Is Pre-Emergent Weed Spray Effective in Rock Gardens?

25 Apr '23

A low-maintenance rock garden designed to prevent weed growth.

Keeping your landscape looking pristine can be a daunting task, especially when pesky weeds start popping up in your carefully curated rock beds. 

While pulling weeds by hand may seem like the most straightforward solution, it can be time-consuming and labor-intensive. 

Fortunately, there is a more efficient method: using pre-emergent weed spray.

Rock Garden Challenges


Creating a garden in rocky terrain can present unique challenges for gardeners. The rocky soil can be nutrient-poor, making it difficult for plants to establish and thrive. 

In addition, the uneven terrain can make it challenging to create a cohesive design and require specialized planting tools and techniques.

Drainage can also be an issue, as water may pool in low areas and create stagnant conditions that harm plants. 

Moreover, the rock can be challenging, as it may heat up quickly in the sun, creating a harsh environment for many plants. 

When Should Pre-emergent be Sprayed?

Pre-emergent weed sprays are effective for preventing weed seeds from germinating and taking root in your lawn or garden. 

However, timing is critical when it comes to applying the pre-emergent spray. 

The ideal time to apply pre-emergent is before the weeds germinate, usually in the early spring or fall when soil temperatures reach a consistent 55 degrees Fahrenheit or above. This is typically before the first lawn mowing of the season.

If applied too early, the pre-emergent herbicide may break down before the weeds germinate, rendering it ineffective.

If applied too late, the weeds may have already started to grow, making it more difficult to control them. 

It's important to read the label of the pre-emergent spray carefully and follow the manufacturer's instructions for the best results.

Additionally, weather conditions such as rain or a heavy watering can affect the efficacy of the pre-emergent spray, so it's important to monitor the weather forecast and adjust your application schedule accordingly. 

We can manage the timing and amount of weed spray so you don’t have to worry about it, and our work is guaranteed.

A serene rock garden featuring an array of smooth grey stones arranged in an elegant pattern with green shrubs and flowers.

Does Pre-emergent Work on Existing Weeds?

Pre-emergent weed spray is designed to prevent weed seeds from germinating, but it does not work on existing weeds. 

This means pre-emergent weed spray will not effectively eliminate if you already have broadleaf weeds or other types of weeds growing in your lawn or garden. 

Instead, you'll need a post-emergent herbicide to target and kill the existing weeds. However, pre-emergent weed spray can be an effective tool for preventing future weed growth. 

How to Prevent Weed Growth in Gravel?

Gravel can be an attractive and low-maintenance choice for landscaping but also a magnet for weeds. You can do several things to prevent weeds from sprouting in gravel. 

First, consider using a geotextile fabric as a barrier between the soil and the gravel. This will prevent weed seeds from germinating in the soil and growing through gravel. 

Keep the gravel layer thick enough to help prevent weed seeds from reaching the soil below. 

Maintain the area regularly by removing any weeds that do manage to sprout up. 

Also, consider using a selective herbicide or weed killer for rock garden designed to target only the weeds without harming surrounding plants or the environment. 

Finally, consider planting ground cover plants between gravel borders to provide a natural barrier against weeds.



By applying pre-emergent weed spray at the appropriate time, you can create a barrier that prevents weeds from growing in the first place. 

This can help reduce the number of weeds you must deal with over time, making it easier to maintain a healthy and beautiful lawn or garden.

What our Clients say

I'm busy, detail oriented, cost conscious and highly selective as to whom works in and/or around my home. This is a service based company that actually provides superior service. Don't waste anymore time... call them. ~ a satisfied customer for three years.

Client Charles M., Mesa

I'm so very happy with Custom Weed & Pest Control. I had extremely tenacious weeds, and while they had to come out multiple times to get rid of them, it was covered under my warranty. Now they're gone, and I couldn't be happier.

Client Janice L., Chandler

Your service was phenomenal, and I would recommend you to all my friends.

Client Mike M., Glendale

They did a great job and all my weeds are dying as promised. My backyard no longer looks like a jungle. Thanks

Client Marty G., Cave Creek

Very happy with services. I would like to schedule for both houses this time around.

Client Mike M., Glendale

I was very happy with the service and I would like to setup another appointment.

Client James H., Phoenix

Great people, great results equals great company!

Client Daniel C., Arizona

Free Quote
fast and easy no hassle