"Sue" writes:
Rainfall - under 300mm per year.
Temp Ave. Summer 35 + Winter 25 - Summer is about 8 months or

I guess you are going to plant more than palms alone, e.g., annuals or
vegetables, too? Then when compost or manure is in short supply, rather
than spreading what little you have throughout the garden bed and having
it make very little improvement, as you plant each annual you can dig the
hole a little deeper and put a trowelful of compost in the bottom before
dropping the plant in. Add some of those polymer water crystals to the
hole, also, as they absorb water and release it slowly to the plant. The
roots of small annuals don't go very deep, so as far as the plant will
be concerned, it will be nearly as good as a well-composted garden bed.
Except it will dry out a lot faster. Would any of the hardier vegetables
do okay in Summer under shadecloth? Drip watering would be most efficient.

Four garden stakes with shade cloth wrapped around at least the upper half
and folded over to cover in the top should offer sun protection to seedling
trees.
--
John Savage (for email, replace "ks" with "k" and delete "n")