Gardening Tips for June 2013

One of the most commonly asked questions I get asked is ‘how do I get rid of moss in the lawn’?

I hope this answer will help:

Moss in the lawn can be a major problem, especially during the rainy winter months.

Moss takeover is a result of a series of garden problems.  Identifying and solving these problems promptly will discourage moss growth in the future.

Moss spores, exist naturally in the garden and only becomes a problem when the lawn can no longer compete with it.  A weakened or stressed lawn can be due to a number of causes, low or unbalanced soil fertility, compacted or wet soils, and heavy shade acidic soil.

A thick thatch layer (thatch is a layer of dead grass that has not decomposed; it inhibits water, air and fertilizer penetration into the root area) these problems can be corrected chemically and by hard manual labour scarification (vigorous raking).  Try pruning nearby branches to allow even a little more light in.  One way to help eliminate moss is to first rake as much as possible out with a spring tine rake but you will not get it all.

Then apply your preferred iron sulphate based moss killer to the moss that remains after raking.   The moss will now be thin enough to allow better penetration of the moss killer; this method will get about 90% of the moss.  Moss killers combined with a fertiliser are beneficial where grass vigour is low.  Apply moss killers, either by hand or with a push-along spreader but be careful not to apply lawn sand (ferrous sulphate mixed with a carrier) at too high a rate as this can blacken and kill the grass as well as the moss.  Apply lawn moss killers in fine weather.  Some require watering after 48 hours if there has been no rain. Check the packaging for details.  Also, take care while spreading near the pavement and the house to avoid staining the cement.

If you want to apply ferrous sulphate (sulphate of iron) before raking it. It is best to do this 7 to 14 days before raking.   A light high grass cutting with the mower beforehand will help, because ferrous sulphate acidifies the soil you MUST use it evenly over the whole lawn otherwise you will create pH changes which may affect grass growth and may even increase moss growth in future.  The lawn should stay dry for approximately forty eight hours after applying the moss killer, and then a thorough watering is required. After seven to ten days the moss will begin to turn black, at which time you should hand-rake or dethatch your lawn.  This will allow the grass to grow again in areas previously covered by moss.  If bare or thin patches result from moss removal, reseed the area with a grass seed mixture containing a high percentage of perennial rye grass seed. A thick, healthy lawn does not allow room for moss to become established.

It is best to rake out the moss on a dry day when the grass is noticeably growing.  Mow the lawn reasonably close before hand to better expose the moss and reduce resistance on the rake.

Try Maintain a good fertilizing and watering routine. For the first feeding, a well-balanced lawn food, such as Maxi crop Moss killer and Lawn Tonic, Westland Lawn Feed, Weed and Moss killer, Scot Granular lawn Feed Weed and Moss Control, or Gouldings Lawn Feed Weed Moss Killer.

Later in the summer, a higher-nitrogen fertilizer can be applied to stimulate green growth, but please keep in mind that while fertilizing is important, you should not over fertilize your lawn during dry periods, less frequent but longer periods of watering will produce deeper and healthier roots.

Try to improve compacted or wet soils. Lawn roots will thrive in healthy soil that drains well and has plenty of organic matter.  Poor soil will not drain well and this will only encourage moss growth. To correct compacted soil, aeration is highly recommended. Aeration is the removal of soil plugs; this allows air to penetrate directly to the root zone. The added oxygen encourages soil microbes to break down organic matter, such as thatch. The holes also allow water to penetrate more easily.