Should You Use a Pump Sprayer to Water Plants?

At first glance, a garden sprayer might seem like a handy solution for watering your plants, especially for hard-to-reach spots or small berms where hauling out the hose feels like overkill. But here’s the reality: just because you can use it doesn’t mean you should—at least not without understanding the potential risks and limitations.

So, can you use a garden sprayer to water plants? The short answer is yes, although there are some very important factors to consider. First, there is the obvious: a sprayer that has been used to apply herbicide poses a threat to your plants, even if it has been rinsed out. Second, even with a clean sprayer, will it spray enough water to be effective?

If you are still on the fence, read on to discover what I learned when I tried using my sprayer to water plants.

Chemical Residue – The Hidden Danger

If you have a brand new sprayer that’s never seen chemicals, it can certainly be used safely to water plants. However, if you are asking the question, it is likely because you are repurposing an old sprayer that has previously held a herbicide. So, will a solid rinse make it safe for watering your plants?

If done correctly, thoroughly cleaning your sprayer should allow you to use it for watering. However, even after a rinse, tiny traces of herbicide might still be present, and that’s all it takes to damage or kill sensitive plants.

Putting this Idea to the Test

I’ve had first-hand experience using a sprayer with Roundup, then thinking I had the sprayer cleaned out enough to go and spray a herbicide safe for my lawn. Unfortunately, there was some residual Roundup left behind, and I ended up with dead patches of grass.

This experience makes me cautious about doing anything like watering flowers or other plants. But when I decided to write about this topic, I thought I would test it out. I had recently used my backpack sprayer to apply Roundup, so it was the perfect opportunity.

After finishing the spraying I had to do around the farm, I rinsed the sprayer out a couple of times. I followed the pretty standard method for thoroughly rinsing a sprayer. Then I filled it with water and picked out an unfortunate tulip to serve as my guinea pig.

The Results

Surprisingly, after a few days, the tulip was doing just fine. In comparison, the grass and other weeds that I sprayed before cleaning the sprayer were long dead. So technically, it worked out fine in this one instance. Although it is not something I would risk on my wife’s entire flower bed

If you were set on using a sprayer that has had herbicide in it, then at least minimize the risk by using a specialized tank cleaner during one of the rinse cycles. Products like Blazer, or even a diluted ammonia solution, can help neutralize and break down chemical residues that water alone can’t tackle.

But even with the best cleaning process, there’s still no 100% guarantee, especially when dealing with herbicides. That’s why many seasoned gardeners and landscapers play it safe and keep a dedicated sprayer for different tasks. Like a dedicated Roundup sprayer or one just for fertilizers. Having a separate, clean unit can save you from a whole lot of regret later.

So, is it worth the risk? If your sprayer has ever held herbicide and you care about your plants, the safest answer is: don’t use it for watering. Either invest in a new sprayer or reserve your old one strictly for chemical applications.

Nozzle Size & Spray Pattern Issues

Even if your sprayer is brand new and completely free of chemical residue, there’s still another problem that makes it less-than-ideal for watering: the nozzle.

A typical spray nozzle on a garden sprayer will deliver a low-volume mist in a flat fan or cone pattern. Some will be in a more solid stream, but none of these options provides you with effective watering. If you only wish to spritz some small plants, then perhaps a low-volume cone nozzle would work well. However, you won’t get enough volume to quench the thirst of larger plants, flowers, or shrubs in the heat of the summer.

*On the left, you can see the low volume mist from a garden sprayer nozzle compared to the images on the right of a hose-end sprayer and a traditional watering can.*

If you look at the tools that are actually designed for watering: watering cans, hose end nozzles, etc. They all offer large spouts or shower head patterns that produce some serious flow. With your garden sprayer, the restricted flow rate takes forever to get enough water to the roots, especially in larger beds or containers.

What Kind of Nozzle Is Needed to Water Plants

Now, if you’re committed to using a sprayer, there may be an effective workaround: you can swap out the nozzle for a larger one. There are many different types of sprayer nozzles, and they come in different sizes and spray patterns. A large capacity cone nozzle would be the best option for larger plants and shrubs. As I mentioned earlier, if you are caring for smaller plants and delicate flowers, then maybe the fine mist from your sprayer is enough.

When Using a Sprayer Might Make Sense

Now that I have made the argument against watering with a sprayer, I have to admit, there are a few specific situations where it can come in handy, as long as it’s a clean, chemical-free sprayer dedicated solely to water.

Here are a few use cases where a sprayer might actually work well:

Watering hanging baskets or hard-to-reach planters: If you’ve got containers tucked high up or in tight corners, a handheld or backpack sprayer gives you the reach without dragging around a hose or lifting a heavy watering can up in the air.
Light misting for humidity-loving plants: For ferns, orchids, or seedlings that benefit from humidity, a sprayer equipped with a misting nozzle can be an effective way to increase moisture around the plant without soaking the soil.
Spot-watering in small gardens or greenhouses: If you’re only dealing with a few pots or raised beds, a clean sprayer can be a quick grab-and-go option—just don’t expect high volume.

If You Still Want to Use a Sprayer – Do It Right

Still thinking about using a sprayer to water your plants? It can be done—but only if you take the right precautions. A little preparation goes a long way in making sure you don’t accidentally turn a watering session into a plant-killing disaster.

Here’s how to do it safely and effectively:

✅ Start With a New, Chemical-Free Sprayer

If the sprayer has ever held herbicides, use it at your own risk. It’s best that you just consider it unsafe for watering. If you do, be sure to rinse it out thoroughly with a tank cleaner.

🔄 Swap Out the Nozzle

Most garden sprayers come with low-volume nozzles with spray patterns that produce fine droplets at high pressures aimed at coating the plant surface, not soaking the soil with high volumes. To avoid blasting your plants or applying water too slowly, swap to a high-flow adjustable stream nozzle. Keep the pressure on the lower side. In other words, don’t over-pump the handle

Suggested Nozzles for Watering: TeeJet Adjustable Cone Nozzle – (works with any spray gun that has an 11/16 thread on the spray wand extension. Learn more here.)

If you just want to mist plant foliage, then the small nozzles will work, but if your sprayer has a flat fan nozzle or a solid stream, switch it to a cone pattern.

🏷️ Clearly Label the Sprayer

Once you dedicate a sprayer to watering, label it clearly. This prevents any future mix-ups that could lead to cross-contamination. A permanent marker or weatherproof label works well—just make it obvious.

Using a sprayer for watering isn’t ideal, but if you’re set on it, doing it the right way makes all the difference. Treat your watering sprayer like a dedicated tool, and you’ll avoid the most common mistakes that lead to plant damage.