Bozeman's Biome: City Chlorine Crashing Summer Flora?

By Franklin Everett Shaw

January 3, 2026

Don’t let your prize-winning petunias in Bozeman wither away because of something you can easily control: chlorine in your tap water. Many residents, especially those in newer subdivisions on the outskirts of town, are unknowingly irrigating their gardens with chlorinated water, slowly poisoning their plants. It’s a silent killer, but with a little knowledge and effort, you can ensure your garden thrives, even with Bozeman’s municipal water supply.

Chlorine, while essential for disinfecting our drinking water, is detrimental to plant health. It disrupts soil microbes, hindering nutrient uptake and ultimately weakening plants, making them susceptible to disease and pests. The problem is exacerbated in Bozeman’s dry summer climate, where evaporation concentrates chlorine in the soil.

First, you need to know what you’re dealing with. Grab a chlorine test kit from a local hardware store like Murdoch’s Ranch & Home Supply or even online. These kits are inexpensive and easy to use. Collect a water sample directly from your outdoor spigot, following the kit’s instructions precisely. Aim to test your water at different times of the day, as chlorine levels can fluctuate. Record your findings. A reading above 0.5 ppm (parts per million) warrants action.

Now, let’s explore some DIY dechlorination methods tailored to Bozeman gardens. For smaller urban gardens, a simple solution is to let your water sit out before using it. Fill a watering can or bucket and let it stand for 24-48 hours. Chlorine, being a gas, will naturally dissipate into the air. This method is effective for small volumes of water, perfect for raised beds or container gardens common in Bozeman’s downtown area.

For larger suburban lawns, a more efficient approach is needed. Consider using a garden hose filter containing activated carbon. These filters attach directly to your hose and remove chlorine as the water passes through. You can find these at most garden centers in Bozeman, such as Evergreen Landscaping. Be sure to choose a filter rated for chlorine removal and replace it regularly according to the manufacturer’s instructions. Neglecting filter replacement renders it useless.

Another option, particularly useful for those with rain barrels, is to add a dechlorinating solution. These solutions, available at pet stores (yes, pet stores!), contain chemicals that neutralize chlorine. They are designed for aquariums but are perfectly safe for plants when used correctly. Follow the dosage instructions carefully, as overuse can harm your plants. This is a great option for residents in areas like Oak Springs, where water conservation is encouraged.

Beyond dechlorination, selecting chlorine-tolerant plants is a smart strategy. Some plants are naturally more resistant to chlorine’s effects. Consider planting these in areas where dechlorination is difficult or impractical.

Here are a few chlorine-tolerant plant options that thrive in Bozeman’s climate (USDA Zone 4b/5a):

• Daylilies (Hemerocallis): These hardy perennials are known for their resilience and come in a wide variety of colors. They are a great choice for adding color to your garden without worrying about chlorine sensitivity.
• Hostas: These shade-loving plants are relatively tolerant of chlorine and add a lush, green texture to your garden. They are perfect for those shady spots under trees or on the north side of your house.
• Russian Sage (Perovskia atriplicifolia): This drought-tolerant perennial is not only beautiful but also quite resistant to chlorine. Its silvery foliage and lavender-blue flowers add a touch of elegance to any garden.
• Yarrow (Achillea millefolium): This hardy perennial is known for its medicinal properties and its ability to tolerate poor soil conditions, including chlorine contamination.
• Marigolds (Tagetes): These cheerful annuals are surprisingly tolerant of chlorine and add a splash of color to your garden throughout the summer.

Soil amendments can also play a crucial role in mitigating chlorine’s effects. Adding organic matter to your soil, such as compost or well-rotted manure, improves its structure and drainage, helping to leach out chlorine. Organic matter also provides a habitat for beneficial soil microbes, which can help break down chlorine and other harmful chemicals.

Consider using a soil amendment like peat moss or composted bark. These materials improve water retention and drainage, creating a healthier environment for your plants. You can find these at local nurseries like Town & Country Supply Association.

Another helpful amendment is mycorrhizal fungi. These beneficial fungi form a symbiotic relationship with plant roots, helping them absorb nutrients and water more efficiently. They also help protect plants from stress, including chlorine toxicity. You can purchase mycorrhizal fungi inoculants at most garden centers and apply them when planting or transplanting.

A common mistake Bozeman gardeners make is assuming that all plants are created equal. Some plants are simply more sensitive to chlorine than others. Tomatoes, for example, are particularly susceptible to chlorine damage, exhibiting symptoms like leaf burn and stunted growth. If you’re growing tomatoes, be extra diligent about dechlorination or consider growing them in containers with dechlorinated water.

Another pitfall is overwatering. While it may seem counterintuitive, overwatering can actually exacerbate chlorine toxicity. When the soil is constantly saturated, chlorine accumulates, increasing its concentration and its harmful effects. Water your plants deeply but infrequently, allowing the soil to dry out slightly between waterings.

Finally, don’t forget to monitor your plants for signs of chlorine damage. These signs include:

• Leaf burn: Brown or yellow edges on leaves.
• Stunted growth: Plants that are smaller than expected.
• Yellowing leaves: A general yellowing of the foliage.
• Poor flowering or fruiting: Reduced flower production or small, underdeveloped fruits.

If you notice any of these symptoms, take immediate action to reduce chlorine exposure and improve soil health.

Protecting your Bozeman garden from chlorine damage requires a multi-pronged approach. Test your water, dechlorinate when necessary, choose chlorine-tolerant plants, and amend your soil with organic matter. By following these steps, you can ensure that your garden thrives, even with the challenges of chlorinated water. Don’t let chlorine steal your harvest; take control and cultivate a healthy, vibrant garden in the heart of Montana.