1- Do not fertilize now. With the young grass and heat it will burn it up.

2- I would go ahead and mow. Set your mower on it's highest setting so you're not taking too much off of the tall grass and don't worry about the shorter stuff for now. Mowing new grass will help it tiller out and thicken up.

3- Don't put down any fertilzer now.

That being said, your lawn was seeded at the worst possible time of year unless it was a warm season grass like bermuda. Unfortunately new houses just work out that way sometimes. Cool season grasses are best seeded in the fall. For now just do the best you can and plan on reseeding this fall. August through October depending on your location is the best time. You can put down an organic fertilizer now if you want as they won't burn the new grass but do not use a synthetic fertilizer.

Let us know where you are at, what type of grass you have, and how much sun/shade the lawn gets. That will help with recomendations on where to go from here.

This post was edited by ForsheeMS on Fri, Jul 18, 14 at 10:16

I have some minor disagreement with the above, but it's more a matter of methodology than anything else.

1) Don't use synthetic fertilizers between June 1 and August 15--ever. However, if you want to feed (and new lawn is probably getting very, very hungry as the seed resources exhaust themselves), feed with Milorganite or any other organic whenever you want.

Next year you won't have to, but this year the grass is simply too young to have much stored in the way of resources.

2) As the above, mow high and mulch mow the clippings back onto the lawn.

3) Using an organic, you can mow whenever you wish. If the organic was just put down, always mulch mow (which is good advice at any time, actually).

Extra--for a new lawn, you're stuck watering through summer to get it to survive. By next year, you won't need to do that and normal watering will be fine.

Thanks for the reply.

I am in Pennsylvania, near Philadelphia. The grass is 39% AST 1001 Tall Fescue, 39% AST9003 Tall Fescue, 14.5% ASP0112 Perennial Ryegrass, and 5% Geronimo Kentucky Bluegrass. Back of the lawn is shaded by trees, the front is mostly shaded in the morning but fully exposed to sun in the afternoon.

So you are saying I can't do much about it right now, just wait until August and reseed?

you're stuck watering through summer to get it to survive

But hey, you're halfway there! Just a bit more to go.

crikey ...

do not attempt to burn new seedlings... i dont care what formula ....

i have never seeded a part of my lawn.. when i did not 'expect' .. to have to reseed spots for a few years..

you have extremely high 'expectations' of the process ....germination ... vermon.. weather.. etc ...

if you wanted sod like results inside two years.. you should have sodded ..

if you set aside your 'expectations' ... you are probably doing good.. considering the timing and all ... pix might change this comment ...

that said... early fall.. is seeding time.. days warm enough to germinate.. and cool nights for recovery from a warm day ... in my MI.. i would be setting down some seed in late august.. so that by the time it germinates inside 2 weeks... its prime grass season ... you have to adjust that for your area.. though it cant be all that different .....

water as best you can for the next two months... start bringing it down to about 3 inches... a little at a time... individual plants will start multiplying...

and then just lightly rake the soil.... and seed the bare patches ...

i would wait to fert until next spring .... its not really a food issue at this point ... IMHO ... at this time of year.. its water.. water.. water ....

have you talked with the guy who put it down??? .. can he get you some matching seed???

ken

>>So you are saying I can't do much about it right now, just wait until August and reseed?

On the contrary. I haven't seen photos, so maybe the entire seeding is too thin, patchy, or poor to bother saving. But maybe it isn't.

If it's OK, keep watering from now until end of summer (fortunately, this summer has been light on water needs--the key this year is to keep it from drowning!)

Feed organically. In your locale, Milorganite will be easiest for you to get, and it should be available at any big box store. You can always feed organically if you want to, even in summer.

Overseed around August 20th-September 5th if you need to thicken up what you have. Use appropriate (2 to 3 times daily) watering for the seed until it sprouts fully, then back off slowly to give the grass time to adjust itself.

Fall is the time to heavily feed the lawn--overseed or not, feed September 1st, October 1st, and when growth stops (for you, usually late November).

Cool season grasses shouldn't need or receive fertilization, newly seeded or not, during the summer months. All that does is stress them into excessive growth when they want to go dormant. And bump up your water bill.

As to new lawns getting "hungry" without additional fertilization, if the soil bed was properly prepared, all the nutrients required for healthy growth should be present

>>Cool season grasses shouldn't need or receive fertilization, newly seeded or not, during the summer months. All that does is stress them into excessive growth when they want to go dormant. And bump up your water bill.

Organic. No excessive growth because it never dumps nitrogen. No watering required.

Never use synthetics during summer, of course, on the lawn. That would be a bad move.

While the seed bed should have been prepped...the probability of that is rather low for a builder's lawn. Additionally, young grasses, seeded at the wrong time, simply don't have the root systems and fungal associations required to dig for resources.

They need a little spoon feeding. The roots will grow in during fall, and next summer will be considerably different.

the problem with any kind of seed.. for any kind of plant.. is that in july and august .... its just too hot ... and watering is a nightmare..

on a tiny seedling with roots that are barely in the soil ... if it gets hot at mid day.. and the soil dries to a quarter inch.. the seedling will die ... it just cant take the ups and downs of the stresses ...

that is why.. in gardening .. a vast majority of seeding.. again.. of any type plant.. is done in spring ... cool days.. cooler nights... and ambient moisture deep in the soil ... and as the soil warms to the porper germ temps.. the seed triggers ....

morph said: Overseed around August 20th-September 5th

and that is because of what i said above .... two weeks of warmth for germination ... and then as the sun goes into decline.. days start moderating ... and nights get cooler... cooler nights are a recovery period for the onslaught of day ...

if you go much later into sept.. e.g. in my MI ... you may not have the day heat.. to germinate ...

and all this theory.. is based on an average year ... whatever that is.. lol ...

good luck

ken