Weeds in a new lawn

bazfan, Apr 26, 2:49am
Hi Guys, i'm sowing a new lawn in AKL and the week of fine weather has seen the grass seeds grow to about 20mm. There is however some weeds in the area. Was wondering whether I should just apply some round up gel to them to kill them and allow the grass to grow alongside them. Is this gel all good? I'm using it on some ivy on a pohutakawa tree
arabelle, Apr 26, 3:48am
Have a party and get the visitors to go and tweak the weeds out. , the less use of THAT gel the better.
eagles9999, Apr 26, 5:05am
Because its a new lawn there wont be many weeds so best to remove them by hand. Use of Round Up or any weedkiller is discouraged on a new lawn because of the likelyhood of it spreading and killing your new grass
maclad, Apr 26, 5:53am
Generally you will get weeds in a new lawn, you really cannot avoid it. Do not use roundup as it will kill out your grass as well. I would just let them go for now and control by mowing the lawn a little longer. Weeds need bare soil and sun to grow and if grass is a little longer this discourages them as at soil level it is more shaded. In fact a new lawn should only have the top of the grass cut off on the first mow and then every successive mow lower the mower until lawn is cut at the desired height. Preferably not too short. It you cut it short on first few mows then you may rip out the new plants. Mowing will also kill a lot of the weeds. A new lawn should not be weed sprayed for 6 months to avoid damage to the grass. I have also controlled weeds in new lawns by digging out with a knife but this is not always practical. Once the lawn is 6 months old you can use a broadleaf turf spray to get rid of the weeds.
tweake, Apr 26, 5:53am
depends a lot on what weeds they are and what soil was used for the lawn.
unless it is weed free soil, your going to get a lot of weeds coming up, simply because the soil is full of them and the disturb soil gives them a chance to germinate.

if its only broadweeds and nothing to nasty, i would wait until grass is up a lot higher (50mm plus) and use a brood leaf spray like pastureclear, turfix etc. need to wait till grass is long enough otherwise the sprays will damage the grass.
if you roundup each weed you could be there for a long time and risk spraying the grass.

also if you used a typical mix of grasses, what your seeing is probably just the first type of grass. the other types of grasses are slower and will come up over the next few weeks or so.
maclad, Apr 26, 5:55am
I should have added that by mowing you will encourage the good grass to grow and spread and that will also help to smother the weeds.
tweake, Apr 26, 6:17am
i disagree a bit here.
mowing will deal with weeds that stick up but won't do anything for the short weeds, they will live happily under mowing height.

if you wait 6 months to spray the weeds out you will end up with a lawn looking like its been shot up! and possibly need to oversow to fill in the gaps.

i would get rid of the weeds as early as you can which will allow the grass to fill in and dominate.
maclad, Apr 26, 6:22am
This is and has been recommended practice for many years and it does work.
tweake, Apr 26, 6:46am
recommended for who, the guys selling the grass seed?
harrislucinda, Jan 24, 5:54pm
yes I would spray now before sowing new grass seed