Following the vigourous debate incurred in the 'Rainforest Plants and Fertilisers' thread, I resolved to conduct an experiment of my own. Of the 4 grevillea I purchased at Rocky markets this morning, two now reside in an extremely hostile position alongside Syzygium Cascade, Pandorea (Jasminoides and Pandorana) and several exotics such as Ixora. I say hostile for two reasons :

- the Rocky sun has already turned several Ixora to charcoal, and even the lillipillies have looked a bit secondhand at times
- there is residual fertiliser in the soil, both from the previous occupants *bizarre* collection of weedy exotics and my own bumbling efforts

The two sacrificial lambs are 'Ned Kelly' and 'Coconut Ice' - both share a common parentage, and both can be found at nurseries up and down the East Coast. I couldnt bring myself to consign my other 2 purchases to (almost) certain death, so these will have to suffice. From the ASGAP site:

'Grevillea "Ned Kelly" is one of several popular hybrids which have a similar parentage. It is a cross between the Queensland species G.banksii and the Western Australian species G.bipinnatifida. Others with these same parents include G."Robyn Gordon" (probably the best known and most popular of all Grevillea cultivars), G."Superb" and G."Coconut Ice". All are bushy, medium shrubs with large racemes of reddish flowers.' ( http://farrer.riv.csu.edu.au/ASGAP/g-nedke1.html )

I'll give them two weeks and some seaweed emulsion to bed in, then begin applying the following at monthly intervals:

1. Blood and Bone - should be fine
2. Organic Xtra - apparently 'suitable for natives' : hope so. Hasnt hurt my lillipillies, but they arent proteas ..
3. Osmocote Plus (Garden Beds) - NPK 16:*4.4*:10 - if this doesnt kill them, I will have to eat my words and a large does of humble pie.

3.5 months from late Jan will put us into May - still warm enough in Rocky for the sun to force the Osmocote to begin releasing its payload. Even if we have to wait until August ('Spring' happened on a Wednesday in Rocky last year ..), it wont be long before we see a result.

Why the gradual introduction of a high NPK fertliser ? Firstly, I dont think its overly fair to the Grevillea to just hit them with this straight up (admittedly, the amount of residual fertiliser may make this a moot point), and I'd also like to condition my lillipillies - I dont want to lose them as a side-effect. Those who havent seen 'Cascade' wont know what they are missing out on - highly reccomended.

Scientifically, this is a woeful experiment. We dont have anything resembling lab conditions, but it does conform to the pattern where a newbie gardener sticks a Proteaceae in with their other plants, then proceeds to feed and water it to death. I am fortunate to have superb drainage on my side, but I remain pessimistic re the chances of the two candidates. My nurseryman has assured me that Osmocote will see them begin to burn from the tips, and that they will be on borrowed time from that point forward. Time will tell.

For those who see this as cruelty to unsuspecting plant life, I can assure you that its not my intention. The only way that we will ever find out if 'home truths' apply in our own patches of dirt is to experiment, both with plant choice and cultivation techniques. Most of the plants in my garden do it pretty tough, but the 10 or so Grevillea enjoying their own bed at the front appear very happy indeed : all I have to do now is stop the parrots monopolising their flowers.

Happy Trails,

Artie

keep us posted artie

You know I never though about it till I read that thread, tell me if what kind of fertlizer would I need to use near a G.robusta to help with its demise as Organic Extra is certainly not working. Brand name if possible Thanks Artie. Cheers....MM.

Like you say, it's probably a good idea to wait before applying anything. With Osmocote NPK 16:*4.4*:10 on its own, I think the high nitrogen would actually promote growth, so yes, it will be interesting to see what happens.

I'd be leaning towards Ned Kelly coming through it O.K.

MM, I think we both know that little things like fertiliser, bushfires and environmental degradation wont put a silky oak out of *your* misery :)

I often have to restrain myself when I see Robusta on sale at church fetes etc - it should come with a large warning for people on suburban blocks, IMO - great in the right setting, but just too big for the average block.

Into the trunk of the tree you need to drill a hole 1/2" diameter using a fairly long bit or drill. (Brace & bit is ideal) This hole can be fairly low to the ground but must be deep enough to reach the centre of the trunk or further.

From your hardware store purchase 30cm length of 1/2" copper pipe and insert this into the hole in the trunk. Then wait - as the copper will kill the tree.

You are right robert we have a steering wheel column through one of our gum trees put there about 25 yrs ago when the big boys from next door were little, there was a star picket growing through another, and we have also found other odd bits of metal inbedded into the tree trunks on our block so hubby and I have had to look very carefully before he cut down the 23 trees from here..Thanks for the advice ........Cheers..MM.

I have Grevillea olivaceae and it's growing very successfully. I've had to prune it a few times, otherwise it would have taken over! No problem with yellowing leaves, but I have another little groundcover grevillea very close by and it's miserable - growing poorly and yellowing.

As I've said in another posting, the hybrids with G. banksii parentage are also very successful with no yellowing.

Rainforest proteaceae such as North Qld Tree Waratah was a little prone to yellowing when small but now has no problem.

Cheers,
Frank

Can you give us an update on their health - thus far.

I'm still tipping the G. Ned Kelly to be the winner and actually show no effects at all.

Update?
~Onion

Living in Northern California, you may not know that much of Queensland has recently been deluged (a cyclone and a couple of other low-pressure systems). I did apply another round of Osmocote shortly before the 'flood', but I believe that this was washed straight past the roots within days (hours ?) of application.

As I mentioned in my initial post, my aim was always to see what happened to the Grevilleas *without* harming the other plantings, so its probably back to the same dosage as the last batch in about a week or two. It would give me little satisfaction to have a Grevillea survive and one of my prize Syzygium Cascades keel over, as unlikely as that seems ...

Cheers,

Artie

Here in northern California we've had a month and a half of unusually rainy weather, too. I've resorted to putting an umbrella over my rain-intollerant trough plants!

Best wishes,
~Onion

I do have the same problem with yellowing of proteaceae. Have a look at the pdf file linked below. The last sentence of the first paragraph and first sentence of the second paragraph under 'Interpreting Soil Data' explains what I understand the situation to be in Toowoomba and the Downs. The iron is there in the soil, but alkaline soils make that iron less available to the plant. Using iron chelates is a quick fix but when I tried that, it was necessary to continually reapply it because the alkalinity just overpowered the chelates before long. That gets expensive. Others have used sulphur and iron sulphate to try to adjust the pH and therefore improve iron availability, but that takes longer to be effective.

It occurred to me recently that maybe I should just try adding some vinegar to any water I use on the sensitive plants (not any lately). The town water is quite alkaline and worsens the problem. Adding some vinegar should in theory overcome this I would think. I have been meaning to follow this up by checking how much vinegar to add with some pH indicator test - I'm thinking the kit that gets used for checking swimming pool pH. Vinegar is cheap and I can't imagine much would be needed.

Cheers,
Frank

I'm still waiting for the results of this test. None of my test grevilleas have suffered from similar applications of no-name brand high P fertilizer. Indeed they are looking better and better.

Eremophilas also seem to enjoy more P.

I will be applying the Osmocote very soon, as I am also anxious to see how it goes. I'm a little frustrated with this particular bed, as the lillipillies and Pandorea vines dont seem to be performing as well as they have in other parts of the garden. Sloping beds have superb drainage, but I believe that also leaches a lot of the nutrients from the soil.

My bed at the front was also annoying me with its propensity for killing young Grevilleas planted in a certain spot at the rear, so I replaced the last victim with a dwarf Melaleuca about 6 weeks ago. The little fellow looks so happy that I am tempted to plant them in all future garden troublespots - at $2.50 ea from the local markets, its hard to go wrong :)

Cheers,

Artie

Just wanted to record that the Osmocote was applied a week ago and I havent seen any sign of distress on the part of the grevilleas as yet. Some of the nearby Gardenia Radicans are looking a little yellow, but I suspect that may be a nitrogen issue - they havent had a whole lot of TLC in the last 10 or so months. When I come to think of it, that bed has really been a tough place for every plant in it. The lillipillies (Syzygium Cascade) and the large-leafed Ixora have powered, but the rest of it seems to be just hanging in there. Darwin would have been proud of the Rocky sun's ability to select the 'fittest' ....

Cheers,

Artie

(yes, I'm making this up as I go along, but I think the general point is valid)

It is my sincere hope that the drainage in my Grevillea beds is sufficiently good that I wont lose anything to root rot, but its posts like yours that make me wish I had used crushed sandstone instead of simply mixing sand into the existing soil. Don Burke's book always comes back to haunt me when I look over at that front bed.

Cheers,

Artie

The two lab rats ('Coconut Ice' and 'Ned Kelly') are going strong a month after the Osmocote application. I cant say whether they are still actively growing at the moment (daytime temps still in the mid-20s), but there is no sign of yellowing at the tips etc. despite a couple of downpours since the fertiliser application. This doesnt *prove* that these tropical grevilleas can handle high Phosphorus loadings over time (it may have been leached away by the rain), but it is encouraging nonetheless. Will repeat the dose in early Spring and report back.

Cheers,

Artie

I tipped that Ned Kelly would take all you give and still come out loving it. I may be right!