Sulphate of Iron application rate through sprayer

PeteFalk78

Hi,

I have a 16l knapsack sprayer that I want to use to spread SOI. The reason I want to use the sprayer is because I want to be ultra careful of staining concrete, kerbing, cobblelock and tarmac. A spreader is out of the question especially a non-drop one.

I can't find any solid information on

1) How much SOI I should put in the sprayer?
2) How much lawn should I cover with 16l? I have approx 450m2 to cover.

Many thanks.

lk67

PeteFalk78 wrote: »

Hi,

I have a 16l knapsack sprayer that I want to use to spread SOI. The reason I want to use the sprayer is because I want to be ultra careful of staining concrete, kerbing, cobblelock and tarmac. A spreader is out of the question especially a non-drop one.

I can't find any solid information on

1) How much SOI I should put in the sprayer?
2) How much lawn should I cover with 16l? I have approx 450m2 to cover.

Many thanks.

I wouldn't use Sulphate of Iron through a sprayer as it will clog and/or corrode it. A drop spreader on a calm day is your best bet. Alternatively use a watering can with a spray bar but you might have to experiment with the dosage. Test a small area first, it works pretty quickly.

PeteFalk78

My understanding is that it will can be diluted in luke warm water.

lk67

PeteFalk78 wrote: »

My understanding is that it will can be diluted in luke warm water.

True but I'd still be concerned about corrosion unless it's an all plastic sprayer. Most have some steel or copper fittings.

This was the first return from Google with regard to rate. Rinse well!

http://homeguides.sfgate.com/use-sulphate-iron-kill-moss-24692.html

PeteFalk78

Thanks for the advice LK.

The sprayer is all plastic.

That site advises 140 grams of SOI for 18 litre knapsack and apply over 92m2

Some other sites recommend to mix anywhere between 200g to 833g for a 20 litre knapsack and apply over 333m².

lk67

PeteFalk78 wrote: »

Thanks for the advice LK.

The sprayer is all plastic.

That site advises 140 grams of SOI for 18 litre knapsack and apply over 92m2

Some other sites recommend to mix anywhere between 200g to 833g for a 20 litre knapsack and apply over 333m².

It's the grams per sqm that's important but I'd be cautious if I were you. I'd prefer to do it twice at the lower dosage, say two or three weeks apart. Watch for drift from the sprayer. As I said, I'd stick with a drop spreader!

Zardoz

PeteFalk78 wrote: »

My understanding is that it will can be diluted in luke warm water.

Its a disaster in a sprayer ,trust me I tried it ,even with warm water.
The nozzles kept on clogging,it did my head in.:mad:

Ended up using a watering can ,one can per 50 square yards.
I usually use 1-1.5g per square yard for a light greening up ,and 2-3g per square yard for killing moss.

lazybones32

1) Calibrate your sprayer: adjust the nozzle to the preferred action (fine mist, etc). Put 1 or 2L of water into it and spray an area of dry path/concrete, walking at normal speed. Wet it, not douse. Measure the area after.

If 1L covers 9m2, 16L will cover (16 x 9 = 144m) NB: use some markers to divide the lawn so you know what areas you've already treated.

2) What'proof' is the SOI? This determines g/m2... at 100% 25g/m2 could kill the grass (my tin recommends 35g but I sprayed 10g/m2 yesterday and the moss went brown within minutes - 35g would've killed the lawn.


3) Mix SOI withwarm water at no more than 1kg/10L. Mix well and it should dissolve easily. While spraying, give the ksack a few shakes on your back to help mix it up again as SOI settles quickly and could mean higher concentrations as you near the end. Rinse sprayer thoroughly after use

lazybones32

1) Calibrate your sprayer: adjust the nozzle to the preferred action (fine mist, etc). Put 1 or 2L of water into it and spray an area of dry path/concrete, walking at normal speed. Wet it, not douse. Measure the area after.

If 1L covers 9m2, 16L will cover (16 x 9 = 144m) NB: use some markers to divide the lawn so you know what areas you've already treated.

2) What'proof' is the SOI? This determines g/m2... at 100% 25g/m2 could kill the grass (my tin recommends 35g but I sprayed 10g/m2 yesterday and the moss went brown within minutes - 35g would've killed the lawn.


3) Mix SOI withwarm water at no more than 1kg/10L. Mix well and it should dissolve easily. While spraying, give the ksack a few shakes on your back to help mix it up again as SOI settles quickly and could mean higher concentrations as you near the end. Rinse sprayer thoroughly after use

PeteFalk78

I ended up using the watering can. At 8 litres it covers 14m2.
I put 250g of SOI per watering can so approx 18g of SOI per m2.

Moss turned brown after 20mins. Thanks for all the advice above.

Zardoz

PeteFalk78 wrote: »

I ended up using the watering can. At 8 litres it covers 14m2.
I put 250g of SOI per watering can so approx 18g of SOI per m2.

Moss turned brown after 20mins. Thanks for all the advice above.

18g per square metre :eek:,that will kill the lawn ?

5g per square metre is the maximum dose recommended ,anymore is toxic
See here
http://www.lawnsmith.co.uk/blog/how-to-feed-lawn/using-ferrous-sulphate/

PeteFalk78

Zardoz wrote: »

18g per square metre :eek:,that will kill the lawn ?

5g per square metre is the maximum dose recommended ,anymore is toxic
See here
http://www.lawnsmith.co.uk/blog/how-to-feed-lawn/using-ferrous-sulphate/

It says on the instructions to use 30g per m2. So I though I was being conservative.
Anyway my "lawn" is 95% moss anyway so it won't have much grass to kill

PeteFalk78

Sulphate looks like it did a good job and my grass hasn't been damaged.

Some of the lighter moss is black the whole way through but some of the heavier moss is still a little green closer at root.

It's been nearly 3 weeks. Shall I scarify now or leave it a bit longer?

Zardoz

PeteFalk78 wrote: »

Sulphate looks like it did a good job and my grass hasn't been damaged.

Some of the lighter moss is black the whole way through but some of the heavier moss is still a little green closer at root.

It's been nearly 3 weeks. Shall I scarify now or leave it a bit longer?

I'd scarify now,ideal conditions and right time of year to do it .