I would use compost instead of lava sand. Absorbs more water than lava sand and has more nutrients. BTW, I take what this guy says with a grain of salt. He can get 'weirdo' on you pretty fast, specially when he babbles why some of his suggestions are better than others because of paramagnetism, etc. By the way, the Dallas Chapter of the Azalea Society recommends using raised beds & replacing the local soil by a special blend designed just for the Metroplex.

Apparently his way works. I truly believe in organic gardening, letting microbes do all the work rather than using chemical fertilizers so I'll listen to this guy and try some of his suggestions.

I've used a blend of lots of compost, cedar flakes (messy, trust me), greensand for iron, and bone meal for raised bed covered with cedar mulch.

I don't really buy into lava sand and its paramaagnetism but i use it with greensand to make it more mixable/spreadable. It really helps. Try spreading greensand alone and it's a pain in the ass.

One guy was really skeptical about greensand but tried it 100lbs per 1000sqft on his lawn and compared to his control lawn. He noticed a big difference so he's convienced but he still doesn't get it.

What's in the 'special' blend? If it has peat moss then it's useless. I see that everywhere whenever i checked out the ingredients in the bag at nursery stores specialized for azeales. I want microbes to do the work. I don't care much for acidic soil. It's not that important as long as microbes do all the work.

I'm not sure I'm following your thinking here; a couple of things you might consider -

Organic plant remains (compost) release organic acids as they decompose, contributing to the acidity of soil. Any time the accumulation of plant remains is greater than the rate of decomposition, an acid condition follows. Your dad was providing a slow release of nutrients and providing the needed acidity for azaleas each time he top dressed with compost. Which is how I feed and care for mine, by the way...my rhododendrons and azaleas have never shown any need for other fertilizers - although that may not be a fair comparision with our PNW acidic soils and ample amounts of mildly acidic rain.

While I don't use a lot of peat, it isn't without value to many gardens. For one thing, it's readily available and somewhat inexpensive. It's true it has no nutritional value, but rhodys and azaleas have very low nutritional requirements compared to most shrubs and peat is the correct PH for acid loving plants. Soil texture is important to the fine surface rooting habit of rhododendron and azalea; since peat has already undergone considerable decomposition when it's purchased, it will last a number of years while maintaining the structure and aeration these plants need to establish themselves. I would always caution a gardener against incorporating large amounts of it into a bed but because it becomes so hard to completely rewet if it dries clear out unless correctly proportioned with native soils or other amendments.

Benefit of peat in non-acid soils is acidification. In hot climates, peat soon melts away, leaving plants in original soil.

"Because of the rapid decomposition of peat, the azaleas must survive in the native soil provided after two growing seasons in Oklahoma. Where good soil drainage does not exist, raised beds are probably the practical answer.

The absence of the peat after two growing seasons further emphasizes the importance of treating the soil with sulfur and/or micronutrients to insure availability of micronutrients to the plants over a much longer time. The length of time such soil treatments remain effective are dependent on the nature of the soil and the quality of the irrigation water. The liberal use of organic or inorganic mulches to moderate moisture and temperature conditions in the plants root zone may further extend the effective time of the soil treatments, especially if the mulches are acid in reaction. For example, redwood and most pine bark are acid and will aid the maintenance of soil acidity, whereas, if the mulches are alkaline, as is the bark from most hardwood trees, the effective time will be shortened."

Here is a link that might be useful: Establishment and Maintenance of Landscape Plants

Previous responses are sound and I would also approach Garrett's recommendations with caution - he does get rather squirrely from time to time.

I'm not sure I understand your reasoning on the soil pH versus microbes. Proper pH is just as important as the biological population of the soils - they need to work together in tandem to provide nutrient and trace element availability. Lack of sufficiently acidic soils will tie up iron, resulting in chorosis. Microbes don't do all the work by themselves.

I have 6 inch tall mounds of exclusively fine Sorghamn Peat, which is mulched with shredded cedar, in which I have my azaleas planted. Next spring I plan on adding two inches of additonal peat and topping that with either pine needle, or shredded pine bark mulch. The peat I use comes in a dry and very compact form. In making the bed, the dry peat gets totally saturated prior to being shoveled to make the bed.

All summer long, I make certain that the azaleas get enough water to keep the beds at the correct moisture level. Nothing else is added, except for an anti fungal spray prior their abundant spring and fall bloom periods.

My evergreen azalea varieties are Snow Krume (sp?) and Red Ruffle. I also have a deciduous 'My Mary' Rhodo doing fine in the same type of bed.

Gardengal,

That's why I used texas greensand which is 20% iron, mostly insoluble but microbes will utilize them for plants. It's true iron get tied up when the soil gets too akailine but soil rich in microbes generally bring pH to around 7, maybe slightly acidic. That's how it's been for millions of years. That's what I used for my St Augustine to keep them green instead of yellowing. I'm pretty sure Azeleas did not rely on peat moss in the first place! :) Isn't their native area forest? I'd imagine that the soil there is pretty rich in microbes, esp in fungi so I'm going to try something called leaf mold or interbay mulch (seemed same to me) where you just leave a thick layer of leaves on the bed every fall and you rely on the fungi to break them down to rich humus rather than bacteria for compost. Interbay mulch requires that you use burlap to cover leaves to retain moisture and protect fungi from elements. I'd think burlap would look funny on the bed so i'm going to cover them a bit with cedar mulch or pine bark.

So yes microbes do a lot of work for you! Peat moss does not definetly help as they are anti microbial! That's why I don't want to use it. Isn't that why I see all those azeales products at home depot, lowes, etc? You gotta feed them with something. Peat moss won't.

katrina,

I use regular corn meal for fungus control on my lawn. Pretty cheap and effective too. I sprinkled around azeales. Hopefully, it should work. Someone i know used on roses and he said it worked very well.