OutdoorKing Repair Forum Forums General Discussion Forum Off Topics Lawn Help Sb45 user

Hi all
I'm not sure if I'm posting this in the correct area, please let me know..

About a year ago I rebuilt my Scott Bonnar 45 which is still running well... As a result, I then went out and relayed Santa Ana couch on my front lawn <as you do> however I'm having trouble getting the bowling green surface I was hoping for. I'm not sure if I'm not giving it the right love, or whether my Scott Bonnar is contributing to it..

The SB45 cuts well, and I mow weekly. However I seem to always have a off coloured lawn like it's been cut too short.

I cut it approx 20mm high, and because it's cut regularly I don't think I'm taking more than 1/3 of the leaf off.
I water it 2 to 3 times a week
I fertilise with a munns golf course green every 8-12 weeks.
I had the reel re ground when I rebuilt the mower (12 months ago)
When it was layed I removed 100mm of the poor soil, and replaced it with 60/40 sandy loam.

I also recently top dressed it with 60/40, and used a lawn leveller to get it flat, but still appears a bit lumpy...

Any advice or tips.??

Hi Barryjnr, and nice to see you back on the forum.

My advice is to not use your Scott Bonnar 45 on lawn that has been top-dressed with loam that contains sand. This would be like feeding sandpaper in between the reel and bedknife and blunting it immediately.

You will have to get the reel and bedknife sharpened again to achieve a satisfactory finish, and not use it where sand is present

Hi Barryjnr,

If you can take some pics that would be great. It can be really frustrating trying to get it right, sorry if I'm asking too many questions here but I'll try and cover the most common things first.

20mm is a good height to mow couch and mowing once a week should be fine. When you say it's an off colour like it's been cut too short, does it appear scalped? Is the colour uniform across the length of the leaf or is it only the tips? How is the thatch buildup?

When you water, do you give it a deep watering or a short water by hand?

I've used Munns golf course green myself and I've been quite happy with it. Have you checked the ph level of your soil? Most Australian soils tend to be a little acidic and as a result the lawn will have trouble absorbing the nutrients in the fertiliser. If the ph is somewhere between 5.5 - 7.5 it's fine, otherwise you may need to add some lime or iron sulphate to correct the soil.

When you top dressed, was the mix very finely screened? I use washed river sand and it's always gone down beautifully flat with a leveller, just like a billiard table. I once bought a bag of top dressing soil from the hardware store however, and it was absolutely terrible. It had small stones, bits of bark and even a piece of broken glass in it, though it was specifically sold as lawn top dressing.

Also, is your lawn in direct sunlight or does it get partial shade or full shade?

As for the bowling green.. a true bowling green finish is almost impossible to get at home as the maintenance and equipment required is extensive. Golf greens aren't normally of a bowling green standard and even they are hard to achieve at home. Top golf greens are often dug out and lined with plastic, have special drainage installed, then gravel and a sterile sand medium is put down. The greens are contoured to allow perfect run off and they're usually placed to get good sunlight, especially in the morning and good airflow across the surface. So obviously if you're getting close to a greens appearance you're already doing well and I wouldn't stress too much

Michael

Thanks Deejay and rolla16v.

I will take some pics tomorrow, but a bit of extra info which may give context.

I gave it a very light top dress (approx 5mm to 10mm across 100sqm) so still had tops of the leaf showing. In fact, I think I semi achieved the goal of filing some low spots, but still feels bumpy.. I've seen a few clips online of people mowing with Scotty's and the mower appears very steady, whereas even though the lawn looks flat i feel lots of small bumps when mowing..

For my top dressing, I used a mix from local yard. They mix it up themselves and was very clean, without any lumpy bits. I was worried bout using river sand as I had read that it's best to top dress with the same mix as what is already there, else it may cause draining issues?.

I think I will get the blade re ground <is it normal to do this every 12 months anyway>?

I'm not sure if it's scalped or how to tell if there is thatch build up? Help. It does appear that the blades are not green all the way through, and hence the poor colour..

I water the lawn for an hour using the hunter type sprinklers (was advised this would be the equivalent of a 20-25 min water using old style pop up spray sprinklers. And the lawn gets at least 7 hours of sunlight a day

I haven't done a PH test, but will do this

Thanks once again.l

One of the advantages of using river sand is its excellent drainage qualities, but as long as what you're using is finely screened and levelled, it shouldn't be making your bumps worse.

Scalping is simply caused by removing too much of the grass length at once and exposing the stems. If you're confident that you're only removing the top third of the lawn when you mow, it's fine. The thatch layer is the build up of dead material and runners that is between the soil and the actively growing grass on top.

As for the watering, an inch or so once a week is usually enough. The key to building a strong and healthy root system is to water deeply rather than regularly. This encourages the roots to grow deeper and increases the drought tolerance of the grass. Anything you can do to improve the health of the grass will not only improve the appearance but also it's ability to resist disease and pests.

Start with the PH test and I'll keep an eye out for your pics.

Unless you want to do a re-grind of the cylinder reel and bedknife every week, don't use a domestic cylinder mower on sandy loam.....they are not designed for this.

Most bowling clubs have an old industrial Scott Bonnar Queen or equivalent in the tool shed that has an old reel and bedknife that they use after top dressing or use another machine that needs sharpening for that purpose.

Re: Sharpening schedule, you have your reel and bedknife re-ground whenever the reel is blunt, damaged by foreign objects, or the quality of cut is really degraded and therefore noticeable.
By the way, a BMS Bedknife buddy will help maintain the straight edge of the bedknife which will assist in the quality of cut.

Few pics of the lawn..

I'm thinking I may be having a thatch issue

I think you may be right, does it feel spongy when you walk on it? If de-thatching is required you can hire a vertimower or pay a contractor to do it for you. I don't have any experience with it myself so you'd have to make some enquiries. It may be worth coring (aerating) also. If you know of any contractors that provide free quotes it wouldn't hurt to ask them their opinion on what's required and how much to do the vertimowing. Definitely do the PH test still as the soil could be contributing to the issues just as much as the thatch.