Grubex Spreader Settings Guide

Grubex is an insecticide and soil treatment product manufactured by The Scotts Company LLC, the company famously known for its Scotts lawn spreaders. Grubex also acts as a preventive formula for protecting your lawn against grubs and other bugs.

Suppose you’ve been having issues with pests or insects on the lawn, and you’ve been taking steps to try to solve it yourself without outsourcing to a lawn dresser. In that case, the chances are that you’ve been recommended to try Grubex, as it’s a popular solution to insect problems across the US.

While that’s the case, using Grubex effectively will require its spreader settings – which also depends on the type of spreader you’re using for the application. More so, without the correct setting, you will likely not get a positive result after every application.

grubex spreader settings

 Grubex Spreader Settings for Spreaders

The table below gives the standard spreader settings for spreading Scotts Grubex with all types of Scotts spreaders. While that’s the case, understand that these settings only directly apply to Scotts’ Grubex and not ‘Grub Gone’ by Green Earth or ‘Grub Control’ by Bayer – which are similar insect prevention and control products. Also, the ideal quantity to use is 1bs/1000 sq. ft.

Spreader Settings
Scotts Drop Spreaders  5 1/2
Scotts Broadcast Spreaders 3 1/2
Scotts Wizz Spreader 3 3/4
Scotts Elite Spreader 3 1/2

If you have a different spreader from Scotts’ and don’t think about getting a new Scott spreader soon, we’ve got you covered.  We’ve done some tests to develop standard settings for different spreaders popularly used across the US.

Grubex Spreader Settings for Broadcast Spreaders

Model Setting  Distance Between Passes (ft.)
Vigoro Rotary (#SB4000V) 4.5 3
Vigoro Rotary (#SB3000RD) 3. 2.5
Earthway EV-N-Spread Rotary 13 3
Cyclone Rotary 5.25 6
K-Gro Rotary 4 5.5
Ortho Rotary 4 5.5
Precision Rotary (#SB50) 5.5 5
Sears Rotary 4 5
Red Devil Rotary 3 2
Republic EZ Rotary (#540) 4 5
Quaker Rotary 5.5 5
STA-Green Rotary (#85500, #45-02291) 5.5 5


Grubex Spreader Settings for Drop Spreaders

Model Settings
Central Drop 5
K-Gro Drop 8
Ortho Drop 8
Precision Drop 3
Quaker Drop 4
Red Devil Drop 3
Republic EZ Drop 8
Sears Drop 8
STA-Green Drop 3
Vigoro Drop (#DS4000V, DS4500RD) 3

At any rate, understand that these spreader settings are merely starting points, you may still need to try them out on a testing ground first before applying to your entire lawn. Also, ensure the testing ground you use is less than ¼ of the entire lawn.

Bugs that Grubex can Control

  • White grubs (including larvae of):
  • Japanese beetle
  • Asiatic garden beetles
  • Aphodius spp
  • European chafers
  • Green June beetles
  • May/June beetles
  • Northern masked chafers
  • Oriental beetles
  • Southern masked chafers
  • Caterpillars
  • Armyworms
  • Cutworms
  • Sod webworms
  • Annual bluegrass weevils
  • Billbug grub
  • Crane-fly larvae
  • Chinch bugs

How and When to Apply Scotts Grubex

Aside from the usual guidelines like making sure  you’re using a suitable spreader setting or making sure you clean the spreader after use, it’s important to know that Grubex should only be applied to dry lawns.

If you must water first, allow the lawn to dry (it usually takes 2 to 5 days) before applying grub. This is because you will also need to water down after application – you want to prevent any unnecessary cause of erosion.

While that’s the case, you should only apply Grubex once a year, and it should be done from spring to early summer. Application during this period kills grubs waking from winter hibernation and also kills newly hatched grubs in the soil – beetles lay their eggs in the summer.

Can I Use Grubex with Fertilizer?

Guidelines on the Scotts product page advise that only straight fertilizers can be used at the same time with Grubex. Straight fertilizers primarily supply one nutrient – nitrogen, phosphorus, or potassium.

Meanwhile, there’s no guideline for mixing Grubex with straight fertilizers, so it is best to apply them one at a time, giving at least a two-week gap between applications.

How to Use Grubex with Children or Pets in the Home

After-application procedures are often simple when living alone. Most of the time, you only need to wash your hands, clean the spreader and clear the pavement you used for measurement. However, things can get tricky when you have children or pets in the house.

First, you want to ensure they avoid the lawn or the areas where you applied the insecticide until it’s dry. More so, you want to pay attention to notice any spillage on driveways or sidewalks and wash them in as well.


  • Danny Saunders

    Danny Saunders is a tech enthusiast. He enjoys getting his hands dirty with the features and settings of tech products and pushing them to their limits just to know how to get the best from them and how well they can endure "abuse" without breaking down. He shares his findings on this blog.