South Australia - 16th July 2001

• Soil temperature in the Campbell vegetable patch was 11⁰C all last week and in the many containers I have, a remarkably consistent 9.5⁰C at 8am each day. So what you may ask?
• Well soil temperature is critical at this time of year and probably all year, but right now the containers are getting both colder and warmer during the day than the soil, that stays about the same all day and night. The media (since it is not soil) in the containers warms to 15⁰C by early afternoon.
• This means that adding controlled release fertilizers like Osmocote®, Nutricote™ and Phostogen™ to your soil is of limited benefit at present, since the prill or small round granule is formulated to release the nutrient at a temperature above 12⁰C. You can add it of course, but it will not release nutrient and it sits waiting for spring temperatures.
• On the other hand adding controlled release prills or what some call ‘slow release’ (and they certainly are that in winter), is most beneficial, since they are taken up by your plants, unless the plants themselves are not in a state of growth, like Hydrangeas and deciduous fruit trees at present.
• One of the best approaches to feeding your flowering bedding plants, like pansies and poppies, in this cool weather is to foliar spray them with a water soluble nutrient, such as Vital®, Aquasol™ or Thrive™. That is taken up immediately and you will see the response, within days.
• Probably the only way to get a green smile from your Kikuyu lawn in this month is to apply nitrogen from a water soluble source, in the form of urea or one of the high nitrogen water soluble fertilizers. You could of course just let it stay dormant.