Best Ways to Kill Weeds in Rocks

Do you have a rocky or hard landscape that has a problem with pesky weeds and grasses protruding through? If so, the following information may be quite helpful.

We have reviewed some of the most popular weed killers on the market today, identifying the pros and cons associated with each product. We have also included a Weed Killer Buying Guide, which explains everything you need to know when shopping for a weed killer product.

Last update on 2023-01-31 at 14:19 / Affiliate disclaimer / Images via Amazon Product Advertising API

Roundup 5705010 Extended Control Weed and Grass Killer

Made by a company whose name is synonymous with the killing of weeds, this Roundup 5705010 Extended Control Weed and Grass Killer boasts a dual-action formula that not only kills weeds but prevents new weeds from emerging for a period up to four months. Guaranteed to kill weeds to their roots, this product is very effective against weeds in rocky areas, as well as on driveways, patios, sidewalks and along fences and walls.

Within 30 minutes after its application, the Roundup 5705010 Extended Control Weed and Grass Killer is completely rainproof, meaning it will not get washed away; and users will see visible results within six hours.


  • Dual action formula. The dual action formula in the Roundup 5705010 Extended Control Weed and Grass Killer both kills weeds and prevents them from returning.
  • Rainproof. This great combination herbicide will never wash away prematurely.
  • Fast Results. Users of the Roundup 5705010 Extended Control Weed and Grass Killer will see visible results in as little as six hours.


  • Non-selective. This Roundup 5705010 Extended Control Weed and Grass Killer is non-selective, which means it could damage nearby plants.
  • May be dangerous to pets. Users with pests and small children need to be very careful when using this product.

Lontrel Turf and Ornamental Herbicide

Lontrel Turf and Ornamental Herbicide is a selective weed killer that is effective against a wide variety of different weed species, including clover, thistle, dollarweed and groundsel. And while the herbicide will kill weeds on contact, it will not harm any surrounding grassy areas.

Lontrel Turf and Ornamental Herbicide can be used year-round all around your yard and garden without presenting any danger to any wanted plant life. It can be used to provide selective control of broadleaf weeds in new and established landscapes, including rocky areas where it works through the weeds to kill the entire root system.


  • Selective. As a selective weed killer, Lontrel Turf and Ornamental Herbicide will not harm any nearby grass or plant life.
  • Works rapidly. The Lontrel Turf and Ornamental Herbicide is designed to kill weeds on contact.


  • Can damage grass if mixed with compost. Should your compost come into contact with weeds treated with this product it can compromise that compost.
  • Premium-priced. Although effective, Lontrel Turf and Ornamental Herbicide is not a product for the budget conscious.

Bonide 16-Ounce Concentrate Sedge Ender Weed Killer

The Bonide Sedge Ender Weed Killer comes concentrated in a 16-ounce bottle and makes more than enough herbicide to tackle problem weeds and grasses for months. If grass is a problem in your rock garden or desert landscape, this product will not only kill pesky grasses like goose grass, nut grass and all sedges, it will also prevent them from returning. The product is safe to use on and around both Northern and Southern lawns and when mixed properly can cover from 2,000 to 8,700 square feet depending on the mixture.


  • Covers a large area. With the ability to cover up to 8,700 square feet of rocky landscape, the Bonide 16-Ounce Concentrate Sedge Ender Weed Killer is very comprehensive.
  • Pre and Post Emergent. As a pre and post emergent herbicide, this weed killer knocks out problem weeds and grasses and prevents them from returning.


  • Pre-emergent only lasts for a short time. According to some users, the pre-emergent claims of this product are a bit overstated.
  • Needs regular applications. Unlike some products, which may last for months, the Bonide 16-Ounce Concentrate Sedge Ender Weed Killer needs to be applied frequently to be effective.

Weed Killer for Weeds in Rocks: A Buying Guide

When you set out to purchase a weed killer to tackle those pesky weeds and grasses protruding through your rock or desert landscape, there are several things you should definitely consider. Below we have compiled just a few of those considerations to help you buy the perfect product for your needs.

What Are Weed Killers?

Weed killers, also known as herbicides, are important tools for every homeowner and gardener, regardless of ability. Weed killers contain crucial chemicals that help to kill unwanted plants and grasses or inhibit their normal growth. The best weed killer depends on what types of weeds you are trying to eradicate, so it would behoove you to do a little research before diving in with a purchase. Herbicides vary according to their effects – some aim to kill weed seedlings while others seek to kill weeds after they are up and growing between your rocks and desert landscapes.

Why Use Weed Killers?

When weeds are growing in between rocks, many people might choose or be tempted to pull out those weeds manually by hand. However, this can often be a very maddening and time consuming process; and it’s often ineffective. Many weeds and unwanted grasses that are pulled out by hand will come right back up in a couple weeks? Why? Because if you fail to get the entire root out (which is tough when working between rocks), the weed can sprout right back up. Additionally, if a weed is growing in between your rocks it means the environment is right for those weeds to emerge, so even if you do get the entire root, chances are another weed will sprout right back up in its place.

Weed killers can be much more effective against pesky weeds in between rocks. Not only will they kill the plant—root and all—they often keep working long after those weeds have died off. This helps prevent further weeds from sprouting up, and keeps you desert and rocky landscapes looking pristine—as they should.

Knowing the Different Types of Weed Killers

As we mentioned above, weed killers vary according to their effects – some aim to kill weed seedlings while others kill weeds after they are up and growing. The following guide, in which we will introduce you to the four main categories of weed killers, will highlight the different types of weed killers that are currently available and their recommended applications.

Types of Weed Killers

There are essentially four characteristics that describe how ALL herbicides or weed killers work. They include emergence, selectivity, persistence and translocation. In order to select the perfect weed killer for your yard, garden or situation, you will need to understand the absolute importance of each of these characteristics.


When you hear the word emergence as it applies to weed killers, keep in mind that herbicides can be either pre-emergent or post-emergent. Pre-emergent weed killers target germinating weed seedlings before they grow. Post-emergent, as you probably guessed, targets those weeds that have already been sprouted. Therefore, if you notice weeds in your rocks, you should first use a post-emergent weed killer on the leaves of those weeds to kill them. After you have done this, you can then spray a pre-emergent weed killer to ensure they do not return. Pre-emergent weed killers work best in the early spring when most weeds are beginning to germinate.


Weed killers can be either selective or non-selective. Selective weed killers will kill only the weeds, without damaging nearby plants. Non-selective herbicides, on the other hand, will kill everything—all plant life—in the general vicinity.   Hence, if you have plants nearby that you want to protect, you should definitely get a selective weed killer. But for weeds in rocks where there is no nearby plant life, we recommend a non-selective weed killer. Keep in mind that some selective weed killers will NOT kill grasses, so if your weeds are in the form of grasses, only a non-selective weed killer will do.


Persistence is a word in the weed killer industry that describes how long the herbicides will remain active after being applied. Non-persistent weed killers, after application, will do nothing to prevent further growth. On the flip side, persistent herbicides will continue to stop the emergence and prevent future growth of weeds in that area—for a certain amount of time. In other words, no weed killer lasts forever, but a persistent herbicide can keep your rocks weed-free for many months to come.


Translocation is a term that describes how the herbicide works to kill the plants. Herbicides that include the word “translocation” will work their way through a plant’s internal system to break it down. This can take longer, but it is usually more effective. Other weed killers, known as contact herbicides, kill plants on contact, but are not as effective.

How to Deal With Weeds in Rocks Specifically

When working in rocky or desert landscapes, try to fight the urge to pull these weeds by hands. In most cases, this will not be effective (as we explained in the first section of this buying guide).

Instead, to combat weeds that are coming through rocky landscapes, you should use a combination weed killer, one that works as both a post-emergent and pre-emergent herbicide. These combination herbicides are highly effective and will quickly kill weeds growing in hard and rocky landscapes and then deposit chemicals that will prevent new weed growth.

Last Word

When applying any type of weed killer, it helps—but is not totally necessary—that you know what types of weeds are growing there. Often this can help you choose just the right product for you. Now that you know you probably need a combination pre and post emergence product for weeds protruding through your rocks, be sure to read the label about any warnings. Often, these products have chemicals that can be dangerous to small children and pets in the area for a short time after application, so always proceed with the highest degree of caution, and be sure to use gloves and eye protection when handling any herbicide.

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