Looking forward to answers on this as well. Hopefully there is an organic equivalent to the answers you will receive as I am expecting Texas-Weed to come here and offer his advice on using a Lesco slow release 39-0-0 synthetic fertilizer.

What are the natural materials to add phosphorus and potassium to the lawn during this time?

Also is it true I can add Gypsum to lower the pH of the soil? I thought Gypsum and Lime share inverse relationships to one another where Lime raises pH and Gypsum lowers it.

Bermuda grass wouldn't do well here, but I know there's a Bermuda Bible here.

You still can apply herbicide on current weeds now if you wish or simply mow them down to keep them from producing seeds. Just make sure to follow the label very carefully. For preventing weeds, pre em application in feb and october will do the trick. One time application of 15-5-10 fertilizer is fine (fall is probably best time for it) and rest of the year go with Lesco 39-0-0.

Gypsum is used for sodic soil to get rid of sodium ion in the soil. Lime is used for very acidic soil. Core aerating first is probably best way to get these into the ground to make a difference.

pkapeck - there have been plenty of threads over organic program for bermuda. Do some search for it. It's hard for me to tell you anything as you live in Florida and I don't know what's available. Tx Weed lives in Texas and he probably won't know either what's widely available in Florida. For potassium, I use greensand. Kelp meal will provide that as well. Phosphorus - in organic fertilizer like alfalfa pellets, soybean meal, etc. Bone meal should have a lot of it. There are more. The real issue is the availability of these products in your area. Even leaves, mulches, etc will have these. If you want bermuda to stay dark green and dense, lesco 39-0-0 is much more economical. I've heard of others applying soybean meal every month and it has gotten a lot more expensive...

Thanks Lou_lidloather. I was using alfalfa and UCG as well as soybean meal. I just assumed they were mainly a nitrogen source with no P or K values. Bone meal is available here but I'm not sure where to buy 50# bags of it. Home Depot only carries the small 5# bags and they aren't cheap something like $5.97 or $7.79 per bag. I think the only place for greensand (which I have a small bag that I generally just used for mixing small amounts of soil for my potted plants) was at a mom and pop garden center that is 2x the price of the big box stores and generally don't carry what I need.

Any idea what I can use cheap and easy to lower the pH of the sandy soil.

So I listened to him as he told me to wait until late February and Early May (first week of May) and apply

-Pre-emergent (1st)
-10-10-10 (2nd)
-Iodine (?)
-Lime

He said apply all of those at the same time but not mixed together (one at a time).

I was hopping to follow him exactly but my lawn is getting full of weeds and crab grass. Should I still ignore? Wait for it to be end of February.

If you already have spring weeds, then it is too late for preemergent. I would be surprised if you have crab grass already. Can you take a picture and post it?

"Iodine" is probably Ironite to supply iron to the soil/sand.

Unless you are going to use organic fertilizer, do not fertilize until you have mowed real bermuda grass for the second time. If you fertilize before that you will only be fertilizing the weeds. However if you are going to use organic fertilizer, then you can probably fertilize pretty soon. I fertilize about 3 full weeks prior to the "last frost" date. For me it happens to fall on Washington's Birthday.

You didn't say whether the builder used sod or seed, but typical Georgia would be sod-Tifway 419. Since it is dormant you can "paint" the weeds with round up. It won't hurt the Bermuda, but will kill the weeds. I would put down a pre-emergent right now. I use AMAZE by Greenlight (as long as it wasn't seeded). This will prevent future weed seeds from germinating. When it warms up, follow the Bermuda Bible. I use the Leso 39-0-0 every 30 days during the growing season (per Texas-Weed), and cut at an inch or less using a reel mower...this maybe too much info.

Builder used SOD ...

So far

-Pre-emergent (1st)
==> Done

-10-10-10 (2nd)

== Just bought it but I haven't applied it. Should I wait for the Grass to appear as waking up from dormant or just do it now? So far I mowed once over the weed covered lawn (just yesterday)

-I also bought two bags of the weed killer (vigoro lawn weed control) which I plan to apply after watering or (rain hopefully ;-))
today or tomorrow

-Iodine (?)
=I haven't found it but will look for it.

-Lime

I got two bags of those...

well, hope I'm doing the right thing :) .. if I fail, I am getting my lawn full of Crab grass because they don't seems to require whole lot to grow .... ha ha

-I also bought two bags of the weed killer (vigoro lawn weed control) which I plan to apply after watering or (rain hopefully ;-))
today or tomorrow

You're the guy who the anti-lawn-nazis hold up as an example of us lawn aficionados killing the environment through their lawns. All I can say is please, SLOW DOWN. You are wasting your money, what you're doing won't work the way you expect, and, as the anti-lawn-nazis say, dumping poison on the soil.

The advice above was to spot spray the individual weeds, not cover the ground with herbicide.

You will never find iodine for your yard. Read above and/or go back to the guy you talked to first.

If you have not read the Bermuda Bible, and I suspect you have not, please read it. My link is to the latest version published a few days ago.

Everything you want to know is in the Bermuda Bible