Tenacity application rates

Tenacity application rates

Simple table to convert Tenacity application rates expressed in fl.oz. per acre to application rates per 1,000 sq ft.

fl.oz/acre fl.oz/1,000 sq ft tsp/1,000 sq ft
1 0.02 0.14
2 0.05 0.28
3 0.07 0.42
4 0.09 0.55
5 0.11 0.69
6 0.14 0.83
7 0.16 0.97
8 0.18 1.11


Battle of the hose-end sprayers : Chapin G362D vs. Ortho Dial N Spray

Battle of the hose-end sprayers : Chapin G362D vs. Ortho Dial N Spray

Spraying herbicides or nutrients using a pump sprayer can be very time consuming , labor intensive,  and getting complete coverage is problematic even when using a marker dye. Hose-end sprayers  – though not appropriate for all situations – can make the task much easier and faster. Two of the most popular hose-end sprayer on the market are the Chapin G362D Professional All Purpose Hose End Sprayer and the Ortho Dial N Spray Multi-Use Hose-End Sprayer. Having used both of them, here are my impressions of these products.

Chapin G362D Professional

The Chapin sprayer , coming in at just under $20 at Lowe’s, is a metal body sprayer that can hold up to 32oz of concentrate. Mixing ratio is adjusted by turning the metering dial at the top, and conversion from teaspoons to tablespoons is done by inserting416dqbdvsgl-_sy450_ a small brass converter into the siphon tube. The sprayer features a removable spray deflector which creates a wide and somewhat coarse spray pattern.

Having used  the Chapin sprayer to spray glyphosate before renovation, I have found that  suffers from a few major issues:

  • In what I’m assuming is an attempt to keep the concentrate bottle vertical, the bottle and nozzle assembly rotates independently from the handle. This makes it impossible to spray at an angle and very difficult to get into hard to reach areas or in situations where you can’t walk on the grass, like after seeding.
  • The sprayer seems to have problems metering out concentrate. After spraying half the yard, I realized that none of the concentrate had been extracted from the bottle. Stopping briefly and then resuming spraying magically resolves the problem, but reliability is an issue.
  • The droplet size created by the deflector is very large, which is less than ideal when doing foliar applications. A finer spray can result in more even coverage and better coating of the grass blade.
  • There is significant space between the bottom of the siphon tube and the bottom of the bottle, which means there will always be a good amount of concentrate left over at the bottom.

Unfortunately, while the build quality appears to be good, the design of the product is flawed. These design issues make its use in lawn care challenging if not outright frustrating.

Ortho Dial N Spray Multi-Use Hose-End Sprayer

The Ortho Dial N Spray, coming in at just under $11, is a hose end sprayer made entirely out of plastic. Like the Chapin, it features41tg2wmb16l a 32oz  concentrate bottle but it is also compatible with large Ortho concentrate bottles – just attach the sprayer directly to the bottle. It features 3 spray patterns : shower, fan and jet. The metering dial is located in the side of the sprayer and features 14 settings.

At first touch sprayer feels cheaply made. It is all plastic and you can actually feel the two sides trying to come apart slightly as you
push the trigger. The concentrate bottle attaches to the body of the sprayer somewhat loosely, adding to the “cheap” feeling. However, upon first use, the Ortho proves to be a good performer. The fan nozzle produces a finer spray than the Chapin, though still more coarse than I would like. The metering is solid – the concentrate gets sucked out evenly and consistently. And since the sprayer body is one piece, you can tilt and spray at an angle. Unfortunately, the shower and jet nozzles don’t seem to have much use in a lawn care setting, though they could come in handy for other tasks.

Bonus: an empty Bayer Fungus Control bottle

687073012705After spraying the contents of a Bayer Fungus Control Ready-To-Spray bottle, I decided to hang on to it to see if it could be re-used. The bottle produces an excellent spray with perfect droplet size, and is a consistent performer. After having re-used it for about 20 applications, varying from fungicide to iron, the thread on the bottle wore off to where it could no longer be re-used. While it lasted, the “free” Bayer bottle was the best performing “hose-end sprayer”.

The winner

Unfortunately, both the Chapin and the Ortho sprayers suffer from flaws. The Chapin, at double the price of the Ortho, is sturdy but unusable due to design flaws. It thus gets a 1 star rating. The Ortho, while not as sturdy, does a good job at half the price and so receives a 3 star rating. Maybe Bayer can turn their RTS bottle into a standalone hose-end sprayer? One can only hope.

Tank mixing order

Tank mixing order

20lknapsack1It is not uncommon for multiple pesticides and fertilizers to be mixed together in the same sprayer tank so they can all be applied in one go. Most pesticides labels provide information on compatibility with other pesticides and fertilizers, but testing of all combinations is impossible. If a substance is not specifically mentioned as compatible, follow the label to perform a compatibility test.

To minimize the risk of active ingredients of different formulations interacting with each other, the following mixing order should be used, from first to last:

  1. Wettable Powders (WP or W)  –  finely ground solids, typically mineral clays, to which an active ingredient is sorbed. They provide an effective way to apply an active ingredient in a water spray that is not readily soluble in water. These dry preparations look like dust, contain a high percent active ingredient (usually 50 percent or more) and are mixed with water for application. Wettable powders form a suspension rather than true solution when added to water. Good agitation (mixing) is needed in the spray tank to maintain the suspension.
  2. Dispersible Granules (WDG)  – manufactured in the same way as wettable powders except that the powder is aggregated into granular particles. They are mixed with water and applied in a spray exactly like a wettable powder. This dry formulation usually contains 70 to 90 percent active ingredient.
  3. Flowable or Aqueous Suspension (F, L or AS)  – very finely ground solid material suspended in a liquid. Liquid flowables usually contain a high concentration (4 pounds or more) of active ingredient and are mixed with water for application.
  4. Emulsifiable Concentrate (E or EC)  – usually contains the active ingredient, one or more petroleum solvents, and an emulsifier that allows the formulation to be mixed with water.  These concentrates are soluble in oil and form an emulsion in water. The emulsion-forming characteristic results from the addition of adjuvants to the herbicide formulation.
  5. Solutions

When using a sprayer:

  • Calibrate the sprayer
  • Read the herbicide label and wear personal protection equipment
  • Fill the tank half way with water, never mix concentrated chemicals in an empty tank
  • Measure chemicals you are adding to the tank.
  • Apply the pesticide according to label directions.
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.


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.

Eliminating Bermuda from your lawn

Eliminating Bermuda from your lawn


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.