How to Control Spring Weeds in the Kentucky Lawn

Welcome to the Sunshine Gardening Podcast, where we explore everything related to gardening to assist you in creating the garden of your dreams. I'm Kristin Hildabrand, your host. In today's episode, episode 25, we'll discuss a topic that every homeowner thinks about as spring approaches: weed control on the lawn. We will speak with an expert and UK Extension Associate in Turfgrass, Kenneth Clayton, about common spring lawn weeds found in Kentucky, pre-emergent herbicides and how they work, and the optimal timing to control grassy weeds effectively. We will also recommend helpful resources to help control spring weeds on Kentucky lawns. So, grab your gardening gloves and favorite beverage, and let's learn how to transform your yard into the envy of the neighborhood. Let's get started! Episode 25 Information: Several homeowners come into the office asking questions about weed control for Kentucky lawns during the spring. What weeds are in the lawn in the spring? Can you give some examples? (starts at 2:12) What control measures are best for those weeds during the spring? (starts at 5:15) Can you explain pre-emergent herbicides? How do they work? (starts at 7:03) Can you explain the timing and when to apply those pre-emergent herbicides? Does the forsythia shrub in bloom help with the application? (starts at 8:53) What are some common examples of pre-emergence herbicides for lawns? Where can we purchase them? (starts at 12:21) Is there a good resource to recommend using pre-emergent herbicides for the lawn? Preemergence Herbicides Cooperative Extension Service for Kentucky Lawns: AGR-272: Preemergence Herbicides for Kentucky Lawns (uky.edu) Identification and Control of Henbit and Purple Deadnettle: AGR-226: Identification and Control of the Very Similar Winter Weeds Henbit and Purple Deadnettle (uky.edu Weed Control for Kentucky Home Lawns: AGR-208: Weed Control for Kentucky Home Lawns (uky.edu) Get ready because Kenneth Clayton is returning in the next episode to share all the dos and don'ts for spring lawn care in Kentucky! Keep an eye out for this exciting segment in the future! That concludes another episode of the Sunshine Gardening Podcast! We hope you enjoyed learning about spring weed control and gained valuable insights to help you tackle those pesky invaders in your Kentucky lawn. A big shout-out to our guest, Kenneth Clayton, for joining us today! To access the show notes for episode 25, please visit our blog at warrencountyagriculture.com! Before we wrap up, please subscribe to our podcast for more gardening wisdom, tips, and inspiration delivered straight to your ears. If you have any questions, feedback, or topics you'd like us to cover in future episodes, please don't hesitate to contact us. As always, we wish you happy gardening, and may your spring be filled with vibrant blooms, lush lawns, and the satisfying feeling of nurturing nature right in your backyard. Until next time, this is Kristin Hildabrand signing off. Keep growing, thriving, and listening to the Sunshine Gardening Podcast! The Sunshine Gardening Podcast The Sunshine Gardening podcast covers research-based information from the University of Kentucky Cooperative Extension Service to help inspire and encourage gardeners in the Kentucky garden and landscape. Kristin Hildabrand, Warren County Extension Agent for Horticulture, shines the light on various gardening topics, from fruit and vegetable production, gardening techniques, care and maintenance tips, pests, insects, and more to help the sun shine brighter over the Kentucky garden! To stay updated on upcoming episodes, make sure to follow on Apple Podcasts, Google Podcasts, and Spotify. This way, you'll get notified as soon as new episodes are released. ★★★★★ Very helpful! I’m in Oldham county starting my first (very ambitious) garden. Such great tips here.

Episode Transcript

(00:00):
Welcome to the Sunshine Gardening podcast where we
explore everything related to gardening to assist you
in creating the garden of your dreams.
I'm Kristen Hildebrand, your host. In today's episode,
episode 25,
we'll discuss a topic that every homeowner thinks
about as spring approaches.

(00:21):
That's weed control in the Kentucky lawn.
We will speak with an expert and UK
Extension associate in turfgrass,
Kenneth Clayton,
about common spring lawn weeds found in Kentucky,
pre emergent herbicides and how they work,
and the optimal time to controlling those grassy

(00:42):
weeds effectively.
Lastly, we will also provide helpful resources
to help control spring weeds in the home
lawn.
So grab your gardening gloves and favorite beverage,
and let's learn how to transform your lawn
into the envy of the neighborhood.
Let's get started.
Welcome to the Sunshine Gardening podcast.

(01:04):
This gardening show will equip and inspire avid
gardeners with tips and tricks to help them
navigate the gardening world. The show will also
highlight specific growing requirements for seasonal plants so
the sun will shine brighter over their Kentucky
garden.
And now, here's that ray of sunshine,
garden enthusiast and horticulture

(01:24):
extension agent, Kristen Hildebrand,
with the University of Kentucky Cooperative Extension Service.
Alright. Today on the podcast, we're excited to
have with us is Kenneth Clayton. How are
you today, Kenneth? I'm doing well, Kristin. How
about yourself? I'm doing so good. And it
seems like the reason I'm doing so good
is that spring is definitely in the air.

(01:46):
And with the arrival of spring, it seems
like we always get a ton of questions,
people coming into the office about weed control,
and it always relates to their home lawn.
And I was hoping that you could talk
to us a little bit more today about
spring weeds that are in the Kentucky lawn,
and kinda tell us a little bit more

(02:06):
information about what those spring weeds are and
give us some basic examples of those.
Yeah, absolutely. Kristen, I know today it is
February 26th. We're recording this and it is
supposed to be 70 degrees in Lexington here.
So we're thinking about the spring weeds. And
when we think about
spring weeds control and what's out there in

(02:28):
the lawn right now,
we're really kind of,
at our second best time of the year
to treat the weeds. The fall is when
we can get a hang of those at
the best time, but the spring, we're gonna
see a lot of those winter annual weeds.
So when we think about weeds, it's important
to know what the weeds are as well
as the life cycle of those weeds. So

(02:50):
we're a lot of what we're seeing right
now are our broadleaf weeds, which are things
like our common chickweed,
our henbits,
and our purple deadnettles.
Those are the things we're gonna see flower
first in the spring, but also in our
lawns that aren't quite growing quickly.
We do have perennial lilies such as our
wild garlics and our wild onions

(03:12):
that you can see up right now. So
those are the main weeds. Also perennial broadleaves
like our dandelions.
I believe I've seen dandelions flower about 12
months out of the year somewhere
here in the state of Kentucky.
So those are the main weeds that we're
going to see in our lawn right now.
A little bit later in the year, around

(03:32):
May, June, depending on the weather, we'll start
to see some of our
summer annuals, such as our crabgrass and our
goosegrass germinate.
I really like that you had a general
overview of what we can see, especially like
you mentioned,
their winter annuals. And it seems like when
you're driving down the road,

(03:52):
especially in the fields too, you'll see that
bright purple
bloom,
and you say, oh, it's so pretty, but
then you find out it's either pinbit or
purple dead nettle. And a lot of people
wanna get rid of it. And that's leads
us into this next question I have, but
what control measures are generally best for these
weeds during the spring? Because like you mentioned,
for winter annuals, they germinate

(04:12):
generally in the fall of the year. Is
that correct?
Yes, that's correct. So these have germinated in
the fall, and they typically overwinter as a
small rosette, and then they're the first thing
to flower in the spring. So fall
weed control, you can get them when they're
small. You can actually use pre emergents in
the fall as well to stop several of

(04:34):
these weeds. But at this point, if you
have them, you wanna try to get them
on a day when it's
warm above 55 degrees and sunny,
but earlier rather than later.
If you wait too late into the season,
you wanna consider your options about if you're
spraying herbicides
on, you know, things like purple dead nettle

(04:54):
and Inbit, They are winter annuals, so they
will
and die on their own as the temperatures
increase.
So if you wanna get good control of
them, the best time to do that is
before you get that flush of flowers, when
they're putting all of their energy into flowering.
I mean, hit them while they're small. And
typically,
three way herbicide,

(05:15):
something with 24D,
an MCPA,
and a dicamba.
There are tons of products available,
but that's gonna do much better than just
using a 24 d alone
on these. I mean, especially this time of
year, you wanna use a three way herbicide.
And that'll also be effective on your wild

(05:35):
garlic, onions,
and dandelions
as well. That's good to know, especially for
the wild garlic and because I know a
lot of people, you know, as soon as
they make their first mowing for the season
in the spring, they they really do get
a good width of that. Yes. With the
with those weeds that you mentioned there as
far as the control, is it helpful to
try to do a little bit of a

(05:56):
spring mowing and then hit it, or is
it better just to
wait and, like you said, just use the
three way herbicide?
Once you spray that, you don't wanna mow
it off right away. So you wanna give
it a couple days to work into the
plant before mowing. So that that's the only
real
considerations
when when mowing in the spring and spraying

(06:16):
the herbicides.
Now is it true that you need to
have a little bit of moisture in the
ground before you spray a herbicide if you
do look towards a three way herbicide?
Yes, absolutely.
Coming off this past fall where we had
significant drought, and I believe it was just
a couple of weeks ago that all of
the state of Kentucky
came out of some

(06:38):
moderate drought with the rains that we've had.
But if you are in a situation where
the soil is extremely dry, you wanna time
those applications when the plant is growing, to
actively take up the herbicide.
Yes. And of course, we always mention,
follow that label really closely since it's the
law. And I know earlier on, you mentioned,

(07:01):
pre emergent herbicides.
Can you explain that? Just define what pre
emergent herbicide means.
Yes. So pre emergent herbicides
are herbicides
that we need to apply
before the weeds emerge,
so it's in the name of it. If
we apply those after the weeds emerge, we

(07:22):
are not gonna get control of the weeds.
So pre emergent herbicides
are predominantly
used for summer annual grasses, but we need
to think about a spring
application timing on those. Pre emergent herbicides need
to be applied
and either irrigate it or have rain on
them to activate the herbicide to push it

(07:43):
down into the soil, and so what that
does is it doesn't prevent the germination
of the seeds,
but it prevents the emergence
of those grassy weeds. So when the seed
germinates,
it sends out that first root, the radical,
and it comes in contact with that herbicide,
and it'll prevent it from growing leaves and

(08:03):
prevents
cell division and prevents the growth of of
the plant. So that's important
timing
and preemergence. If it is emerged, we need
to think about postemergence
herbicides at that point.
Yes. And I'm glad that you're talking about
pre emergent herbicides
because, you know, like, we always get some

(08:24):
questions. And depending on what the weather looks
like for us in the spring,
it can be kind of hard to time
those particular
sprays when they're needed. Like, I've kind of
always heard the rule that you can use
the bursythia bloom, which is a bright yellow
bloom. It's the one of the earliest ones
that comes into bloom in the Kentucky landscape.

(08:46):
But is that a good indicator plant to
use or do you have other recommendations
on the timing of those preemergence?
Yes. Yeah. That's a great question, Kristen. So
and being in Kentucky,
we are in the transition zone. We're having
spring right now in February.
I'm seeing daffodils blooming, crocuses have been out

(09:06):
for a couple weeks.
And depending on where you are in the
state, Western Kentucky can be a little bit
ahead of Lexington and Eastern Kentucky. So that
timing can be very difficult to figure out
with pre emergent herbicides.
I would say
it's always better to
on the side of being early
with those pre emergent herbicides because again,

(09:28):
if you apply them after the weed has
already emerged,
you're basically wasting your money there. And so
the forsythia
is a good indicator plant.
Typically, we're looking at forsythia when it has
the gold blooms on it first thing in
the spring, and we want to get that
pre emergent out about the time that it's
half gold or half green. Beyond that, we

(09:50):
may be pushing a little bit on our
timing window there. But with that being said
is an indicator, it's not a perfect indicator,
especially as we see different varieties and cultivars
of forsythias.
We can see wide variance in the bloom
times of those. I mean, even, you know,
one side of a house to the other
side of the house, can be, you know,

(10:12):
a week's difference in forsythia bloom.
So if you'd see gold forsythia blooming, definitely
have getting that pre emergence out in your
head. But I prefer,
if possible, to go by soil temperature.
And the Kentucky Mesonet website
has several weather stations across the state that

(10:32):
can get you really close to your county,
to your home, and I like to look
at an average
2 inch soil temperature
between 5055
degrees Fahrenheit
for a 5 day average.
So that's not taking a soil thermometer and
going out at 2 in the afternoon and
it was 55 one day, but then the

(10:54):
next 3 days, it's, you know, a high
of, of 45 degrees. That's not the indicator.
We wanna look at a 5 day average
on that consecutively
at the 2 inches.
And that's where the Mesonet can really get
you close to that timing for for your
location.
Yes. We just had, Shane Hollandy
just, you know, as episode before this one,

(11:15):
come on and talk about the Kentucky Mesonet
site. And it's really interesting. You can, you
know, even download their app and have it
on your phone to be able to check
that out depending on where you're located. So
I appreciate you mentioning that. So 2 inches
down
or at least 50 to 55 for 5
day average. Is that what I caught?
Yes. That's correct. And in the show notes,

(11:37):
we have a publication
called pre emergent herbicides for Kentucky lawns,
and that covers the soil temperatures as well
as the indicator for Cynthia plants, so you
can take a look back at that. Yeah.
Now I know that there's a lot of
preemergent
type products out available
in the market, and it could be different

(11:59):
for rural areas to more urban type areas.
But where what kind of active ingredients are
we looking for in pre emergent
herbicides there, if you don't care to elaborate
more on that? And I don't know if
you have a good place to purchase, but
could you tell us kinda where you typically
might go for your area?
Yeah. Absolutely. The 3 most common pre emergent

(12:23):
herbicide
active ingredients
are
dithiopyr,
pendamethalin,
and prodiamine.
These are also included in that publication
so you don't have to figure out how
to spell those,
But
the dithiopyr
is a little bit unique in those in
that it actually will have some activity

(12:45):
on 1 to 2 leaf stage crabgrass,
but this is extremely
small crabgrass that is hard to see unless
you're down on hands and knees looking at
it. So if you're later in the year,
that's definitely what I would recommend is the
dithiopyr.
The pendimethalin is an older chemistry versus the
prodiamine,
but the key to this is there are

(13:07):
dozens and dozens of products available
in your big box stores, in your garden
centers, and there is a lot of marketing
on the front of the bags, very little
information about what's actually in that. So be
sure to turn those bags over when you're
buying your pre emergent herbicides
and look at the active ingredient in there.
Dathiopyr, like I said, is often gonna give

(13:29):
you the widest
time frame and and range to get that
down So you can apply that a little
bit later than the others. Often, the pendamethalin
will be your cheapest product, and that's what
I've seen. But that's just because it's an
older chemistry.
So be aware of that, and when you're
looking at those. And another thing to mention
with the pre emergent herbicides is that because

(13:51):
we are in Kentucky and we can get
warm early and then we can have winter
come again and then summer again, I recommend
doing split applications of your pre emergent herbicides
and you can put that down early when
the soil temperatures first start to warm up
and figure out the total
application amount that you would need for the

(14:11):
season and split that in half. So you
make that first one around forsythia,
yellow blooms, 55 degree soil temperatures,
and then you can come in another
approximately
6 weeks later
and make that second application.
And often with the preemergence being on fertilizers,
that allows you to not put such a

(14:32):
big amount of nitrogen and push growth too
much at once, and it also extends the
life of that preemergence in the soil. So
things like crabgrass will germinate much earlier than
goosegrass.
And so we'll often see a lot of
goosegrass issues at the tail end of the
season.
But if you're applying all of your pre
emergent in early March, that's asking a lot

(14:53):
of that product to get all the way
through September.
So if I don't wanna split application, you
get an extended life and a little bit
better control that way. I appreciate that tip
on the split application, especially to give you
longer lasting control because those grasses are mean,
I feel like, you know, for the home
lawn, and everybody kinda wants that lush and

(15:15):
dense looking
lawn as well. Is there any other tips
that we should know about with applying pre
emergent herbicides that we haven't already talked about?
I know you talked about, you know, temperature,
moisture,
and the different products, but is there any
other helpful tips that you would provide?
Yeah. Again, just making sure that when you
apply those,
that you irrigate afterwards

(15:37):
or that there's timely rainfall.
We don't want that product to sit out
there for 2 weeks with no rain or
irrigation
to work it down into the soil. It
needs to be activated and in the soil
before the germination of those seeds. So that's
an important aspect of the preemergence there. You
can either spray these products or apply them

(15:57):
granularly.
As far as preemergence
go,
either one is sufficient, and usually
the pre emergents that are sparged onto a
granular pro with fertilizer
is the most commonly available,
and that's fine to use those for pre
emergents.
Other things as far as
spring weed control, not necessarily preemergence,

(16:20):
but it's also to keep an eye on
our nuts edges.
These are something that we want to treat
earlier rather than later. So it can be
end of April,
1st May, we start to see some of
our nuts edges come up, and those are
gonna be much easier to treat when they're
small. And when you see them sticking up
above the lawn and going to seed, you're

(16:41):
gonna have a much more difficult time controlling
those. And then also indicator for pre emergences,
look around driveways,
roadsides,
sidewalks,
anywhere where you have bare ground and it's
just a little bit warmer because of that
asphalt next to it, you might see your
crabgrass come up in those areas first and
you still have time to apply

(17:02):
in your lawn. If it's a dense lawn,
you know, 3 to 4 inches tall, you
still have a little time to get your
pre emergents out there. And watch your yard
year to year. If you've been putting down
pre emergents and haven't had any crabgrass for
the past
4 or 5 years, it may not be
an issue. If you have a good dense
lawn, often,
the warm season annuals aren't an issue in

(17:24):
those lawns. So consider whether you you need
to use it at all.
I really appreciate those tips. I hadn't heard
those before. And just to to kinda watch
out for those nuts edges, what are some
identifying
characteristics for the nuts edge? Because it I
know that they typically, generally, are in the
areas that it's staying a little bit more

(17:44):
moist. Is that correct?
Yes. Generally,
that's what the textbook says,
but I find them.
Everywhere.
They don't always read the book about where
they're supposed to grow,
but yes, areas where you have standing water,
it seems like to me where the grass
is struggling and it starts to die out,

(18:05):
that maybe that they just take advantage of
of the bare areas there and they're quite
prolific. They have tubers,
so even if you're mowing them off and
often you can spray them and see them
die down, but they store energy in those
tubers and will come back. So they can
be quite difficult to control when you let

(18:25):
them
grow, but they're easy to pull when you
don't have many of them. So just keeping
an eye on those and pull them. Identification
of those versus grasses,
We do have many
native
carrots, sedge plants
in Kentucky.
I mean, some of those can be such
fine blade, they look like a Kentucky bluegrass,

(18:46):
but our annual
plants like our nuts edges,
our perennial sedges, like nuts, yellow nuts edge
in Kentucky,
it will always have a triangular
stem.
And often it's easy to identify in the
summer when you mow the grass and you
come back 2 days later and it's sticking
3 inches above the rest of the grass,
feel down to the base of that stem,

(19:08):
and you'll feel a triangular stem.
Sedges have edges is the easy way to
remember that. I like that. Sedges have edges.
That's a good way to remember that. Yes,
ma'am.
I know that we have covered a lot,
and you mentioned
there that there's a great publication that is
available. Do you care to repeat that? And
if there's any other resources or places that

(19:28):
we should go check out if people have
more questions related to spring weed control for
the Kentucky lawn? Yes, absolutely. So
UK has a publication called Pre Emergence
Herbicides for Kentucky Lawns,
and I like to Google UKY
Turf,
and that'll bring you to our our web
page.

(19:49):
If you just Google UK Turf, you'll often
end up at a website across the pond.
And so you search UKY,
and that publication is at agr272.
So you can find that on preemergence. I
also
recommend
kind of if you really wanna dive into
the weeds and go a little bit deeper,

(20:09):
Purdue has a publication called Turfgrass Weed Control
for Professionals.
I mean, just be careful to check the
labels. There are a few products that are
not labeled for residential or home lawns, but
most of those products are gonna be available
to you. And it's gonna give
very good in-depth information on timing,

(20:29):
best products that you can apply.
And then also,
there is a book, if you're really into
the weeds,
is Weeds of the Northeast
by Richard Uva. Even though we may be
considered
southeast here, most of those weeds are going
to overlap here in Kentucky, and that's going
to give you really good pictures and descriptions

(20:51):
and help you identify those weeds in your
lawn. And before you send the pictures to
Kristen, you can take a look at those.
Yeah. That's that's all great information. I really
appreciate you coming on the podcast to talk
specifically about weed control for us here in
the Kentucky lawn for the spring, and we're
gonna have you on again here in the
next episode of the Sunshine Gardening podcast to

(21:13):
talk about the do's and also the don'ts
with spring lawn care. So if you're really
itching to get out in the lawn and
do some work, you'll definitely wanna tune back
in for that, and Kenneth will be back
with us. Kenneth, thank you so much again
for being on the podcast, and we hope
to hear back from you again very, very
soon.
Yes, ma'am. Thank you, Kristin.

(21:33):
That concludes another episode of the Sunshine Gardening
podcast.
We hope you enjoyed learning about spring weed
control and gained valuable insights to help you
tackle those pesky invaders in your Kentucky lawn.
A big shout out to our guest, Kenneth
Clayton, for joining us today.
To access the show notes for episode 25,

(21:55):
please make sure to visit me on the
blog at warrencountyagriculture.com.
Now before we wrap up, make sure to
hit subscribe
on the Sunshine Gardening podcast for more gardening
wisdom, tips, and inspiration
delivered straight to your ears. If you have
any questions, feedback, or topics you'd like us

(22:16):
to cover in the future episodes, please don't
hesitate to contact me. As always, we wish
you happy gardening,
and may your spring be filled with vibrant
blooms,
lush lawns, and the satisfying feeling of nurturing
nature right in your own backyard.
Until next time, this is Kristen Hildebrand signing
off. Keep growing, thriving, and listening to the

(22:39):
Sunshine Gardening podcast.
Thanks for listening to the Sunshine Gardening podcast
with Kristen Hildebrand.
If you enjoyed today's content, make sure to
hit the subscribe button wherever you get your
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Gardeners keep on digging and learning more about
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(23:00):
Kentucky garden. The sunshine gardening podcast with Kristen
Hildebrand is a production of the University of
Kentucky Cooperative Extension Service.