Safe, Organic Solutions To Herbicides & Preventive Strategies For Invasives

Introduction

Herbicide and insecticide used in backyards and public squares are a major problem for butterfly preservation, as well as wildlife ecosystems as a whole, since invertebrates are the bottom of the food chain that supports life. Loss of habitat is immense across the US and a growing movement to combat this is to add as much of that habitat back as possible through wildlife gardening on private properties. This creates stepping stones of safe places for pollinators in between larger natural environments. However, this conservation goal can be smothered when neighbors and surrounding properties are regularly sprayed with various round-ups, which can even cause drift into your own yard. Nearly all commercial round-ups bought in stores are based with harmful chemicals that not only destroy biodiversity, but pollute your soil. The active ingredient in most of these herbicides/insecticides is glyphosate. Glyphosate is the most popular herbicide in New Jersey agriculture, as well as in our own backyards, and it is only increasing in popularity. It is awful for your health, with continuous exposures having been linked to greater cancer risk, oxidative stress in the body, severe allergies, and all kinds of other unwanted health concerns. The goal of this blog post is to provide an alternative to glyphosate not only for our own health and pollinator conservation, but to make gardening easier for you.

Tactics:

Mulch - having a single, thick mulch job can stop weeds from growing up in your garden for sometimes up to a few years without much work (but for some yards should be applied annually). It also does not prevent your native perennials from spreading. 

Hand pulling - this should always be your main occupation for keeping up with your gardens. It is also necessary before trying many alternative herbicide tactics and solutions when there are pre-existing invasives on your property. 

Perennial smothering - This is probably my favorite form of combating invasive plants because it works so well. A lot of our native perennials grow taller and denser than introduced plants, which allows the opportunity for “smothering” your invasives as you pull them. Essentially the idea is to replace each invasive with a native plant. Over time, as you remove larger and larger sections of your invasives, it will stay that way if you plant multitudes of preferred natives in bunches together (but it is best to integrate species when planting natives, although it is okay to have sections of just one native. Keep in mind that you want to create an ecosystem with wildlife gardening, rather than creating a display). If you remove invasives from areas of your yard and leave the open space, they will return. However, by adding in plant life to outcompete it with your aid, they will slowly disappear. By native perennials growing taller and denser than introduced plants, it deprives the ground space for invasives to grow and deprives them of light. Plants such as goldenrods, ironweed, joe-pye-weed, common and swamp milkweeds, thoroughworts, native sunflowers, golden alexander, beardtongues, etc. are all great for this. 

Growing out your lawn - it is not only healthier for your lawn and grass to let it grow a bit higher than most people keep their yards, but it also greatly reduces the amount of weeds by letting the grass grow denser and filling in exposed soil. There are also all sorts of native perennials and good weeds that could have expanded from your gardens and have been routinely trying to sprout up. By limiting your mowing, you may be able to yield some surprise bonus plants that you didn’t know were there. 

Salt hay or straw during the winter - this is a great way to prevent cold tolerant invasives like mugwort and English ivy from getting worse over the winter. These plants take advantage of warm winter days to spread across open ground and take over new areas of your garden. By adding a two-inch layer of salt hay or straw, it will help prevent this from happening. 

Irrigation - by irrigating your gardens where you have native plantings, it reduces watering exposed top soils where introduced plants will germinate and can dehydrate invasives during droughts.  

Organic solutions: 

*It is important to note that overuse of some of these solutions in one spot can change the pH of your soil, as things like vinegar are acidic, so they can lower pH levels, but work well and are safe when they are applied more selectively to the plants. Knowing your soil pH levels can be important, as different plants like different pH types, and even good properties like nitrogen, if too rich in some places, can cause an overabundance of grasses (this is why cornmeal isn’t always recommended as a weed killer). 

Vinegar - can be very effective. It is non-selective, so it will take out any greenery (so be careful around your natives), but it is generally not always super efficient on grasses. You can even buy organic horticultural kinds with diluted, 20% acetic acids. 

Sprinkling salt - rock salt or table salt can be used to fight against sprouting weeds early in the spring and can act as a grass barrier on garden, or lawn edges. 

Essential oils - there are various different kinds of organic essential oils that can be used to attack sprouts and young weeds that you can look up and decide what may be best for you and your price range. Essential oils can be an expensive alternative to herbicides, but are great because they’re volatile and environmentally, very safe. They stunt seed germination and cause tissue damage to plants by causing enzyme changes and cell death. 

Common Backyard Invasives In South Jersey To Look Out For: 

English ivy

Porcelain berry 

Autumn clematis 

“Vinca” or periwinkle 

Mugwort 

Oriental bittersweet 

Japanese honeysuckle 

Hairy vetch 

Wild mulberry 

Asiatic dayflower 

Prickly sow thistle 

Chicory 

Japanese spindle tree 

Crabgrass 

Multiflora rose 

Japanese knotweed 

Various asian pears - bradford pear 

Tree of heaven 

Persian silk tree 

Unsure of what these plants look like, or whether you have them? Use iNaturalist to help ID your plants and look up pictures. This is a free website, or app that uses an AI algorithm to identify your pictures of plants, fungi, and wildlife.

- Jack McDonough

Coordinator

NABA South Jersey Chapter