Turf maintenance can be intensive work. The results of your effort are often affected by things unseen. Small bugs, microscopic diseases and even the molecular composition of the soil can harm existing turf stands and ruin any hope of establishing new turf. It is important to understand whats going on in your field, lawn or park to be able to properly maintain the turf stand.
Below are outlined cultural practices that will help ensure the continued health of your turf stand. Also discussed are some common problems and the solutions.
Soil testing is an important first step to developing a maintenance program. It is important to know where you are starting from and where you should aim to be. A soil test can be done through either the University of Maine’s Soil Testing Service or through Sports Fields, Inc. and Harris Laboratories, Inc.
The lab will prepare a report on the submitted soil sample. The report will discuss the:
-Soil type: the soil in and under your ball field, lawn or golf green is one of the most important pieces of the turf stand and one of the hardest and most expensive to change. When building a new turf surface, it is important to select the proper blend of sand, silt and clay for your application. Sand drains water away rapidly, but also allows nutrients to leach down into the soil below the root zone. Silt and clay hold water and nutrients but are prone to compaction.
-Soil pH: soil pH is the acidity or alkalinity of the in the sample. For athletic turf and other fine turf stands the desirable range is slightly acidic, in the 6.0-6.5 range. If the soil is out of this range some nutrients “lock up” in the soil and become unavailable to the grass plants. As part of the lab’s report a recommendation will be made on how to correct your soil’s pH.
-Soil Nutrients: the nutrients in the soil required for grass growth. The soil test report will show the amount of plant essential nutrients in the soil, and their availability to the plants. Recommendations will be made to correct deficiencies in available nutrients. These may include adjusting the soil pH, not just adding fertilizer.
Seedbed preparation is an important step in the seeding or sodding of a new or renovated surface.
Preparation is the same for seeding, sodding and hydroseeding.
- Start with a soil test.
- Remove debris and rocks.
- Ensure 4-6″ or rootzone mix above the under drain and subgrade material.
- Apply soil supplements like lime and fertilizer as specified in the soil test report.
- Rototill the rootzone mix.
- Rake the rootzone smooth with a York Rake or power rake.
- Apply starter fertilizer.
- Apply sod or seed, whether broadcast, applied mechanically or hydroseeded.
- Water. New seeding should be kept moist with frequent light watering. New sodding must be soaked through daily for the first week after installation. After 7 days watering can be cut back to a normal irrigation schedule.
Mowing new seeding or sodding can be done once the new growth is high enough to mow at the optimum height.
In Maine the turf stands on our playing fields and fine turf areas are ideally composed of cool season turf grasses. Each type of grass has its advantages and disadvantages.
Kentucky Bluegrass-The standard in athletic field turf, it is a resilient plant. It handles cool temperatures, compaction, and wear well and recuperates quickly. It performs best when well fertilized, and in open sunny areas. It is slow to establish, so while it makes a great playing surface it isn’t well suited for mid season repairs.
Perennial Ryegrass-Used heavily in athletic fields and lawns it performs well in high traffic areas. It doesn’t recover as well as Kentucky Bluegrass, but it germinates and establishes much quicker, making it an ideal choice for repairs to athletic fields made mid-season.
Creeping Bentgrass-Bentgrass makes a nice putting surface and is the grass type of choice for many golf course tees and greens; with a recommended height of cut below 1/2″. However, at the higher height of cut in lawns and athletic fields, bentgrass gets thatchy, crowds out more desirable turf, often making it a weed in athletic fields and lawns.
Tall Fescue-A great lawn grass, it is relatively safe from turf diseases, establishes quickly, and handles wear and compaction well.
Fine Fescues-Fine fescues include a variety of similar grass types. They require very little fertilizer and can handle significantly more shade than other turf grass types. However they do not handle traffic and compaction well.
Athletic turf should be maintained at a height of cut which will ensure its continued growth and provide a surface suitable for the activity taking place on the turf.
Frequency of mowing ideally depends on the growth, not a set schedule. Mowing should start in the spring as soon as the grass needs mowing and should continue into the fall until the grass stop growing. Mowing should not remove more than 1/3 of the grass leaf in any cut. If your desired height of cut is 2″ mowing should always occur before the grass grows above 3″. This will help avoid scalping the turf. Mowing directions and patterns should be varied. This keeps grass from being repeatedly rolled over the same direction and helps keep it growing upright. It also moves tire tracks and helps prevent compaction.
Ensure mower blades are kept sharp. Dull blades tear, rather than cut, the grass and cause damage to the blades. If possible clippings should be left on the turf. Clippings are up to 90% water, so unless they are excessive will quickly decompose. They also contain plant essential nutrients that can be returned to the rootzone.
Irrigation is an important consideration for turf and a near necessity for establishment of new seedings. Grass can’t germinate or grow without water. Established turf go into dormancy to survive through hot dry conditions with little water. It will brown out and become inactive, but will green back up when water returns. New seeding cannot germinate without water.
Irrigation comes in many forms. From a 5/8″ garden hose and sprinkler to a Kifco Water Reel above ground options provide portability, flexibility and lower up front costs. Automatic, in ground systems provide thorough coverage and can be run with no input from personnel on site. The goal of any system, no matter the option is to provide the water needed to keep an existing turf stand healthy, or to establish new plantings.
Turf grasses generally require 1-2″ of water per week. This varies depending on the soil type and the particular type of grass you are growing. The total water needed each week includes rain. In wet weather cut back on irrigation or stop it completely. You can over water turf. It is important to monitor irrigated stands of turf. Check root growth periodically. Shallow roots may mean you are irrigating to often.
It is ideal to irrigate at night, less water evaporates. You also don’t want to irrigate immediately before the turf is put under heavy use. This can be tricky on athletic fields during the season, but whenever possible don’t water for about 24 hours before a game or practice.
One of the great benefits to an irrigation system is the ability to syringe the turf. Syringing is a brief (1-2 minute) application of irrigation mid day on a hot, dry summer day. This helps cool the turf and helps prevent wilting.
Aeration is the mechanical process used to relieve soil compaction. Compacted soil has decreased drainage, air exchange and is harder for roots to grow in. Aeration helps with water percolation, and allows air, and soil additives like lime and fertilizer to more easily move down into the rootzone where it will be most effective. A variety of methods of aeration penetrate to varying depths in the soil. It is a good idea to vary aeration methods to avoid the forming of hard pans below the surface.
Aerating has 5 major benefits:
- Denser turf.
- Denser root growth and deeper root depth.
- Helps with the decomposition of the thatch layer.
- Reduces the likelihood of damage from pests.
- Improves the saftey of the playing surface.
Rule of thumb:
- Athletic fields should be aerated once a month when they are in use.
- A combination of methods should be used to aerate.
- Core aerate at least twice a year.
Top dressing involves applying a thin layer of topsoil over an existing turf area.
The purposes of topdressing include:
- Smoothing the playing surface,
- Controlling thatch,
- Promoting recovery from turf injury or disease,
- Changing the soil composition in the rootzone. This is a long term process.
Topdressing is often done in conjunction with aeration, overseeding and matting. Aeration allows new material to work down into the existing root zone, through the aeration holes. Matting, dragging the topdressed areas with a mat drag, helps work the new soil around and into low spots. Overseeding adds seed to the existing turf to encourage thickening of the turf.
Fertilization is the feeding of the turfgrass plant. You can overfeed, as well as underfeed your turf.
Commercially available fertilizers have a nutrient analysis on the label. The first number indicates the percentage of Nitrogen (N); the second Phosphorous (P); the third Potassium (K). A 50# bag of 20-5-10 is 20% nitrogen by weight, or 10lbs. The same bag also contains 5% phosphorous, or 2.5lbs. and 10% potassium or 5lbs.
- Nitrogen promotes healthy growth and good color.
- Phosphorous promotes quicker establishment of new plantings and root growth.
- Potassium promotes root growth, and tolerance to stress from heat, cold, drought and wear.
Generally, most of our athletic turf grasses will respond well to at least 3lbs. of N per 1000 square feet of turf per year. This should be applied in 3 or more applications spaced throughout the year. As a general rule, never apply more than 1lb. of Nitrogen in 1 application.
Key points to remember:
- A soil test is the first step you should take before starting a fertilizer program.
- Your soil pH must be in the proper range 6.0-6.5 for the nutrients in the soil to be available to the turf.
- The analysis of the fertilizer you use should be based on the results you hope to achieve. P & K applications should be based on soil test results. N applications should be based on turf and soil types and the use of the turf.
- Quick release N give a quick green up. Slow release N gives sustained green up. A blend of both is usually a good choice.
- You can over fertilize turf.
- The cost of fertilizer is usually related to its qualities. Slow release costs more than quick release products, but provide more controlled and longer term feeding of the turf.
Overseeding is the process of supplementing existing turf. The seed can be applied in a variety of ways. The most effective method involves use of a mechanical sliver/seeder which “plants” the seed. Other methods of overseeding are (1) to broadcast seed or (2) add seed to topdressing material. The amount of seed used will depend on the condition of the field and the type of grass seed in the seed mix used.
The seed mix may be similar to the existing turf stand on the field or it may be used to introduce a new species.
Before overseeding you should mow 1-2 days in advance. Aerate, topdress if needed, mat drag, fertilize and then overseed. Irrigate as normal after seeding. Ideally activity on the field will be kept to a minimum until the seed has germinated and the new grass has reached a point where it can be mown.
In application it may be impossible to do some of the prep work and after care. Budgets can make it impossible to irrigate, fertilize or topdress. Schedules can make it impossible to keep play off the fields. Overseed anyway!