Q.Why red grapefruit tree has no blossoms
Why did my red grapefruit tree have no blossoms this year? The tree is 4-5 years old. First couple of years heaps of blossoms and lots of fruit. 2013 only a couple of fruit and nothing last year – just a few flowers that came to nothing. I have been fertilizing, as soil is almost pure sand and making sure it gets watered every 3 days through summer. Coincidentally, dwarf mango also did not flower this year – no flowers at all.

The foliage on dwarf mango looks completely normal it just didn't get any flower heads and no sign of insects. The grapefruit did have a lot of pests the last 2 years. Weird beetle type creatures with hard shells about one centimetre long with a x on their back. I tried to collect them all off the branches and dispose in bin. They were concentrated on the tips. Is there anything I can spay to stop them coming back this year? They didn't seem to be anywhere else in the garden.

Do the trees otherwise look healthy - particularly the foliage? I was just wondering if there was any sign of disease or insect infestations, which would affect flowering and fruit set. Do you see anything unusual at all?
I know that Perth typically has mild winters but have the winters been colder than usual these past few years? Have the trees experienced a frost?
I would recommend that you get a soil test to be sure that your fruit trees are getting the right amount of nutrients.
For more information on the care of grapefruit trees, please visit the following link:
https://www.gardeningknowhow.com/edible/fruits/grapefruit/growing-grapefruit.htm
https://www.gardeningknowhow.com/edible/fruits/grapefruit/grapefruit-tree-not-producing.htm