I have combination fertilizer + Pre-emergent weedkiller ("Crab-grass
preventer") that I bought *before* part of our lawn was dug up to
replace a water pipe.
Now I have two conflicting requirements:
1. prevent all the crab-grass seeds from germinating
2. reseed the bare areas.
Will simply covering with plywood or plastic the areas I want to reseed
while I am applying the fertilizer+weedkiller, *then* reseeding and
fertilizing (with starter fertilizer) the bare areas work?
Any better suggestions?
what kind of grass?
the typical weed and feed is BS, you're better off using a seperate
pre-emergent and then buy the cheapeast fertilizer and add 1lb epson salt
and 1lb sugar.
Personally I have never had good luck with seeding except for fescue, I
prefer sod, but then I'm in the south
I overseeded two falls ago with 40% Kentucky bluegrass, 60% perennial
ryegrass, as recommended by local seed company. Still have some left.
The fertilizer + Pre-emergent weedkiller I have is the store brand, so
even at regular price a lot cheaper than Scotts. And I got it on sale
and with a further discount for using the store-issued credit card.
About $25 for enough to cover 15,000 s.f.
What about digging up a few plugs of the existing lawn from
inconspicuous places and planting the damaged areas with those?
So your seeding for cooler northern climate? As long as ya
keep it moist and can keep the birds from eating the seed,
you should be okay
Well, at that price, what the hell.
But from what I've read, been told and experienced, the weed
and feed is useless.
Are you sure its Pre-emergent weedkiller? Typically pre
emergent doesn't kill weeds, it just keeps their seeds from
germinating and needs to be used 2-3 times a year.
A weed and feed usually needs to be applied when the grass
is damp for the weed killer to stick to the weeds and kill
them. If it's applied to a dry lawn the weed killer is
You could try it. Bluegrass and rye are both clumping
grasses, so it should work
The best defense to crab grass is proper care....mow high in hot, dry
weather, deep watering (1" per week if no rain). I bought pre-emergent
for the first time this year (Scotts, against my better judgement). I
bought the "Snap" stuff....just drop the bag of poison onto the rig and
start rolling :o)
I use hose-end sprayer for broadleaf herbicides, once, and they do a
great job....killed off most of the dandelions and others last year. It
takes at least 2-3 years to take care of seed that is already in the
lawn, but applying b.h. once, along with proper care, eliminates almost
all b. weeds. Just spot treat after that. For tough weeds, like dand.
and plantain, I sometimes use a brush with Roundup to kill 'em for sure
without hitting the good grass.
I've used b.h. on southern and northern grass, and southern grass, like
St. Augustine, requires it's own special product. You need to use them
when weeds are actively growing and when the lawn is not stressed by
heat. I fed the lawn a week or two before using it to maximize the
"actively growing" part...it fun to see the weeds shrivelling up in a
day or two :o)
We are new to our present home and I've been concentrating on putting in
shrub and flower beds to eliminate the dang mowing....I ran across an
article that advised feeding grass FOUR TIMES A YEAR! Maybe for
southern grass that has to grow in sand, but it guarantees you will be
mowing a lot more...we feed ours mostly with a mulching mower, unless I
need to bag grass clippings to use as mulch. My neighbor has big maple
trees, so I rescued a lot of his leaves to use as mulch on my flower
beds. I have "repurposed" a lot of stuff in planting/caring....plant a
shrub, remove the largest rocks (we have a lot) and use the rock for
mulch around some beds (with landscape cloth, of course).
Epsom salts is good for palm trees if they are puny and yellow. It is
magnesium sulfate, and allegedly helps plants take up N. Sugar? I have
never heard of using sugar for gardening.
It is too late for pre-emergent weed killer, unless you live pretty far
north. Save that for next year (very early spring). Reseed the bare
spot, concentrate on getting your lawn in good condition otherwise
(proper mowing, watering, etc). If you have a lot of broadleaf weeds,
treat them later in the spring, before weather gets hot and dry.
Pre-emergents are the nastiest chemicals, so you don't want to waste it.
On Friday, April 11, 2014 6:59:41 AM UTC-4, NorMinn wrote:
It depends on what weeds he's specifically trying to prevent
from germinating. If it's crabgrass, which is what people are
generally using pre-emergent for and most concerned about, it's
not too late for much of the USA. It's been a cold Spring
so far here in the NYC area, crabgrass takes warmer temps to germinate,
but I'd get it down right away. There are also products like Dimension,
which is a pre-emergent, but also provides post emergent control, ie it
will kill early stage crabgrass too. No reason you can't put that down
now in much of the USA.
There are pre-emergents that are compatible with new seeding,
eg Tupersan, but it costs more than the typical pre-emergent and
is harder to find. Depends on how big the re-seeded areas are.
If they are small, just not-applying pre-emergent there is probably
easiest, cheapest. Use starter fertilizer instead.
As to the claim someone else made, that only the products that are
sold seperately for pre-emergent are effective, IDK what that is based
on. A lot of them have the same chemical, combined products can be just
as effective and certainly are easier to find.
I think the pre-emergents are more toxic to aquatic critters and more
persistent in soil. Broadleaf weeds are much easier to kill with
herbicides that are less toxic and break down more quickly....lots of
folks don't read labels and follow the "more is better" principle, which
is why our waters are so polluted.
My rule of thumb is to get the pre-emergent down before forsythias
bloom. Here in Northern DE its usually the first week of April. Areas
of lawn that warm faster next to asphalt drive and road will germinate
crab grass sooner and even earlier application is needed.
For OP, I'd put down pre-emergent right now and seed without starter
fertilizer which is redundant.
Pre-emergent only works before crabgrass sprouts. Multiple applications
are only necessary for weeds like Japanese stilt grass where seeds may
sprout all season long.
On Friday, April 11, 2014 8:33:46 AM UTC-4, Frank wrote:
The typical, common, pre-emergents that you find in a garden center,
HD, Walmart, etc are not compatible with seeding. They will prevent
the grass seed from germinating too. He can either:
A - Use typical pre-emergent on lawn areas that are not being seeded and
and starter fertilizer in seeded areas, which is what he proposed
B - Use a pre-emergent like Tupersan that allows seeding.
That is true with the vast majority of them. But some, eg Dimension,
are also effective against very young stage plants too. So, if you
think it may be too late for a regular one, Dimension would be a good
Yes. He's got the mix and we don't know what it is.
For myself, I'm trying something different this year.
It's a Spectricide weed stop product that they say can be put down at
any time and is good for 5 months.
I'm in northern Indiana, and it is too late here to be sure of best
application. Because the stuff is so toxic, I feel it is wiser to hold
off a year rather than spead the stuff around when it is too late to get
best effect on weeds.
I'd be sure to follow directions, as seeding must be delayed for most
p.e.h.'s. Reading labels helps!
On Friday, April 11, 2014 9:41:15 AM UTC-4, NorMinn wrote:
Since you previously posted that you only used a pre-emergent
one time, how would you know that it's too late to apply now for
crabgrass control? There is a lot of conflicting data on when to
apply. At most, northern Indiana should be near the end of the
ideal time to apply, but not out of it.
Especially since it's been a cold Spring so far. If you put it
down too early, it can be losing it's effectiveness before
crabgrass even germinates. For that area I would think first
couple weeks in April is about right.
If it's delayed, it's pretty much delayed to Fall, unless you want
to try seeding in summer.
Other plants and weeds have sprouted....we had a blizzard 'bout three
weeks ago, followed 2 or 3 days later by 50 degree daytime temp. It has
been warm/cold alternating for a while. I think that if other weeds are
coming up, the crabgrass is ready, too :o)
On Friday, April 11, 2014 3:27:21 PM UTC-4, NorMinn wrote:
All plants and weeds don't germinate at the same time. Crabgrass
needs soil temps consistently in the upper 50's to low 60's. That's
why broadleaf weeds can be a problem in May/June, but crabgrass isn't
a problem until Jul/Aug. Depending on where the OP is located, it
could be too early, ideal, or too late for pre-emergent. Here in NYC
area, it's about the right time right now.
Lawns are not one of my skills, but the weather the last 2 years damaged
what was not a great lawn to start with (I have great weeds) and I did
In Minneapolis the suggested period for pre-emergent herbicide
application is May 5-20, on average. And we had a late spring. You might
want to check at a competent garden center.
For grass seed here, may not apply elsewhere:
Grass can be low maintenance or high maintenance. High maintenance
presumably looks better, but needs more water and fertilizer.
The packaged grass seed mix you get at hardware/box/similar stores is
"genetically improved", which means there is a patent (or whatever) that
restricts the sale. "Improved" very likely means high maintenance.
Garden centers are likely to have seed mixes that have been around for a
long time and are low maintenance. Likely sold bulk.
Depends on how much work you want to do.
(The package mix I got years ago also does not match the rest of the lawn.)
On Friday, April 11, 2014 6:55:59 PM UTC-4, bud-- wrote:
I have to disagree with the last part. Improved can mean many
things and it's most often not an indication of higher maintenance.
There is a much bigger market for grass that is low maintenance for one
thing, than one that is high maintenance. That's true in both the
home and commercial markets, especially today with increasing restrictions
on fertilizer use in many places. Some of the things that
get improved are disease resistance, insect resistance, drought tolerance
ie less watering, slower growing, better color, finer texture,
quicker to green up in spring, better color over winter, etc.
With any of those it's almost always a compromise. You can't get
everything in one grass. But as an example, I'd sure take one of the
many newer improved tall fescues over the older Kentucky 31. The
new ones are much finer blades that look a lot better for a lawn.
IMO, high maintenance usually goes along with having a showcase type
Anyone that is really interested in the ratings, there is a lot of
data from the NTEP (national turf evaluation program) available
on line. They rate many of the grasses in the above and more
performance catagories at test sites across the USA. Using that can
help you decide what's best for you in terms of your needs and priorities.
Around here garden centers have similar stuff to what's sold at the
big box stores. If you want a specific grass, you can also find
it online sometimes.
That's one potential problem with spot seeding. It helps if you
at least know what kind of grass is there now as a start. If you
seed a big bare spot in a bluegrass lawn with K31 tall fescue,
you're probably going to notice it. Most people have no idea of
what's there though.
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