Overseeding fescue lawns

Overseeding fescue lawns

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Tall fescue is one of the most popular turf grasses in the transition zone due to its ability to form a great looking lawn, while exhibiting better heat and drought resistance than other cool season grasses. However, unlike other grasses like Kentucky Bluegrass, tall fescue does not spread on its own. Overseeding is a great way to make up for summer losses and increase lawn density in fescue lawns. It is also a great way to introduce new cultivars into your existing genetic base, which can help with disease resistance.

If your existing lawn has 50% or less coverage, you may want to consider a complete renovation instead.

What is overseeding?

Overseeding is the process of spreading seed “on top” of your existing lawn to increase density. As with all seeding projects, success depends upon 3 factors:

1. Seed to soil contact

In order for grass to successfully establish, the seed must be in direct contact with the soil so that the roots may grow into the soil and extract nutrients. Seed that sits on top of thatch or dead grass has a poor chance of establishment.

2. Heat

Fescue seed germinate best when temperatures outside hover between 78-85 degrees. Within this range, fescue germination will take place in 4-5 days. At temperatures in the low 70s/high 60s, fescue germination may take up to 2 weeks.

3. Water

After seed has been applied and watered, it must be kept continuously moist until germination. Allowing the seed to dry can result in a complete loss. Fescue seed must be watered 3-4 times a day for 15 minutes at a time for the first 7 days. The goal is to keep the seed moist, not to soak the soil. After the first week, the frequency of watering should be gradually reduced and the quantity of water applied at each watering gradually increased.

When should lawns be overseeded?

Fescue lawns North of the Mason-Dixon line should be overseeded mid-August. Fescue lawns in the transition zone should be overseeded around Labor Day. This timing gives the new grass the time it needs to establish so it can survive the following summer.

Spring is a very bad time to overseed lawns due to weed pressure and the limited time available to the grass to establish before the summer heat. Seeding projects in the spring generally result in a weedy mess and wasted time and money.

Preparing for overseeding

Having everything ready when the time comes can make the difference between success and failure. You will need:

  • The square footage of your lawn. Tools such as this can be of great help.
  • Seed. Fescue should be overseeded with 4-5 lbs of seed per thousand square feet as determined above.
  • If you do not have an irrigation system, you will need hoses, a multi-zone controller and impact sprinklers.
  • A broadcast spreader.
  • Starter fertilizer
  • A push mower. If you have a riding mower, it may be too rough to use on the new seedlings.

Overseeding the lawn

  1. scalped

    In order to give the new seed the best chance to establish, the existing grass must be cut as low as possible. At the same time, since we don’t want to kill the existing grass, this process must take place gradually. Beginning two weeks before your target seeding date, start mowing your grass every 3-4 days lowering your cutting height each time. The final cut should take place on the day of seeding at your mower’s lowest cut setting.

  2. Remove all clipping from the lawn. Use a rake to remove as much of the thatch and dead grass as possible. Remember, we need good seed to soil contact.
  3. seedUsing the broadcast spreader, spread the seed at a rate of 4-5 lbs per thousand square feet slightly overlapping each pass. Do not over-apply – grass that is planted too dense is unable to develop properly and looks like doll hair.
  4. Using the broadcast spreader, apply the starter fertilizer at the rate indicated on the bag.
  5. You are now ready to water. Program your controller to water each zone 3-4 times a day for 15 minutes.(No sprinkler system? A Orbit 4 zone watering system may come in handy)

Fescue germination should take place in 4-5 days and the seed should be kept moist throughout the process. Mow the grass 14 days after seeding date and maintain the lawn at 3.5″ throughout fall to encourage lateral growth.

With a refreshed, thick lawn, the  grass will always be greener on your side.

Controlling broadleaf weeds in cool season lawns

Controlling broadleaf weeds in cool season lawns

While a good pre-emergent program will keep most annual weeds out of your lawn, perennial broadleaf weeds like dandelions, white clover and buttonweed will be unaffected and will need to be removed using a selective post-emergent herbicide.

dandelion-2b

Post-emergent herbicides come in a variety of forms.  Weed and feed type products are the worst choice, because:

  • The timing for fertilization and weed control is never the same.
  • It must be applied to the entire lawn whether there’s weeds or not to avoid differences in color caused by some areas being fertilized and some not
  • The granules have to stick to the weed making them ineffective.

For these reasons we will skip over weed and feed  products and talk about standalone liquid and granular herbicides. Most contain the same active ingredients:

  • 3-way herbicides contain 2,4D, mecoprop and dicamba. These herbicides will control a very large number of broadleaf weeds like dandelions and clover. They are cheap and very effective, making them an excellent first choice when dealing with broadleaf weeds. Examples are Ortho Weed-B-Gon and Trimec.

When spraying broadleaf herbicides, the following rules should be observed:

  • Always read the label and follow all instructions exactly to avoid damage to your lawn.
  • If you only have a few weeds in your lawn simply spot spray rather than applying to the entire lawn.
  • Apply just enough to wet the leaf.
  • Do not apply to lawns which are stressed, damage may occur.
  • Do not apply to new turfgrass seedlings until after the grass has been mowed at least three times.

Herbicides are most effective when weed are actively growing – a dormant weed will not absorb the herbicide. A dose of fertilizer followed by a few days of watering can help bring the weed out of dormancy, at which point it can be sprayed. Adjuvants such as an non-ionic surfactant  greatly increase the effectiveness of your herbicide application by breaking water surface tension and helping the spray droplets stick to the leaf instead of beading up and rolling off. Even under ideal conditions, repeat applications every 10 days may be needed for some stubborn weeds like ground ivy.

Mulching leaves on your lawn

Mulching leaves on your lawn

 

Note : the article below was written by fellow lawn care enthusiast MorpheusPA and is being reproduced here with his permission. Head on over to his blog for more great tips on lawn and garden care : The Green, Green Grass of Home

So what do leaves do? They raise the organic matter percentage in the soil, provide fall food for your worms and micro-arthropods living in your soil, encourage bacterial and fungal activity in the soil, and mulch the soil for winter. Lawns that have been leaf mulched will retain their green color further into winter, green up faster in spring, and generally show greater health than lawns that receive no mulching.

1-24MulchLeaves2REBECCAHow much should you use? Close to 300 pounds per thousand square feet disappears into the grass in a few days if well-chopped, but applications certainly do not have to be made at that rate. This study shows the results of mulching 150 to 450 pounds of leaves into the soil, and effects are generally excellent.

But isn’t leaf litter ugly? Well, yes. The above study states that leaf litter at the highest application resulted in leaves still left on the lawn in spring. However, if you have a rotary mower it becomes easy to render the leaves invisible. With the very large amount I’m using, I mow slowly four times over the area to reduce the leaves to bits smaller than the nail on my pinky (and I have small hands!) By the time I complete the task, almost no visible litter remains–99% has fallen into the grass and becomes invisible. The remaining 1% disappears with the next rainfall.

What’s the NPK ratio of leaves? About 0.8-0.35-0.2 according to this source, but don’t worry about it. Trees extract almost all the chlorophyll and nitrogen and place it in root storage for the winter. Since there is a small amount of phosphorus in the leaves, mulching them is better than allowing rainwater to percolate through them while they sit on the street as the phosphorus enters the waterways and causes algae blooms that aren’t good for lakes and streams. The reason leaves are mulched isn’t to feed the lawn but instead to provide additional organic material for the soil.

Isn’t it more work?  No, not unless you import leaves.  It’s far easier and faster to mulch the leaves your trees drop into the lawn than it is to rake and discard them.

How much at once?  To avoid smothering your lawn, try not to chop up more than about an inch of leaf litter at a time.  That may mean mowing a bit more often under your trees, but the results are worth it!

Foliar Iron Application

Foliar Iron Application

Note : the article below was written by fellow lawn care enthusiast MorpheusPA and is being reproduced here with his permission. Head on over to his blog for more great tips on lawn and garden care : The Green, Green Grass of Home

Iron applications help with the lawn color, but generally do little for the soil.  They’re always optional, but if you find your lawn color is more yellow than you like, they will help restore color.

There are three methods–bottled iron products from any big box store, ferrous sulfate, and ferrous ammonium sulfate.  This article discusses all three below.

Warning:  Iron should never be applied if the temperature will exceed 85 within the next 24 hours.  If the weather takes you by surprise, irrigate the grass enough to wash the iron off of the leaves.  Failing to do so may risk a burn.

Bottled Iron Products:

Almost every big box and local gardening store will carry pre-mixed bottles of iron.  Often, the iron is listed as “chelated,” or bound to an organic molecule to preserve it against chemical reaction.  While this isn’t important when the product is on the leaves, it will help the grass continue to absorb the iron after the product has been watered in.

Most bottled iron products contain 3% to 6% iron by weight, although there are certainly exceptions.  Check the label to make certain that the product’s price is reasonable for the amount of iron it contains.

Simply follow the label instructions and observe all warnings about temperature of application.  If the temperature limit of usage is not listed, assume it shouldn’t be used if temperatures exceed 85.

Most of the chelates used aren’t effective at higher pH levels, so there isn’t much sense in paying for the chelation if your pH is much over 7.2.

These products are readily available, pre-mixed, and sometimes come in their own spray containers.  The down-side is that they tend to be much more expensive than home-made options.  They’re a great initial test to see if your lawn will respond well to iron, and a good option even after that for people who don’t wish to mix their own.

Ferrous Sulfate:

Ferrous Sulphate

The name sounds a bit scary, but it’s just iron sulfate, or iron bound to sulfur and oxygen. Ferrous sulfate (technically, ferrous sulfate heptahydrate, or including 7 molecules of water attached to the ferrous sulfate) is 15% elemental iron by weight, or one of the higher amounts of iron easily available to homeowners and safe for lawns.

Ferrous sulfate, or iron sulfate, is often available in small quantities at gardening stores in the Bonide brand, and the quality is excellent. Larger quantities can be purchased online.

For elite bluegrasses, 4 ounces of ferrous sulfate per thousand square feet diluted in a minimum of 1 gallon of water seems to be the best amount to use.  For non-elite bluegrasses, any amount up to and including 4 ounces of ferrous sulfate in 1 gallon of water per thousand square feet seems best.  For fescues and ryegrasses, 2 ounces per thousand in 1 gallon of water per thousand square feet maximum would be the limit.  Overapplication will result in very dark grass.  In the case of fescues and ryegrasses, it can turn an unnatural almost black-gray-green color that’s fairly unattractive.  The grass is healthy, and will eventually regain normal coloration, but this can take several weeks to months.

Mix externally in a bucket and pour the solution into the sprayer, leaving any undissolved ferrous sulfate and foreign material behind.  This will reduce clogging considerably.

Mix the above amount of ferrous sulfate plus a small amount of any surfactant into 1 gallon of water.  For a surfactant, you can use a quarter to half an ounce of baby shampoo or inexpensive adult shampoo, dish soap (non anti-bacterial), or Morpheus Soil Conditioner.

Again, never spray the lawn if the temperature will exceed 85 degrees within 24 hours.  If you discover that the weather has changed and the temperature is now too warm, irrigate the lawn immediately to wash the mix off the leaves and into the soil.

Discard any unused solution appropriately as it doesn’t store well and will rapidly turn to rust.  Make certain to clean your sprayer afterward, including running water through the wand, to avoid clogs.

Ferrous Ammonium Sulfate:

Ammonium Sulphate
Ammonium Sulphate

This name sounds a bit scarier than ferrous sulfate!  However, it’s simply iron and ammonia bound to a sulfate.  Although it contains less iron by weight than ferrous sulfate, the mix is home-made and will contain the same amount of elemental iron as the ferrous sulfate you put into it.  Consequently, if you used 4 ounces of ferrous sulfate, you’ve applied 0.60 ounces of elemental iron.

So why use it?  The darkening from ferrous ammonium sulfate exceeds that of ferrous sulfate.  Ferrous ammonium sulfate is a somewhat more stable solution as well, being less likely to turn to rust before the grass can absorb it. Ammonium sulfate contains 21% nitrogen, supplying the nitrogen needed to generate chlorophyll (the green color) in plants.

Making ferrous ammonium sulfate requires two chemicals:  ferrous sulfate and ammonium sulfate.

Ferrous sulfate, or iron sulfate, is often available in small quantities at gardening stores in the Bonide brand, and the quality is excellent. Larger quantities can be purchased online.

Ammonium sulfate is often not available at local stores, but can be purchased online from The Organic Store.  The link is to the main fertilizer section, so you will need to scan down to find ammonium sulfate.

For elite bluegrasses, 4 ounces of ferrous sulfate per thousand square feet diluted in a minimum of 1 gallon of water seems to be the best amount to use.  For non-elite bluegrasses, any amount up to and including 4 ounces of ferrous sulfate in 1 gallon of water per thousand square feet seems best.  For fescues and ryegrasses, 2 ounces per thousand in 1 gallon of water per thousand square feet maximum would be the limit.  Overapplication will result in very dark grass.  In the case of fescues and ryegrasses, it can turn an unnatural almost black-gray-green color that’s fairly unattractive.  The grass is healthy, and will eventually regain normal coloration, but this can take several weeks to months.

To create ferrous ammonium sulfate, take the amount you chose above and multiply by 0.85.  Add that much ammonium sulfate to the mix.

So for several mixing levels:

Ferrous sulfate amount: Ammonium sulfate amount:
1.0 oz 0.85 oz
2.0 oz 1.70 oz
3.0 oz 2.55 oz
4.0 oz 3.40 oz

 

…and so on, always using 0.85 ounces of ammonium sulfate for each ounce of ferrous sulfate you use.

What happens if you make a slight mistake?  Nothing, really.  Using too much ferrous sulfate is no issue at all, you’re simply applying a mixed solution of ferrous sulfate and ferrous ammonium sulfate.

Using too much ammonium sulfate is not much greater of an issue.  Although ammonium sulfate can strip a bit of calcium from the plant, a minor imbalance in the amount used won’t cause any problems.  Some fertilizers use ammonium sulfate as their primary nitrogen source and work well without damaging the grass.

Mix externally in a bucket and pour the solution into the sprayer, leaving any undissolved ferrous sulfate, ammonium sulfate, and foreign material behind.  This will reduce clogging considerably.  When adding it to your sprayer, use a small amount of any surfactant into 1 gallon of water.  For a surfactant, you can use a quarter to half an ounce of baby shampoo or inexpensive adult shampoo, dish soap (non anti-bacterial), or Morpheus Soil Conditioner.

For this chemical, spraying above 80 degrees is not recommended as it has a higher probability to cause burning.

If you discover that the weather has changed and the temperature is now too warm, irrigate the lawn immediately to wash the mix off the leaves and into the soil.

Discard any unused solution appropriately as it doesn’t store well and will rapidly turn to rust–although more stable, it will still transform over a day or so.  Make certain to clean your sprayer afterward, including running water through the wand, to avoid clogs.

Soil Conditioner and Kelp Help Plus Humates

Soil Conditioner and Kelp Help Plus Humates

Note : the article below was written by fellow lawn care enthusiast MorpheusPA and is being reproduced here with his permission. Head on over to his blog for more great tips on lawn and garden care : The Green, Green Grass of Home

Soil conditioner will, over a period of use, loosen soils and increase water and air penetration.  Combined with the Kelp Help plus Humates (and/or organic feeding), the soil organisms further open the soil and help maintain it in its looser, healthier condition.

Soil conditioners work by increasing flocculation (gathering together) of soil particles, increasing the amount of space between soil particles for water and air to penetrate.  The kelp and humic acid work into these new pores with the water and encourage the growth of bacteria and fungi, which further flocculate your soil and help keep it separated.  Combined with organic feedings, the influx of food further increases the bacterial and fungal populations, improving your soil and increasing the health of your lawn and gardens.

The Formulae:

 

Morpheus Kelp Help

4 ounces kelp extract

8 ounces humic acid extract

2 gallons water (from the tap)

Optional:  A small dash of molasses (unsulphured blackstrap molasses, available at the grocery store)

 

Morpheus Soil Conditioner

80 ounces sodium laureth sulfate

8 ounces yucca extract

40 ounces water (from the tap)

 

How to Use:

Mix each in a separate container (you may double or half the recipe if your container is larger or smaller).

Apply both at 2 ounces each per thousand square feet of lawn or garden area in a backpack, hand-held, or hose-end sprayer.  Any dilution over 2 ounces per gallon is perfect, so you don’t need to worry that your hose-end sprayer is watering down the mix too much.

For example, if you apply only the Kelp Help, 2 ounces of the solution you created would be placed in your sprayer and sprayed over 1,000 square feet.  If you apply only the Soil Conditioner, the mix is identical.

If you apply both at once, use 2 ounces of the Kelp Help and 2 ounces of the Soil Conditioner in your sprayer and spray over 1,000 square feet.

For very poor soils, applying every 2 weeks will work the fastest.  Once the soil begins to improve, once a month or once every three months is fine.

Once the soil is where you want it, application once or twice a season will help maintain the soil in its current condition.

Watering your lawn

Watering your lawn

sprinkler

Proper watering is the most important lawn care practice upon which healthy lawns are built. And a healthy lawn is a great looking lawn. Grasses, like all other plants, require water to stay alive.  Mother Nature provides for a good portion of your lawn’s water needs, but during periods of hot weather or drought, supplemental water is needed in the form of irrigation. The way in which this water is provided will guarantee the success or failure of your lawn.

A lot of homeowners – especially those with an irrigation system –  have been conditioned to water for 20-30 minutes multiple times a week. This creates a vicious circle in which because water is always available at the surface, the roots grow shallow to take advantage of this water. Because the roots grow shallow, water must be provided frequently or the plant suffers. Frequent watering also causes numerous fungal disease problems which typically wipe out large portions of lawns in early summer. But there’s a better way – it’s called deep an infrequent.

Deep and infrequent watering is a simple concept which involves applying larger amounts of water which penetrate deeper into the soil only when the grass shows signs of drought stress. Water penetrates heavier soils like clay very slowly, while others soils like sand drain very quickly. Temperatures vary from season to season. Some areas of your lawn get full sun, while others are in shade. Some grasses need more water than other. All these variables mean that water needs vary from region to region, and even from one section of your lawn to the next. The deep and infrequent method presented below accounts for all these variables by watering to a depth of 6 inches only when your grass needs it. Sound complicated? It’s not, here are the 2 golden rules:

  • Do not water unless your grass is showing signs of drought stress. This means that you may only need to water once a month in the spring, or not at all in the fall. This accounts for all weather and lawn condition – if the lawn is stressed it’s time to water, be it every 3 days in the summer or once a month in the fall.
  • When watering, water until a 6″ flat head screwdriver easily penetrates the soil all the way to the handle. This will ensure that regardless of soil type and sprinkler output, water penetrates deep enough to encourage deep root growth.

What are the benefits of a deep and infrequent watering program?

  • Grasses are encouraged to “seek” water deeper in the soil building a deeper root system which will better sustain them through periods of drought.
  • Allowing the surface of the soil to dry between watering means that weeds will be unable to compete with your grass.
  • A lawn that is not constantly damp is far less susceptible to fungal disease.
  • Deep and infrequent uses less water resulting in money savings.

Ready to jump on board? Great. Keep in mind that if you’re making the switch, the transition will have to made slowly to allow your grass to adapt to the new regime. Once you master proper watering, the grass will always be greener on your side – especially when everyone else’s lawns are crisp from the heat or dead from fungal disease.

Eliminating Bermuda from your lawn

Eliminating Bermuda from your lawn

bermuda

For folks in warmer climates, enhanced varieties of Bermuda are one of the main grasses used in home lawns. For those of us with cool season lawns, Bermuda is the weed from hell that you can’t even kill with fire. You pull it, you spray it with glyphosate, and it just comes back stronger like it thrives on taking a beating. Pre-emergents (see here) are effective in stopping Bermuda seed , but what about Bermuda which has already take a foothold?

Fortunately, there are options. In recent tests, a mix of fluazifop-p-butil(Fusilade II) and triclopyr (Turflon Ester) provided 70% control of post-emergent Bermudagrass in Tall Fescue turf with little injury to fescue when applied at label rates. This gives lawniacs south of the Mason-Dixon line a great option for Bermuda post-emergent control, although complete eradication may take a couple of seasons. With Bermuda under control in your lawn while it devours your neighbor’s lawns summer after summer, the grass will always be greener on your side.

University of Tennessee – Bermudagrass Control in Tall Fescue and Zoysiagrass Turf

NCSU – Bermudagrass Control in Tall Fescue

Conquering crabgrass and annual weeds

Conquering crabgrass and annual weeds

Crabgrass is an annual weed which invades lawns all over the country every summer. No matter how thick your lawn, crabgrass always seems to able to rear its ugly head. A lot of homeowners are trapped in what seems to be a never ending cycle : you spray it, some of it dies, some of it powers through, and the following year the problem is worse.

crabgrass-1100Effective control of annual weeds like crabgrass is only possible if the seed cycle is broken. Pre-emergent herbicides are designed to do just that: prevent the seed from turning into a viable plant. Pre-emergents work by creating a shallow “barrier” in the soil that the germinating plant must go through to reach the surface. It is important to realize that pre-emergent herbicides do not prevent the seed from germinating, they kill the germinating plant thus depleting the seed bank.

There are various pre-emergent herbicides available to homeowners, many of which can be found at your local home improvement stores. Two of the most popular (and effective) pre-emergent herbicides are dithiopyr and prodiamine. Proper application of either will provide nearly 100% control of most annual weeds, including crabgrass. Prodiamine has the advantage that it does not leach and does not begin to break down until the soil warms up, which means it can be applied early in the season and provides long lasting control (up to 8 months with one application). For this reason, it is my pre-emergent of choice.

The effectiveness of pre-emergents is highly dependent upon timing and proper application. Observing the following rules guarantees success and a weed free lawn for the year:

  • Prodiamine-65-WDG-5-lbs-2Since pre-emergents do not affect plants which are already established, the pre-emergent barrier must be in place before the seed germinates. Pre-emergent must be applied when soil temeperatures reach 50 degrees @ 4″, or when forsythia plants bloom.
  • Even and complete coverage is crucial. Missing spots during application will cause “holes” in your barrier where weeds can germinate and produce more seed for the following year. A good backpack sprayer will help you get good coverage with minimal effort, but for smaller lawns even a 2 gallon pump sprayer will do the job.
  • Most pre-emergents require watering in within a short period of time. Applying before a rain means Mother Nature can do that part for you, or you can irrigate immediately after application per label requirements.
  • More is not better. Applying too high a rate can cause damage to your existing grass roots and also extend the pre-emergent into your overseeding window (if applicable), meaning none of your grass seed will grow.
  • Avoid applying pre-emergent during periods when your lawn is stressed. It can make things worse.
  • Follow all instructions on the product label and maximum yearly application rates.

A good pre-emergent plan is the foundation of any great lawn. It guarantees a weed free lawn and helps your grass thrive. Master it, and the grass will always be greener on your side.

Are organic fertilizers worth it?

Are organic fertilizers worth it?

Recently the popularity of organic fertilizers has been on the rise. More and more people use cracked corn, alfalfa or soy bean meal as their main source of nutrients for their lawn.  Proponents of organic fertilizers often claim that the use of organic fertilizers brings has great benefits. Let’s analyze each claim:

  • Hard to overdose vs. synthetic. This is true. While application instructions on fertilizer bags are generally clear and easy to follow, some novices may feel more at ease knowing they can’t really over-apply and hurt the lawn. Synthetic fertilizers are fairly forgiving as well though, I have applied synthetic fertilizer at double the rate with no ill effects except to my back from all the extra mowing.
  • Slow release. This is also true. Organic fertilizers have to be broken down by bacteria before nutrients becomes available to the plant, resulting in a slow trickle of nitrogen.  However, synthetic options such as coated urea and UMAXX exists at a cost up to 7 times lower per pound of nitrogen.
  • Feeds the soil microbes. This is true, but the need for an over-inflated microbial population in the soil beyond what grass clippings and bugs and normal natural processes can sustain is unclear.
  • Increases organic matter/improves soil structure. This claim is false. Studies have shown little to no long term contribution to soil organic matter content from materials applied on the surface. In pastures studies have shown grass roots to be the major contributor to organic matter – up to 80%. Other studies have show shoot restitution programs to have zero or negative effects of soil organic matter.
  • Safer for kids and dogs. This claim is also false, both are equally safe. No child is going to pick granules of fertilizer out of lawn, and if they did, it’s unclear which one would be worse, a granule of urea or a piece of rotting corn coated in bacteria and fungus.

Organic fertilizers do come with some clear disadvantages over synthetic fertilizers:

  • Cost. Organic fertilizer is up to 11 times more expensive per pound of nitrogen than urea and up to 7 times more expensive per pound of nitrogen that coated urea.
  • Cumbersome. It takes 13-20 pounds of organic material per thousand square feet vs 2 pounds of urea per thousand square feet to apply one pound of elemental nitrogen. That can literally add up to truckloads of corn per year for larger lawns.
  • Slow to act. Since the organic matter has to be broken down by bacteria and fungi before nutrients become available to the plant, it takes a while before you see any results, generally 3-4 weeks.
  • Unpredictable. No one can say for sure when the nitrogen is going to be available to the plant. Availability of nitrogen also changes with temperature since bacterial activity slows once it gets cooler.
  • Unsustainable. Plant derived organic fertilizers are the equivalent of using a gas engine to power a generator which is then used to release hydrogen from water through electrolysis which is then burnt to power a car via steam. Also, a lot more carbon is spewed into the atmosphere for the production and delivery of 20 pounds of corn than for the equivalent 2 pounds of urea.

So with very little benefit backed by mostly anecdotal evidence and a lot of disadvantages, what place does organic fertilizer have in the average lawn? There are situations where organic fertilizers are needed, such as fertilizing an area where nitrogen runoff must be avoided. For most homeowners, synthetic fertilizers work faster, are less work to apply and are significantly less expensive than organic fertilizer. Give your grass the nutrients it needs and the grass will always be greener on your side.