Recently Over-seeded Lawn

Having reseeded and over seeded large areas of the lawn, I was about to use a reputable Fertilizer/Weedkiller but, reading the instructions, discovered that this product can only be applied TEN weeks after overseeding; this is true with all such feed/weedkillers.

During that time, the lawn will lose strength and weeds will invade ...

What can I use during these ten vulnerable weeks to invigorate the grass and keep the weeds at bay?

Many thanks for your suggestions!

 

I think it's probably best not to use anything.
But maybe a liquid feed would be ok,you would also be feeding the weeds though.

 

Many thanks, Pete, for your advice; it has led me to choose a liquid feed which I will apply today.

Perhaps I could report on the result, provided this does not infringe Forum rules?

 

Well I'm not a lawn grower as such so was hoping for input from others, it just seemed to be the only option.

Yes feel free to report back.

 

It’s due to the young plant is susceptible to herbicides. You want a low N feed to help it on its way but if you dressed with fresh topsoil that should have enough traces in it to get the germination well on track.

 

Thank you, Liz the pot; the liquid feed I had chosen, luckily, is indeed low on Nitrogen.

The label hints at rapid results; I'll report after one week and, if results are positive, mention the name of the product (unless that is deemed to be advertising).

 

by all means mention the product. It’s very helpful to know what you are using and how you are applying it.

 

Hello pete and Liz the pot,

The product I used (Supreme Green - Lawn Feed– Liquid Concentrate – by Empathy [biological) proved successful, as can be seen from the sides of the lawn on the Long Shot where the seedlings have thrived (image 1);

the center of the lawn is more of a concern: there is no evidence of the over-seeding and, furthermore, it already shows creeping grasses (?) lowering their ugly heads (image 2) which makes me dread a possible return of what happened in 2020 (image 3) which was an umitigated disaster.

The entire grass was chemically killed in 2021 and a whole new lawn re-sown … my dilemma is that if, at this juncture, I kill these new creeps and re-seed, it would set me back again another ten weeks before being able to feed/weed kill, by which time the summer will be well advanced … somewhat of a vicious circle.

I am puzzled to hear that on gold courses they apparently constantly overseed AND fertilizing/weed-killing at the same time; how do hey do that in view of what we have discussed?

Looking forward to your thoughts!

All best,

LAO

 

We don’t use weed killers after reseeding on my golf club. There’s not much choice for selective herbicides now either.
You can apply some fertilisers before and after seeding depending on the product used.
Say on a green we tend not to go high on N as the grass growth needs to be controlled or else you cut the grass in the morning and in the afternoon the extra growth effects the ball speed so you aim for a controlled growth pattern close to a natural one.
Tees are different and the par 3 ones tend to need constant repairs but again we don’t blanket spray them with a herbicide as they are well kept and only require the odd weed removed by hand.
We do have to treat diseases though and that does require a blanket spray on both areas.

Can you explain a bit more about creeping grasses.

what height is the cut?

I’ve tried the same fertiliser a while back, see photo. It’s fine, maybe not the best as it’s expensive long term but it’s fine if treatment is constant and other practices managing the grass are included.

 

Thank you so much!

Are you a greenkeeper and looking after a golf course? Your lawn looks fantastic.

Anyhow, your advice is precious. I have cut the grass yesterday to show you some results. The height you ask about (see pic. LS) is 3 ½ which, as far as I can make out, would correspond to about 30 mm (maximum on my mower being 35 mm – minimum is 6 mm).

You will probably say that “longer” is better but my wife and I love the “putting green” look … its baize-like lushness, homogeneity, etc.

Two photos were taken this morning: the LS shows the overall aspect which, as you can see is a bit like having a two-tone lawn, with the yellowish patches you asked about; they have always flummoxed me because they appear in early summer and gradually get worse as temperatures rise; what is puzzling is that they always appear in roughly the same places, despite scarifying, feeding, repeatedly renewing surface soil, etc.

Particularly frustrating (see pic. CS) are the small patches showing earth here and there and which I can never completely get rid of! As for this generally mottled effect, I just know what that comes from. How do you, on putting greens, get these vast areas where there isn’t even a six-pence worth of bald patches?!

Yes, you’ve got there the feed I had chosen. Re: your comments on it, do you have other suggestions?


(add pics of Manual – Lawn LS – Lawn CS)

 

I did have a small business for around 16 years and this year I was snapped up by my local golf club which was nice and I work with a great team. It’s a different challenge which I like and lots of variation.

let’s see if we can get to the bottom of why that grass is yellow every year.

first is to check early morning just as the sun comes up to see if you can see any web like material on the grass in those areas.

Have you lifted a section up to see if there are grubs underneath?

what’s the soil like underneath?

has the lawn ever been aerated ie. Hollow tine and dressed.

how do you apply the liquid fertiliser?

If you step into the more pro type fertilisers you really need to use a knapsack sprayer and get the calculations correct where as with the one you use it can be applied via watering can or even one of the miracle gro feeders.

I’ve used Amvista L9 liquid seaweed which was ok.

With the greens it’s a case of constant work to keep them in trim and a battle as grass tolerates cutting rather than loving it and more so when it’s super low.

on domestic lawns we tend to go higher but 2 inch is a good starting point but you can keep a lawn short, it just needs more work.
If I remember correctly I was cutting the lawn in the pic I posted with a hand cylinder mower but was spending a lot of time looking after it.
Below is the same lawn but on a higher cut and that’s the density to aim for if you like silky lawns.

 

Once more, Hello,

Thank you again. I am aware that this is taking a lot of your time; please say if I am over-stepping the mark!

To answer your questions first:

No, there is no web like material

I have lifted sections and cannot see grubs

The soil underneath is normal topsoil (bought at Wickes)

Yes, the lawn has been aerated over the years, including hollow tines

I apply liquid fertilizer with a 12L knapsack with a pumping lever to fine-spray.

I don’t know if these photos are clear or detailed enough for you to see what is going on here.

The concern is that I am dealing with grass which was sown brand new in May 2021, after the lawn had looked as in Image 3 of my post of last Sunday … a year later, the bad grasses all seem to be returning: the cycle seems to have re-started (goodness knows where they come from).

Images 1, 2, and 3 of the attached were taken after a gentle scratch with a fine tine rake and I hope the pics are sharp enough to enable you to determine which type of grasses they are.

Image 4 shows what happens if one pulls out one of those “bad” tufts: they leave a gaping hole which eradicates all the hard work one has spent seeding, overseeding, etc.

Looking forward … if you have time …

 

No worries.

Unfortunately problem grasses do creep in and there are 10,000 species of grasses so they can be quite hard unless you start examining in great detail to find the exact type of grass but do the problem grasses produce rapid seed heads?

do the problem grasses look pale compared to the other grass types after a feed?

regarding the spray, you want a course spray rather than a fine spray. I’m pretty sure it’s not a foliar feed and I found it required more than what they stated.

different grass types have slightly different pH values which you can control during extent so depending on the type of grass that’s the problem you may be able to combat it but at the same time it’s working out what the other grass is and it’s requirements.

do you feed the lawn with any other type of lawn feed?

if you top dress does the yellowing improve?

have you taken any pH tests to see what it is all be it most domestic tests will be a rough guide only?

 

Looks like an invasion of Poa annua the devil well in my case it is . You are based in London not much rain recently ? Poa annua is usually the the first grass to show signs of stress turning yellow straw like .

If you want to have the putty green look it be far better / cheaper in the long run to just start again with grass that will tolerate being cut short like Liz has mentioned .

 

"Invasion" is right, Perki (I wish my lawn were perky but, by gum, it ain't!); as we all know, invasions are distressing in the extreme and, in the grand scheme of things, an invaded lawn is a trivial matter; however, as I am aware you'll appreciate, greenkeeping can be addictive.

Liz's questions:

at the moment, I don't use other feeds because those I have contain weed-killers
I am not sure about top dressing
I haven't taken any pH tests

It is possible that the invasion is due to neighbouring gardens (see attached Ajacent 1 & 2) which are currently unattended due to inevitable circumstances.

What is particularly upsetting is that the creeps have returned "hay" presto after the lawn was only just completely renewed last summer by a firm who first completely killed the existing grass - I am sure they did the best they could but I am beginning to wonder whether the Poa annua (if that's what it is) resisted the herbicides, because the current return-visits are in the same places.

If I were to take the plunge and yet again start all over, are you, Perky, referring to Bents and Fescues? ... And how would I go about this? ... You may be aware that grass experts in London are extremely few and far between, and most of them have disappeared ... I used to be friends (long story) with the head groundsman at Wimbedon in the eighties (Fred) but he is retired (or worse) and the existing one is no doubt unavailable (anyway, they no longer do that lovely grass, due to the brutality of the contemporary Wizkids who have become too fast for their own good and need to be slowed down so that the game remains possible).

Liz the pot, a quick question: I am intrigued by your suggestion that Empathy's Supreme Green is expensive (at £7.49/litre) whilst Amvista L9 costs £12.75/litre (?). Is it possible that the Supreme Green has encouraged the flowering of the bad grasses (there is indeed an inordinate amount of flowers in the grass at the moment!)?

Anyway, thank you everyone for your continuing support and I look forward to hearing if you know of anyone in the Wandsworth area who might be willing to help me conquer the challenge.