Dealing With Moss In A Summer Lawn

Apply Summer Feed First (should control it); Mosskill Later, If Necessary


Treating a lawn for moss is rather like a doctor treating a sick patient. The first thing to do is control the suffering - usually with drugs or other chemicals - then work on changing, if possible, the conditions which caused it. And just like any sickness or ailment, treatment can be applied AT ANY TIME. It's just that some times are more cosmetically amenable than others. Now, the summer, is such a time.

Before I go any further, can I apologise to those of you who tried my autumn moss treatments described last year (click 'moss' link at side), but have found moss re-growing in their turf this year. It's my fault, not yours. I should have made things clearer. In case you are sick of hearing about moss and don't want to read further, here is a quick prognosis:

• keep zapping moss as soon as visible, any time of year
• rake out some of moss if it looks bad
• apply liquid lawn feed (usually all that is necessary)

All pests, diseases and disorders have one thing in common: They are all extremely resilient and enduring, able to resist the most adverse conditions and re-establish at appropriate times. The ways they do this is a fascinating study in itself - one which would teach we humans a thing or two, but this is for another day.

MOSS NEEDS REPEATED TREATMENTS
Consequently, moss is difficult if not impossible to eradicate AT ONE ATTEMPT; it has to be ground down over a period of time with REPEATED TREATMENTS. But hold on. I'm not talking about all the hard work you did to aerate and loosen your turf. I'm talking about another dose of ferrous sulphate in water.

NIP IT IN THE BUD
I'm sorry I didn't make clear that you need to watch the turf closely for signs of regeneration, then nip it in the bud. This is what I did with my lawn. The moss problem reduced significantly, right from the off. But I then wanted to change the conditions to eradicate it completely.

AUTUMN TURF TREATMENT HAS NOT BEEN WASTED
This is where the turf aeration and top-dressing comes in. It hasn't been wasted. And it's not even absolutely necessary to contain rampant moss - another dose of ferrous sulphate will do this.

As the battle continues, moss is contained to a smaller area of lawn, perhaps just the odd patch or two. This happens fairly quickly. So what I did then was apply ferrous sulphate with a hand sprayer; but if it had spread too far, I treated the whole lawn (this is what I did early last November). Having said this, however, always bear in mind that there will always be much more moss in a lawn than that which is visible. This always seems to be the case. So watch that it doesn't become rampant again once your back is turned.

TREATING SUMMER MOSS

MOSS USUALLY STOPS GROWTH IN SUMMER
Because moss usually thrives in wet conditions (some mosses thrive in dry ones), as the lawn surface dries, it dies back because, unlike the grass, it has no root structure to access water deeper in the turf. This is why you should never water a lawn too frequently with small doses. Water heavily at longer intervals (see last year's lawn posts). It gets the water deeper down for the grass roots, but allows the surface to dry.

HIGH NITROGEN FEEDS USUALLY KILL MOSS
After recent rainfall in parts of the UK, lawn recovery can be enhanced by applying a summer feed. Although this can incorporate a mosskiller (ferrous sulphate), it should not be necessary unless the weather (and turf) is very wet for prolonged periods. To give you some indication, I don't think I have ever used a summer lawn feed with mosskiller.

WHICH TYPE OF FEED
The choice is between granular or liquid feeds. (See 'Choosing A Lawn Feed')

Liquids
Liquids are ideal at this time (they can also contain ferrous sulphate mosskiller), because they soak the grass leaves. When wet, the feed is taken into the plant, so starts working almost immediately (granules take about 2 weeks). But there's another benefit. As they dry on the moss, it tends to be killed (due to plasmolysis).

Liquid feeds also have the benefit that they are more controllable, especially if the weather suddenly turns dry. All this was dealt with last year.

WHAT ABOUT THE UNSIGHTLY DEAD MOSS?
Mosskiller instructions and gardening programmes always advise removing the dead moss by raking. But this is hard work and is usually not necessary.
Many believe that this removal prevents the moss re-establishing from spores (moss's equivalent of seeds) left on the ground. This is not true. Only the heavier metal salts (such as mercuric chloride (no longer available)) will kill the spores (it also kills almost all your soil micro-organisms, as well).

Others say removal makes room for air and light to enter the turf. Well. Maybe it does. But lawn grass will almost always grow through it very quickly. And because moss is soft tissue, it soon breaks down in the turf (unless it's a dry summer, or the turf is very acid).

GIVE IT A LIGHT RAKING
I found that a compromise works well. Rake out some. But you don't need to be too thorough. And only do this if it looks unsightly. It's really determined by cosmetics.

JUST A RECAP

So, starting now, follow last year's moss posts through from beginning, just like last year. Otherwise:

• keep zapping moss as soon as visible, any time of year
• rake out some of moss if it looks bad
• apply liquid lawn feed
  

And, don't forget. KEEP NIPPING IT IN THE BUD. YOU WILL BE SURPRISED AT THE RESULTS.