Ooohhhh, should have read the directions....

I recently read an article on Yahoo about a gentleman that destroyed 40,000 square feet of lawn…. 40,000 square feet! (Depending on where you live, that can be upwards $30,000 or more in sod costs!) He had applied an herbicide that stated that it would also kill grass leaving it unfit for new sod for 6 months.  However, he says that particular information was on page 2 of an 8 page booklet attached to the herbicide. He apparently didn’t read the whole booklet (which is what it is there for) which would have given him basic information, application rates & times, lasting effects and other pertinent information. Chemicals, fertilizers, additives to your landscape are a lot like medicine; you need to read the directions in order to use it effectively! Use these items incorrectly and you could “overdose” your landscape causing harm even death!

I cannot stress how important reading the whole label is! While you may not consider your lawn a weed, the chemical can’t tell that unless it is specifically formulated to NOT damage that particular type of grass. Even then, you may get a temporary discoloration of your lawn or even death if you don’t apply it properly. If you still have questions or concerns, most labels have a helpline you can call for clarity. 

Having said that, I admit sometimes the label can be a bit of a mystery with some of the terms. Here are a few terms you should know:

Non-selective herbicide: Means that it will kill or damage all plant material it comes in contact with! It may say weed killer, but it doesn’t know that you don’t consider your grass a weed.  This is formulated to eliminate most vegetation.

Selective herbicide: Formulated specifically for a particular species or family of plant material. These are made to react to something specific in that particular species, that is unique to it. Even selective herbicides can cause unintentional damage to plants if the spray drifts onto the leaves of a plant you don’t want damaged. If you are using a granular, then be cautious in your distribution. Overthrow with granules can damage plants and you may not have seen the granule land there in the first place. Once it gets watered in, the process has started. 

Pre-emergent: This means it should be applied prior to the particular plant that you want to eradicate showing up. It can be a seed-sterilant that will not allow seeds to germinate.  Note: once a seed starts growing roots, it is no longer a seed and a pre-emergent will not be as effective. It is very important to use this at the proper time, usually noted on the packaging.

Post-emergent: This is for after the plant has either started growing roots or poked its head above ground. It works usually by disrupting some portion of the plant’s nutritional system to kill it. There are some that just outright turn it into a crispy critter (vinegar & salt).

Stinging nettle - leaves are edible when
 steamed

Soil sterilant: This will sterilize the soil completely. This creates a condition where vegetation and often any insects, microbes, beneficial nematodes etc., may not thrive. Some only last a few weeks, some months, some for years! Decades ago it was a common practice to sterilize the soil prior to construction of certain structures and parking lots. The sterilants used could last 50 years or more. If the structure was taken down, the soil was useless for any landscaping unless it was scraped off and replaced.

Toxic: Whether it is toxic to you, to animals, birds, fish, etc., it is a warning that should be heeded! Toxicity can be as mild as a rash or as severe as coma/death. I’m not trying to scare you but the word is used for a reason. Also, contact with the chemical doesn’t mean just with your hands, any part of your skin can absorb a chemical! There are also your eyes, your nose (fumes) and the bottom of your feet.  This is why labels with often tell you to wear shoes, long pants, long sleeved shirts, glasses, etc. Your whole body can conduct the chemical into your system!

Dandelion plant : flowers can be used for wine,
Leaves are edible and roots can be used for
a coffee substitute

If you have an issue with weeds and want to eradicate them, use proactive measures. This can be spending a bit of time once or twice a week pulling what you see; keeping your lawn healthy and not mowing it too low is another way to control weeds. Taller grass can shade the soil, which weeds don’t like and with a healthy root system, it is harder for weeds to establish themselves. When you mow, you will also be removing the flowering portion of the weed which removes its seed making abilities and removing some leaves hinders quite a bit of its photosynthesizing capabilities. This helps kill off the weeds.

Shepard's Purse - a source
of nectar for insects

 Mulching can help in flower beds but you need to layer the mulch at least 3-4 inches for it to be effective. Too little creates a hothouse effect and makes a perfect environment for many weeds. Keep the mulch at least 3-5 inches away from the trunk or stem of any plant. If you don’t you can trap moisture against the stem/trunk and cause it to rot, which in turn can cause disease and/or death of the plant.

There are organic ways to eradicate weeds but you do need to be aware of how they are used and be cautious in applying. For instance vinegar & salt heated together until the salt dissolves then sprayed on the weed is quite effective as a post-emergent control. If you see weeds coming back up, hit them again. It is safe for animals, kids and the wildlife visiting your back yard because it dries quickly and is organic. You may have a smell of vinegar for a couple of hours, but that is less harmful than a chemical.

Common sowthistle - food source for
 beneficial insects

You can use corn gluten as a pre-emergent to sterilize weed seeds in the soil. However, it is a non-selective so it will sterilize any seed in the soil. I recommend this more for established lawns, flower beds, between flagstones, gravel walkways, places where you either have already planted and won’t be adding any seeds to or areas you want to eliminate any seed altogether. Also consider any bulb or corm you plant as a seed unless they have been in the ground long enough to establish roots.

Knowing which type of weed you have can also help you eliminate it. In knowing what you have, you can find out what its needs are and eliminate those. Some weeds like dry, low nutrient soil and some thrive in moist soil. So weed the area then in dry areas water a bit more in that area and add some compost to raise the quality of the soil. In damp or wet soil, see if you can drain it to dry it out some. It may take some time, but changing the composition of the soil can help with weed control. It’s not always foolproof, but it can lead to a better garden.

The type of lawn that you choose can also be a factor in how easy it is to limit weeds. One of the best is St.Augustine. It is hardy, self-repairing and can choke out just about any weed. No it's not the pretty, soft green grass of fairy tales, but in the long run, best for kids, dogs & high traffic. Requires less water & fertilizer once established. It can go dormant in winter, if the temperatures drop low enough.  The softer, greener grasses are beautiful, but also can be very high maintenence. These lawns require more water, more fertilizer, do NOT repair themselves if injured, and are susceptible to more disease than St. Augustine, bermuda and zoysia. These condition can give weeds an upper hand because the grass can stress so easily. They don't always do as well with foot traffic, animals, or sudden temperature changes. This is something to consider when you install a lawn; how much effort you want to put in to maintaining it and what it is being used for. (An injury to a lawn can be from kids running over it continually, dogs racing around, car or bike tires gouges to even mowing a wet lawn & the wheels leave ruts.)

Now, for something one of my professors liked to say “A weed is just a plant growing where you don’t want it to.” This is so true. There is no genus “Weed”, nor a species “Weed.” These plants have botanical names just like the plants you like and want in your garden. Some are beneficial to insects and animals, some are actually have medicinal qualities! They just had the audacity to show up in your yard uninvited!

Happy gardening!

Mary