Hot Tub Water and Your Landscaping: Can it Kill Your Grass, Shrubs, or Trees?

Summer is in full swing, which means spending time outdoors enjoying everything nature has to offer… including your hot tub! A spa is a great addition to your backyard oasis and can be a focal point in your landscaping.

If you’ve got a green thumb and are concerned about how your hot tub will impact your lawn and plants, we have answers about how you can have the best of both worlds: a luscious garden and a relaxing spa to use year-round.

Will my hot tub kill my grass, shrubs, and plants? 

With proper planning, most hot tub water can be reused as gray water for watering your lawn, washing your car, or hydrating your home’s foundation (which is particularly useful for arid climates facing drought conditions). The impact of your spa on your landscape will depend on the type of water filtration system you use.

Standard Chlorine Filtration Systems & Landscaping

If you own a hot tub that uses a standard chlorine or bromine-based water filtration system, it will take a little bit of patience but minimal work to be able to safely use the hot tub water on your plants. Plants and grasses do not tolerate chlorine, so you should not use hot tub water on your yard until you’ve addressed the chlorine levels.

Chlorine evaporates from water, and with direct sunlight, can be dissipated from your spa in a matter of days (which is one of the reasons we recommend a spa cover when your spa is not in use!). If you know that you want to drain your spa for regular maintenance and cleaning, you’ll want to refrain from adding any chlorine or other chemicals to the water for at least two days prior. You can either leave the lid open to allow for natural evaporation or run your jets on high for 1-2 hours after that 48-hour period without chemicals.

Once this dechlorination process is finished, you’ll need to test the chlorine levels and wait until they are between 1-4 parts per million (ppm). At this point, the water will be safe for most plants. Gray water should not be used on any plants meant for consumption, such as those in a vegetable garden. 

Spas that use a chlorine system should be drained every 4-6 months or at least twice per year. With a little foresight, you can recycle the water and maximize the cost to you and the environment. If you don’t want to risk the water on your landscaping – even after checking the chlorine levels – you can reuse the water in other ways, such as washing your home, cars, or shed or flushing toilets. 

Salt Water Filtration System & Landscaping

If you own a hot tub from Hot Spring’s Highlife or Limelight collections, your spa is equipped with their FreshWater® Salt Water System. While you can follow the same steps above to remove the chlorine, there will still be some risk to plants from the water’s salt content. Many plants cannot tolerate salt, so it is not recommended to use spa water in your landscaping unless you purposefully design your yard with salt-tolerant plants. 

If water conservation is a concern for you, rest assured that you’re still making a good choice for the environment with your saltwater filtration system. Unlike traditional hot tubs that must be drained every 4-6 months or at least twice per year for safety, your saltwater system will keep your water clean for a year with proper maintenance. That’s far less water that you’ll be pouring down the drain!

Tips for hot tubs and landscaping

A spa transforms your backyard – adding function, fun, and a potential focal point. Here are some of our tips on how you can find harmony between your landscaping and your hot tub:

Use plants to create a natural privacy barrier 

If you live close to your neighbors and want some privacy when using your spa, you can use natural elements to make a fence, such as bamboo, large shrubs, or vines woven into a pergola. Just be aware that plants may drop leaves, bugs, or other natural debris into your spa if you leave it uncovered.

Pick plants that create ambiance

The choice of plants and shrubbery will change the mood you create, and there are many hardy plants that grow well near hot tubs. Look into flowers like marigolds and oleander, fragrant plants like rosemary and aloe, and shrubs like the evergreen euonymus and juniper.

Consider the hardscaping 

To ensure you don’t inadvertently harm your plants, consider having your spa on a patio or deck with enough distance between the splash zone (about a 3-foot radius around your hot tub) and the plants. Container gardens are a popular choice to give you flexibility in distance between your spa and greenery.