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