Summer 2019 - Dry for some
This spring has already started dry and the current lack of rain in many parts may cause issues so please take note.
Do's and Don'ts for Dry Weather
When we mean dry we don't mean clear skies, warm, hot or sunny. We mean no moisture in the soil and in particular around the grass roots. Therefore, it could be the warmest dryest week of the year but if you have had a couple of inches of rain the previous week then the soil is not dry and all is well. If you've had little or no rain for weeks then you need to check the soil for moisture.
What is adequate soil moisture: We judge this to be moisture within the top two to three inches of soil that allows the grass to remain green, springy and growing well. Therefore if the grass starts going dull, doesn’t partially spring back up when you walk on it or growth slows when it is warm or dry then it would be safe to assume there is little moisture in the soil. Opening up the lawn with the corner of a spade or bulb planter to a depth of 2 to 3 inches will enable you to observe moist or dry soil.
Doing the right thing
If it's dry your objectives are to:
- Preserve moisture
- Prevent evaporation
- Damage the grass as little as possible
Perhaps the most important lawn care duty to preserve moisture. You need to mow as high as possible:
- Grass is 85% water - removing grass therefore removes water
- Long grass creates a barrier between dry sun and wind and moist soil
- Long grass keeps the soil cool thus reducing evaporation
- Long grass traps more dew when there are low night time temperatures giving the lawn a daily drink
If the mower instructions allow mow with the box off. If you have set the mower to just take the top off then these fine clippings will disappear in 24 hours returning valuable moisture to the lawn. CAUTION: If weeds are seeding (flowering is not a problem) then best keep the box on.
You also need to mow with sharp blades to minimise loss of water through jagged cuts with blunt blades.
This is important whilst there is still adequate ground moisture as most Lawnsmith fertilisers contain potassium. This is vital for the moisture control functions of the plant. Our fertilisers have an application range on the bag e.g. 25 to 35 grams per square metre. Use the lower end during low moisture levels and the higher end when conditions are optimal with good moisture levels.
However, once the soil dries the fertiliser cannot be taken up by the grass due to lack of water to transport it to the roots. This may stress the grass or even cause grass burn so wait for rain or irrigate deeply beforehand. It is fairly pointless to fertilise a dry lawn as it won't do any good! This applies to ALL types of fertiliser.
- The weed killer works best when growth is good
- The grass is stressed in drought conditions and may be damaged by the weed killer
- As soon as it rains you'll be over run with weeds which means treating before rain is a waste of time
Moss Killer and Ferrous Sulphate
These can be quite aggressive in dry conditions so if you need to kill moss but consider things to be on the dry side wait for rain or soak the lawn before hand.
This should be with solid spikes only - aerator sandals and the rolling aerator are ideal. If things are starting to firm up (older lawns will already be firming) then spikes will only penetrate a little. Don’t worry, any surface spiking (even 1cm) will help showers to penetrate. Do not hollow tine as this increases evaporation.
Raking and Scarifying
If you haven’t done it yet consider postponing until after rain or until the next season if things are already starting to dry. If you are able to water then carry on as planned.
The choice is yours but if you do water you must water deeply - at least an hour a week in any one place. Shallow watering will:
- Cause shallow rooting
- Promote weeds
- Promote the weed grass ‘annual meadow grass’
Read more on Watering the Lawn
Turfing, Seeding or Over seeding
This will require extra water in dry weather. Consider saturating the area prior to seeding or turfing to build up a reservoir of moisture.
If seeding it may be worth doing this: Heavily water the area before seeding, seed, then cover with a sheet of polythene pinned in place with bricks. Remove it once green shoots are an inch high then start watering. Very large poly sheets can be obtained cheaply from builders merchants etc.
If you've done the wrong thing!
Help I’ve burned the lawn!
Join the club as we’ve all done it at sometime.....
Lawn or grass burn occurs in two ways from Fertiliser, Moss Killer and Liquid Products including Weed Killer:
- Fertiliser or chemical sits on the grass leaf burning (drying or desiccating) it. This can occur very readily with fine powdered products even in good conditions and normally requires watering in within a few days to stop the burn risk. These products are usually 'Weed and Feed' and '4 in 1' type products. It can also occur with soluble or liquid products if moisture levels are very low. The damage is similar in both cases and is usually observed as shrivelled or blackened grass leaves. This will not happen with any of the Lawnsmith granular products.
- All dry powdered or granular fertilisers (other than 100% coated or organic) will eventually dissolve into the soil. If the soil has insufficient moisture to dilute it adequately the fertiliser forms a strong solution in the soil causing moisture to move from the plant into the soil by osmosis. Very low moisture levels with a normal rate application of fertiliser will cause the grass to start to turn a bluey colour but should not burn. However, if the dose has been excessive then brown patches appear as the grass turns brown and possibly dies. This happens for two reasons:
- There is insufficient soil moisture for the amount of fertiliser applied
- Too much fertiliser has been applied either accidentally (usually due to hand spreading) or possibly due to poor measurements, inexperience or faulty equipment.
Of course, if too much is applied AND moisture levels are very low then serious damage can occur.
The remedy: As you cannot remove the fertiliser or chemical you need to dilute it by watering. This will reverse the burning action and quite often, within four weeks, no lasting damage will be observed.
Caution: It may be the case that not all your fertiliser has dissolved into the soil and some is still waiting to be ‘activated’. This means when you start watering you will activate it, and, if you water insufficiently this will also start to burn causing more brown patches not fewer!
How to water: Water with a garden sprinkler for at least an hour in any one location. Depending on how badly the initial burn is, and, if there is no rain, you will need to do this every day for 3 to 7 days because sprinklers do not put out that much water compared to a good down pour. More water is always best as it is easier to water the lawn than it is to repair it!
Yippee....it's started raining
Now is the time to get your lawn looking green again so read 'Reparing Burnt Summer Lawns'