Banksia S. Leaf Browning?

[Luke]

hey iv had this banksia s. for a couple months and in the last week or so some of the leaves have been browning (mainly at the top). >> Other parts a growing very well.. its in a highly composted (chicken poo, cacti mix, perlite) soil that has good drainage.. it gets watered every morning, some arvos.. morning sun (7:00 to 11:00)
i did put an 'all-round' slow release fert on about 3 weeks ago, since then iv learnt that natives like 'native' ferts.... could that be it????


thanks in advance for any tips, info, ideas.....

luke

[Luke]

all the mighty hot days we have been having here is most likely the problem... and now, after another high 30's swelteringly hot day.... we get the storm... WooooHoooo

luke

[shibui]

I would not discount the fertiliser. Banksias are VERY susceptible to phosphate if they have not had much before and have developed proteoid roots - tip the plant out of the pot and look for 'starburst' clusters of short, fine roots around the edge of the potting mix if you want to see them. They can shed the proteoid roots and recover from mild cases but will look sick like this for a while. if it recovers it should be able to tolerate fertiliser better as long as it gets a constant supply and doesn't grow those roots again.
Hopefully it was just the hot weather or a mild case of phosphate poisoning so it can recover.