Gardening myths and actual options: Extension agent explains

Ariel Whitely-Noll
| Special on the Capital Journal

As the gardening season hits its peak, many homeowners are looking for simple, quick solutions to pests and problems that crop up in the garden. Many of the customers who call our horticultural hotline have tried unsuccessfully to solve the problems at home.

With so many problems cropping up in the landscape, are these women’s stories or social media tricks actually working?

Homemade weed killer

The myth

Various recipes containing Epsom salts, dish soap, vinegar and other household products have been circulating on social media as “safe” weed killers throughout the spring. This remedy is as dangerous as it is fertile.

Epsom salt initially consists of magnesium and sulfate and is often used as a fertilizer. As a fertilizer, this product can actually help plants grow – including weeds. You can apply so much salt that it will negatively affect the weeds, but this method has two major drawbacks. First, you need a lot of salt and the cost would be significantly higher than buying a traditional weed product. The second and most important drawback is that this amount of salt – enough to kill weeds – poisons your soil for other plants and soil life.

Garden vinegar is a product that is used as a herbicide in organic farming. This is not the same product that you buy at a grocery store. This product can be dangerous to handle and is often labeled for agricultural use. Using a low concentration, like grocery store vinegar, can cause the top of the weed to wither and wilt, but is ineffective for complete weed control.

Dish soap can be more difficult to determine how exactly it will affect plants. The main reason it is hard to tell what it will do is because dish soap is a broad term meant to describe many products, none of which have an intended purpose that involves plants. Many plants have a waxy layer over their leaves and stems to protect them from pests and diseases.

Applying soaps can remove this protective layer and expose plants to external threats. This could help with weed removal, but has not been shown to be effective. Antibacterial soaps could also have a negative impact on friendly soil microbes that our coveted plants rely on.

The most important thing to keep in mind with such recipes is that none of these products are designed for this purpose. Mixing products, even things you think are safe, can be dangerous. Read the product labels and follow their instructions.

The solution

If chemicals aren’t your thing, there are alternative methods. Most non-chemical weed control methods require planning and manual labor. Cultivating soil while planting can help clear existing weeds in your garden, but it can also produce previously buried weed seeds. Don’t waste time after growing or planting – remove weed barriers and mulch immediately.

Weeds, layers of newspaper or cardboard can help prevent weeds. Add a healthy layer of compost or mulch on top to hold moisture and remove weeds. If you do not refuse to use store-bought products, apply a pre-emergence product under the barrier and mulch. This product prevents seeds from germinating, so only use it in areas where you will be planting established plants, not where you are starting seeds.

Once weeds appear in your yard, pulling and digging is a chemical-free, albeit sometimes difficult, way of controlling weeds. Some weeds, like bindweed and walnut, multiply every time you pull them up, so make sure what you’re dealing with before you start pulling.

Deadly soil

The myth

We get many calls from local residents who believe that there is a pathogen or chemical in their soil that will kill all of their plants. While both could become a reality, this is almost never the case. Unless you are aware of a chemical that has been added to your soil, it is unlikely that your soil has been contaminated.

Lead soils are a very serious problem in urban areas, but that’s because they are dangerous to people. If you think you may be contaminated with lead, the Kansas State University laboratory will run tests for this and other metals.

Chemicals are difficult to test in soil and most laboratories do not offer this service. When customers think their soil is the culprit, the real reason their crops are stressed isn’t nearly as interesting – it’s often the weather. Extreme drought, heat, cold or the extremely wet spring that we had this year, all stress plants, sometimes to the point of death.

The solution

Since the gardeners are unable to control the weather, they are forced to cope with what is given to us. As with any gardening problem, a well-chosen, planted and cared for plant can withstand a lot more stress than a weak plant. For our cold hardiness zone (6A), choose plants that can withstand our extreme heat. Place the plants where they want to be. Plants in full sun that are planted in partial shade may never have the same vigor as if they had been planted in a suitable location.

Water can be a much more difficult element in combat. When we don’t have enough, deliver it – not just to your flowers and vegetables, but also to trees and shrubs. When we have too much, the options are more limited. Too much water makes us all wish we had introduced more organic matter into the soil (improved drainage) or created a rain garden or a dry stream bed. Now is the time to make these adjustments. Build your healthy floors and look for problem areas that collect water or drain onto the street. Work on redirecting it to where it’s needed and creating a space for abundance.

Just spray it on

The myth

This is my least loved myth. So many homeowners see a problem in their landscape and start spraying without knowing the exact problem. It sounds silly to say, but spraying random chemicals actually doesn’t work. A fungicide for an insect problem won’t work. A pesticide on a plant that is stressed by weather conditions will not work. Spraying the right thing at the wrong time … it doesn’t work.

The solution

There are so many great ways to find out what’s wrong with your plants. My personal favorite is our Shawnee County Extension Master Gardener Response Line. This free service uses trained volunteers and expansion resources to find practical solutions to your gardening problems. Call, email, ask questions online, or drop by. If a chemical solution is part of the recommendation for your problem, make sure it is the right product, at the right time, and in the right way. Follow the label and be patient.

Ariel Whitely-Noll is the horticultural agent for Shawnee County Research and Extension. She can be reached at arielw@ksu.edu.

Shawnee County Extension Master Gardener Response Line

Address: 1740 SW Western Ave., Topeka, KS 66604

Phone: 785-232-0062, ext. 105

Email: sn@listserv.ksu.edu

Website: www.shawnee.k-state.edu/lawn-garden/garden-response-line.html