initial pre-planting application especially if cloudy/rainy conditions dominate the weather and turf growth is slowed by reduced sunlight. Newly seeded turf can be harmed by pesticides that normally wouldn t harm mature turf. If pesticides are used after seeding, the product label should be consulted. Many pesticides have two wait periods related to seeding. One period is between when a product is used and when that area can be seeded. The other period is between when grass is seeded and when the product can be safely applied on the new grass. These wait periods are rarely the same. If the label is unclear, check with the product manufacturer. Maintaining proper mowing heights will help deter weeds. Proper fertilization will help new grass stay healthy and competitive against weeds. Regular soil testing helps ensure the appropriate type of fertilizer is used and an appropriate soil ph is maintained. Fertilizing in the fall and avoiding fertilizing in the spring can reduce the likelihood and severity of brown patch disease over the summer. The Prince William VCE office offers soil test kits and nutrient management plans for turf through the BEST Lawns program. For more information on BEST Lawns, call or the office at or BESTLawns@pwcgov.org. Looking for a Great Day of Fun Outside? Check Out These Free Admission Days This Fall Sept. 27 National Public Lands Day, free admission to National Parks, National Forests and National Wildlife Refuges Oct. 12 Opening day for National Wildlife Refuge Week free admission to National Wildlife Refuges Nov. 11 Veterans Day, free admission to National Parks and National Wildlife Refuges Nov Veterans Day Weekend, free admission to National Forests

7 Fertilizer Regulations Update Earlier this year, the Virginia General Assembly passed a bill changing the fertilizer regulations that relate to fertilizing turf. These changes reduce the amount of nitrogen that can be applied within a 30 day period. These changes were went into effect in July Turf Type Maximum lb. N per 1,000 sf per 30 Day Period Readily Available Nitrogen Nitrogen Sources with over 15% Slow Release N Cool Season 0.7 lb N per application 0.9 lb N per application Warm Season 0.7 lb N per application 1.0 lb N per application The old rates were 1.0 lb. N per 1,000 sf per month. Urban nutrient plans written before the new guidelines went into effect will continue to be valid with fertilizer rates using the application rates as written in the plan until the plans expire. The new rates depend on the amount of slow release nitrogen in the bag to determine at what rate it should be applied. If at least 15% of the total nitrogen in a fertilizer is slow release nitrogen, that fertilizer can be applied at a rate of 0.9 lb. N per 1,000 sf. Fertilizers that don t meet the 15% minimum must be applied at the 0.7 lb. N per 1,000 sf rate. In a practical sense, the change means that consumers need to be more aware of what forms of nitrogen are in the bag of fertilizer they use. It gets confusing as there are a number of broad terms used to describe nitrogen that mean approximately the same thing. Readily available nitrogen (RAN) is also called water soluble nitrogen (WSN) or quick release nitrogen. Slow release nitrogen (SRN) can be referred to as slowly available nitrogen (SAN) and water insoluble nitrogen (WIN). Readily available nitrogen sources include ammoniacal nitrogen, ammonium nitrate, urea, ammonium sulfate and potassium nitrate. Slow release nitrogen sources include urea formaldehydes (UF), methylene urea (MU), isobutylidene diurea (IBDU) and coated ureas. Most organic fertilizers are also considered slow release. UF, MU and IBDU rely on weather and soil conditions to breakdown the compounds and release the urea. Sulfur coated urea has a coating that must break down over time through microbial action so the urea is released gradually. Polymer coated urea has a coating with tiny pores that allow water in to slowly dissolve and leak out the urea over time. Polymer coated products depend on moisture and temperature to determine the rate of break down. Some ureas are coated with both sulfur and polymer. Slow release organic nitrogen sources rely on microbial action to free the nitrogen and convert it into forms usable by plants. It would be simple if fertilizer bags plainly listed the amounts of readily available and slow release nitrogen, but they don t always do so. It s is not always clear and the fine print is important. Many turf maintenance fertilizers meet the 15% slowly available nitrogen criteria that allow lawn fertilizer to be applied at the higher rate. Being able to recognize these fertilizers can result in fewer overall applications without sacrificing turf quality.

8 The percentage of the total nitrogen that is slow release equals the percentage of the product that is slow release nitrogen divided by the total nitrogen in the product. Ammoniacal nitrogen and urea are both soluble nitrogen. At a quick glance, this appears to be all readily available nitrogen. However, the fine print says 16.3% of the nitrogen in this fertilizer is from slowly available sources. Dividing the slowly available percentage (16.3%) by the total nitrogen percentage (24%) results in the percentage of the nitrogen that is slow release (67.9%) Since the 67.9% of the total nitrogen is slow release, the product can be used at the higher 0.9 lb. N per 1,000 sf in a 30 day period on cool season turf. In this example, there is 8% total nitrogen. 2.44% of the product is urea. The asterisk says 2.1% is coated urea. This means 26.2% of the nitrogen (2.1/8.0 = 26.2%) is slowly available, so this fertilizer can be applied at the higher rate. In this example, there is 13% nitrogen. All of it from readily available sources, so this product would have to be applied at the lower, 0.7 lb. N per 1,000 sf, application rate. Even with fertilizers that meet the 15% SAN standard, applying fertilizer at lower application rates is encouraged. The lower application rate reduces the potential for the nitrogen to leach into ground water or be carried into surface water by storm runoff. Nutrient plans with planning fertilizer rates and timings should be used for environmentally sensitive sites. Sensitive sites include lawns near water sources, on flood plains, with subsurface drains, with steep slopes, with highly leachable soils, with soils with a high potential for subsurface lateral flow and/or with shallow soils over limestone or fractured rock.

9 How to Read A Seed Label Seed labels, like fertilizer labels, contain a lot of valuable information that can help you make an informed purchase if you know what to how to interpret it. Sample Seed Label Freshness The starting point for reading the label is the freshness of the seed. Most turfgrass seed is tested for germination. Unlike many weed seeds, turfgrass seeds will quickly lose their viability after about a year. If the germination test was performed over a year before you intend to plant it, choose a different bag. Turf Varieties Consider the types of grass in the bag. Two things are important: the species of turf and the varieties themselves. Nature doesn t line monoculture and having a mix of cool season species and varieties can help give the lawn better overall resistance to the spreading of disease. Consider the lawn conditions to determine what might mix of species is best suited to available sunlight. A mix of tall fescue and either fine fescues or Kentucky bluegrass is the standard lawn mix in Northern Virginia. All grasses do well in full sun. Kentucky bluegrass has some tolerance to light shade. Fine fescues are our most shade tolerant turfgrass options. The fine fescues are red, hard, sheep and chewings fescues. Tall fescue s shade tolerance is between bluegrass and fine fescue. Shade mixes with a high percentage of bluegrass, is not likely to be successful in a shady lawn. A mix of tall and fine fescues is commonly used for shady lawns. A mix of tall fescue and Kentucky bluegrass is commonly used for sunny lawns.

10 Some grass seed mixes found in local stores may also have ryegrass in the mix. Ryegrass is not suited for home lawns in Northern Virginia because of it s limited heat tolerance. There are, however, situations when using ryegrass is appropriate. One of those is when seeding. Ryegrass will germinate in a few days, fescues germinate in a week to 10 days and bluegrass can take over 3 weeks to germinate. Having a small percentage of rye in a seed mix will give quick cover to fall seeded lawn that will protect the other species from being washed away by storm events before they germinate. This is especially useful when reseeding slopes. When buying multiple bags of seed, read the label of each bag! Many times a store will get a shipment of seed bags from a manufacturer with the same brand but with different seed mixes in the bag. For example, one bag of Acro Sun and Shade Mix may be 90% tall fescue and 10% Kentucky bluegrass, while another bag of Acro Sun and Shade Mix on the same shelf will have 62% tall fescue, 30% perennial rye, and 8% red fescue. Virginia Tech publishes a list of recommended turfgrass varieties annually. This can be found online at pubs.ext.vt.edu/cses/cses-17/cses-17_pdf.pdf. The variety recommendations are based on ongoing research at test plots in Virginia and Maryland to determine which varieties do best in our region. It can be difficult to find a seed mix that contains all recommended varieties. Look for mixes that contain at least of some of the recommended varieties, if possible. Keep in mind that just because a variety is not on the recommended list, doesn t mean it will do poorly. Some varieties don t make the list because they were not tested. Some varieties drop off the list because an improved version has come along. For example, the tall fescue varieties Falcon V and Falcon IV are on the recommended varieties list replacing Falcon III, which had been on previous lists. Purity Another key piece of information is the purity. Purity is measured in percentage of everything in the bag by weight. Pay attention to the percentages. When the percentages of each variety are total, the species ratio should be about 90% tall fescue and 10% other species. In addition to the listed varieties, other items listed will include other crop seed, weed seed and inert matter. Other crop seed is turfgrass seed whose variety or species couldn t be identified. Weed seed is just what it says. It s included because sometimes it s not economical to try to sort weed seed out. If noxious weed seeds are present in the bag they are listed by the species and the approximate number of seeds per pound (not percentage) in the bag. In the example below, 27 seeds per pound translates to the possibility of introducing 216 Poa annua (annual bluegrass) plants per 1,000 sf in a newly seeded lawn. Ideally, the weed seed percentage should be zero or in the 100 ths of a percent. Inert material is usually filler of some kind. In patch repair mixes, the inert matter is often a mulch to protect the seed and retain moisture. If fertilizer is added to the mix, it will be listed. Remember if there is fertilizer in the seed mix, that nitrogen should be accounted for when making your pre-planting fertilizer application. Several companies have introduced coated seed to help with moisture retention and/or provide some fertilizer.

11 Pay attention to percentages or you may end up buying less seed than you need. Notice in the label below that in this 7 lb bag, there is only 3.38 lb. of seed in the bag. There is also 0.49 lb. of nitrogen in the seed coating that needs to be considered when planning nutrient applications. Germination Percentage and PLS Seed labels show the results of germination testing, expressed as a percentage. For most cool season grass species, it s recommended to use seed that tests as high as possible. Finding seed with germination rates in the 90% or greater range can be a challenge at times. A few years ago bad weather in the Pacific Northwest (where most grass seed is produced) made seed supplies short and there were seed bags sold with seed that only tested as low as 50% germination. Germination is important to know when calculating how much seed to buy. Seeding rates are based on pure live seed (PLS). PLS is easy to calculate: PLS = % of Germination x % of Purity 100. Compare the labels below: The 20 lb bag of Ultimate Seed Mix (left) is 96% turfgrass varieties which all tested at 80% germination. This means 76.8% of the bag (15.36 lb.) is PLS. The Dense Shade Mix (left) is 47.74% turfgrass seed that germination tested at 85%. This 20 lb. bag only has 40.58% (8.11 lb.) of PLS. One mix isn t necessarily better than the other, but the Ultimate Seed Mix would cover about twice as much area as the Dense Shade Mix at the same application rate. Many factors go into successfully seeding a lawn. Seed choice is often determined more by brand recognition than what it is in the bag. Knowing how to read a seed bag can help make an informed choice about seed and greatly improve the chances of a successful planting.

12 VCE Schedule of Classes Master Gardener Saturdays in The Garden The Teaching Garden at St. Benedict Monastery 9:00 am to Noon September 6 th, October 4th September 6 - Weeds, Soil Health and Cover Crops Learn from VCE Staff & Master Gardener Volunteers how to improve your soil, identify weeds and use cover crops effectively. October 4 - Tree identification Join Arborist, Julie Flanagan, for a class on tree identification from 9 11:30 am. Storing homegrown produce The Cooks Garden Volunteers will give you tips for storing your homegrown produce from 11:30-12 noon. Master Gardener Clinics at Manassas City and Dale City Farmers Markets Ask a Master Gardener your Gardening Questions Manassas City Farmers Market Dale City Farmers Market Saturdays 10 am to 1 pm Sundays 10 am to 1 pm August 16 August 17 August 30 August 31 September 13 September 14 September 27 September 28 October 4 October 12 October 18 October 26 Other Opportunities Introduction to the Prince William County Master Gardener Program Find out about becoming a Master Gardener Volunteer with Virginia Cooperative Extension. Please register and plan to attend one of the information sessions: Monday, August 25-6:30-8 pm - Development Services Building Room 202 A & B - 5 County Complex Court, Prince William, or Wednesday, August 27-6:30-8 pm - McCoy Room at Sudley North Government Building 7987 Ashton Avenue, Manassas Ten Steps to a Greener Lawn Call today to schedule a Ten Steps to a Greener Lawn class for your homeowners association or community group, this class teaches how to have a beautiful lawn with less cost to you and the environment! Contact us at bestlawns@pwcgov.org or You can also receive information on our BEST Lawns (Building Environmentally Sustainable Turf) program, a research-based program for lawn education from Virginia Cooperative Extension - Prince William. PLEASE NOTE: All Classes are of these programs are free. Registration is requested by calling or ing master_gardener@pwcgov.org