Hi @StephenBrookes,
Yes, you should be able to buy these varieties of citrus; however, suppliers are regional, so I can't link you directly to a product listing. Your best bet would be to head in store and have a look around in the nursery. If these options aren't available in store, have a chat with the team in the nursery; they should be able to contact their suppliers and let you know what is available.
In most parts of Australia, the best time to plant citrus trees is late winter to early spring. At this time, the soil is starting to warm up, frosts are easing, and the tree can put energy into establishing roots before the heat of summer arrives. This timing gives young citrus the best chance to settle in and grow strongly through spring and summer.
Planting outside this window is still possible, but it requires more care. Autumn planting can work well in warm, frost-free areas, as the soil is still warm and roots can establish before winter, but young trees will need protection if unexpected cold snaps occur. Summer planting is not ideal, especially during hot or dry conditions, as heat stress and water loss can slow establishment and damage new growth unless watering and mulching are very well managed. Winter planting in cold or frost-prone areas is best avoided, as cold, wet soil and frost can set young citrus back significantly.
If the issue isn't due to lawn grubs, which sounds likely considering the test, then I'd say it is probably a combination of compaction and drainage issues. Aerating with a pitchfork is a good starting point, as it will allow air to get to the roots and create channels for water to drain through.
You could also use a thatching rake to remove any dead grass from the patches, which will open up space for the existing grass to grow sideways.
An application of lawn fertiliser would also help the existing grass grow laterally to fill in the gaps.
Let me know if you have any further questions.
Jacob
