Julio,

5.3 is very low for olives. Where are you where temperatures go below 25 degrees?

Sorry for not mentioning I was in northern Mississippi. I posted a description of my experiment in growing olives in n mississippi in October in this same fruit tree forum with the last post being on Dec 10th, 2007 (p 4 now). Right now they are being grown mainly in California, in Texas, and possibly parts of Florida.

I have two problems, the first described in my post in October being the low temperatures here. It has gotton down to 10 deg F most years in the last 10 but there are not many hours below the 25 deg F per year. This year it has gone down to 28-30 deg about five times and the last cold snap a few days ago went down to 14 deg F. Today and tomorrow it is in the 70s. So I made covers for the trees to protect them when it got below 25 deg since the seedlings are new. Mature trees can handle colder weather as documented in a couple of references I quoted (near zero deg F in parts of California in 1990). The Mission trees I planted are supposedly hardy to 8 deg F, the most hardy of olives. It has gotten to -13 deg F here in 1954 which may be a once in a hundred year event. I know the olives will like the hot summers here better. So far I covered them for 3 days in a row only once. They look fine and even have new growth since planting in October 2006.

My second problem is that I probably should have done it right, doing a soil analysis, determining how much lime to add, then using a plow to disk a 10 ft wide 2 ft deep area, plowing in the lime before planting. While I dug a fairly large hole and mixed in 2 handfulls of ag lime, I probably need to add 12 pounds or so of lime per tree if I am correct in interpreting the soil analysis. My question is whether I can add it over time to the soil surface in a 10x10 area around each tree.

The limestone gravel would NOT be replacement for azomite but would actually be one for the agricultural lime, though way too slow in acting, possibly on the order of decades.

Ag limestone is reputed to eventually leach its effect to rooting depths though fairly slowly, maybe a year or two if I recall correctly. It is not exactly clear to me how this happens in that calcium carbonate (and especially dolomite, calcium-magnesium carbonate) is not very soluble in the neutral water that is produced by reacion with acidic soil water near the ground surface. The fact that you have already treated the planting hole gives you a fair amount of leeway one would guess, to have time for surface applied lime to leach to root depth.

It is hard to imagine that any but very sandy soils in Mississippi would benefit greatly from azomite, a type of clay it says in the sales literature. Does MSU highly recommend trace metal fertilization on your soil type? On the leached sands on the south and southeast any montmorillonite clay would be a nice addition, but the sellers tout the microelement content of theirs. This type of clay has high cation exchange capacity (cations are held between the "plates" of this layered clay) so maybe their particular deposit does have a good suite of nutrient metals. But so does kelp for that matter.

Also, these amendments will be very helpful for the first 2 years, but a good mulching program will do wonders to help bring your soil closer to balance. Do your lime or what ever first, then Mulch Mulch Mulch
It's simple and it simply works

I incorrectly stated in my last post my olive trees were planted in Oct 2006. Actually it was Oct 2007.

I need to see if I can get any more info from MSU who did the soil test about whether I apply all the ag lime at the same time or not. Gonebananas is right about the limestone gravel dissolving slowly (a large pile has been in my driveway for several years) and it sounds like the ag lime idea if done correctly should eventually get the surrounding soil to the correct PH. If I used the limestone gravel and spread it around the trees it would interfere with any mulch addition so its probably not a good idea.

The idea for the azomite came from the website of Santa Cruz olive tree nursery where I bought the trees but I suppose that is less important than the soil PH. They soil here is more clay than sand and doesn't drain as well as it should, another potential problem. Thats why I added compost to an oversize hole when I planted the trees. I was going to add sand but several people told me that would make the soil harder, not softer.

MSU and no one else I've found around here is familiar with olives, as they are not being grown by anyone else in Mississippi to my knowledge. Closest place near Austin, Texas. Most people told me that I shouldn't try them in zone 7 and a grower I talked to over the phone advised me to only plant the Mission variety due to the cold temperatures here. A professor at MSU told me that they would start an olive trial next year after I called and told them I have 21 growing here. I'll probably add another 20 next fall.

Softmentor, what kind of mulching would you suggest. Right now I have applied pine needles around the trees to keep competition away. What about spreading more compost around each tree over a larger area (10'x10' per tree). I'm not as knowledgeable about gardening as many on this forum, as I've generally planted trees (pines,oaks,etc.) and just left them alone.

Thanks for everyone's advice, as I've gotten most of the information on planting here rather than from the sellers or local sources.

Julio,

I guess the biggest concern is the humidity during the summer. Olive trees are not going to like that. I believe your winters have been milder than in the past and summer rain has been non-existent. That type of weather maybe be a permanent change, I don't know, but in the meantime, you should prepare for a lot of winter damage, meaning complete die back to the ground. And then re-growth during the summer. Also olives need calcium for proper fruit development. I have been to many groves in France and Italy where the trees are growing in limestone. So I am not sure about olives as a commercial crop in Mississippi. Maybe as a novelty.

To grow off a new seedling 18-46-0 some N needed with superphospate 0-46-0 is used in blending fertilizer 18-46-0 is best known for popup fertilizer but great on seedling more roots larger trunks and new growth have larger diameter. 0-46-0 mix in planting soil has no N so no salt for roots being its super it not last in soil long be tied up soon. Soil appilyed lime has little use good only for shallow roots like grass vegatables. Powered lime quick fix for ph. A ton compost give out 500 lbs lime un less from acid loving plants.