Fertiliser for Perth lawns is about having the right NPK ratios and the necessary micro elements for sandy soil. It is also about feeding at the right time. Now that the sun is shining and soil temperature is starting to rise, that’s great for us Lawn Lovers. Why? Our lawns in WA are warm season. This means they grow when it’s warm and are dormant when it’s cold. That’s why you see yellowing and mow less, just like cold blooded reptiles and insects.
So like cold blooded animals and insects that come out of hibernation and the one thing on their mind is food, so to does your grass. It is hungry. The photosynthetic process is kicking in and the plant is looking for nutrition. Because Perth is located on sand, the nutrition available is low as it hasn’t got the ability to hold onto it like clay and loam do.
To get your lawn going and provide it with the food (nutrition) it needs you to give it a feed of Nitrogen (N) for colour and leaf growth. Remembering from previous posts, growth equals leaf surface area is increased for greater photosynthesis. Phosphorous (P) for root development. Potassium (K) for strengthening the cells of the plant. Do not use a fertiliser with a high K ratio. Potassium is also for fruiting and flowering, and you don’t want your lawn seeding (flowering) to much! That is why it is best to stick to a lawn fertiliser for Perth lawns.
So that’s the NPK covered as your Macro elements, then we need the Micro or trace elements. Most quality fertilisers will contain Iron, manganese, magnesium, copper, zinc, boron and molybdenum. The percentages of these trace elements are small but vital for grass health. Your lawn can only perform as good as it’s least available element.
Additionally, you may have chlorosis, a yellowing of the leaves. This is the first sign you have a trace element deficiency and more often than not it will be Iron or Manganese. Iron is important for energy production within the plant and assists with nitrate and sulfate reduction in plants. Manganese is involved in many physiological processes in plants but mainly photosynthesis. with these two elements you must apply them together as each one helps the plant absorb the other.
The best fertiliser for Perth lawns will have all the macros and micros and you need. In cases of severe deficiency you will be well advised to apply foliage applications of iron and manganese. Ideally, 250 gm of iron sulphate and 250 gm of manganese sulphate in 20 litres of water for every 100m2 you have. A word of WARNING though. You must take extreme care when applying iron in any form as it will stain. If you have limestone pavers or concrete, or any decorative concrete be ware NOT to get it on these surfaces, again IT WILL STAIN. When applying a granulated or dry fertiliser, ensure your concrete or paving is dry when applying , then if you get some product on these surface simply blow or sweep it off.
If you are looking for a granular fertiliser with all the right micros and macros for Perth sand use our own Knights Coastal Special Mix.
When applying a dry fertiliser, it is best to water them in after application so apply on your watering day. Fertilisers with higher, more soluble nitrogen, such as Sulphate of Ammonia tends to start to dissolve easily. When not watering in it will burn the leaves. When you apply a foliar fertiliser through a sprayer, do not water in as it needs to dry on the leaves as it is absorbed through them.
Rates will depend on your lawns condition but generally it is best to apply 10kg/100m2 for the initial fertilise and then apply smaller amounts more often, say 5 kg/100m2 every 6 weeks. This will ensure you have nutrients in the soil for the plant to use without creating maximum growth. If you remember in the first paragraph we mentioned sand, sand hold very little fertiliser nutrients, hence fertilise more often.