I have a Page orange on a Cleo rootstock in my orchard that I'm having a problem with. Of the nine citrus that I have in the ground it is easily the palest in leaf color of them all which has me wondering if maybe the pH of its soil is too low? Most of what I have is on trifoliate with a couple of unknowns. Everything is fertilized and watered the same way and except for the Page it all has good color. I haven't tested the soil it's in, but I know I've never limed that particular spot and all of the unammended soil around here is somewhat acid to begin with plus my usual fertilizing regimen runs to the acid. Should I sweeten its soil?

.....Alan.

Cleo, like all true genus citrus root systems, would like a higher pH than does Poncirus or its hybrids. Anything in the 6's should be ok, with 6.5 being ideal. On the other hand, Poncirus and its hybrids would prefer the 5.5-6.0 range.

Dr. Manners, there was a post the other day about the pH of Florida soils. Generally(ball park), are Florida's soil acidic or basic? -Millet

In the main citrus producing regions, the pH tends to be acidic. Here on the sandy central Ridge, 4.5-5.0 would be about normal for virgin soils. Our well water, however, comes from a limestone-based aquifer, so the pH of irrigated soils tends to rise, particularly since our light sands have very little buffering capacity. Also, nearly all growers use dolomite on these soils, regularly, to bring the pH up to a better level for citrus. Since most of the industry is now on 'Swingle' roots, 5.5-6.0 is considered ideal.

On the east coast (Indian River area) and in far southwest Florida, where most of the newer groves are located, again the "average" soil pH will be acidic; however, there are areas with quite a lot of shell (in the case of the east coast) or limestone bedrock (in the SW) which make specific areas alkaline (up to about 8.1). Often in these areas, it varies wildly every few acres or even less. So pH management becomes a challenge.

Thank you - Millet