Spectracide vs Ortho Weed Killer
Keeping your lawn and garden weed-free can feel like an endless battle. Using an effective weed killer can help you gain control and keep unwanted weeds at bay.
Two popular options for tackling weeds are Spectracide and Ortho weed killers. But which one is right for your needs? Here is an overview of these two weed-killing products to help you decide.
Ortho vs Spectracide Weed Killer
This table of comparison will provide you with a quick understanding of the differences.
Product Info
Spectracide Weed & Grass Killer2 is a non-selective herbicide that will kill any vegetation it contacts. Ortho GroundClear Weed & Grass Killer works on contact, killing any plants and weeds it touches.
Both are intended for use on driveways, walkways, patios, fences, and other hardscapes. Only Ortho specifies use around vegetable gardens.
Active Ingredients
The main difference between Spectracide and Ortho weed killers lies in their active ingredients. While Spectracide contains synthetic chemicals like diquat dibromide, Ortho uses ammonium nonanoate derived from natural fatty acids.
Visible Results
Spectracide states it provides visible results within 3 hours of application. Ortho GroundClear claims to show visible effects even faster in just 15 minutes. So, Ortho may work slightly more quickly.
Rain proofing
An important consideration is how quickly the herbicides become rainproof or water-resistant. Spectracide is rainproof after 15 minutes, giving it quick water resistance. Ortho GroundClear takes slightly longer, requiring two hours of drying time before it becomes rainproof.
Action Mechanism
As a systemic herbicide, Spectracide is absorbed through foliage and moves down to the roots for whole plant control.
Ortho GroundClear works on contact, disrupting cell membranes and burning leaf tissue, leading to a quick burndown of top growth. It does not explicitly claim systemic movement to the roots.
Where to Use
Both Spectracide and Ortho work well on hardscapes like patios, walkways, and driveways. Spectracide does not clearly state it can be used in vegetable gardens.
Ortho is OMRI-listed for organic use and states it can be carefully applied around edible gardens when weeds are actively growing.
OMRI Listing
An important distinction is that Ortho GroundClear carries the OMRI seal, meaning it complies with organic standards for use in organic gardening. Meanwhile, Spectracide Weed & Grass Killer2 does not have organic certification and is not suitable for use around edibles.
When to Apply
For the most effective results, Spectracide should be applied in warm weather above 60°F when weeds are actively growing. Similarly, Ortho advises applying during sunny conditions when weeds grow vigorously to allow thorough contact and absorption.
Where Not to Use
Spectracide clearly states it should not be used on or around edible plants or crops. Ortho also clarifies it should not be applied to desired plants and lawns, as it non-selectively kills any greenery it touches. Neither are suitable for spot spraying lawns.
Frequency of Use
While Ortho says reapplication every 2-3 weeks may be needed for best weed control, Spectracide limits use to just two applications per year, spaced three months apart. So, Ortho likely allows for more frequent application.
When to Replant
After using Spectracide, wait seven days before replanting. With Ortho, you can replant ornamentals after one day but should wait 7 days before replanting edibles, sod, or seed.
Pets Safe
Both herbicides recommend keeping pets away from treated areas until completely dry. However, since Ortho uses fatty acid-derived ammonium nonanoate rather than synthetic chemicals, it may be a slightly safer choice around pets once dried. But always keep pets off treated areas during application and drying.
Our Observation
Based on close analysis, I’m impressed by how Ortho GroundClear seems to edge out Spectracide Weed & Grass Killer2 regarding organic, veggie garden-friendly weed control.
I’m swayed by Ortho’s OMRI certification, proving it complies with organic standards, as well as its natural fatty acid-derived active ingredient that makes it a bit safer around pets. The quick visible effects within 15 minutes also catch my eye.
While Spectracide appears faster-acting overall, those couple minutes don’t make a big difference. For these reasons, I’m inclined to choose Ortho GroundClear as my preferred weed-killer option.
Especially since I grow vegetables and herbs organically at home. I appreciate the rapid, effective, and plant-safe weed control Ortho seems to offer.

James E. Butkovich, Pest control maven with a knack for eco-friendly & Chemical solutions. Blogger with a mission to make homes pest-free, one post at a time.