Eazine: Despite the fact that many, many people do it, Spring is NOT the best time to do a lawn renovation. Very late summer is the time where you'll get the best results. You may want to consider improving the soil this Spring and Summer, and doing a renovation in very late Summer. There are very few organic alternatives to RoundUp (glyophosphate) for killing large areas of lawn. High-potency vinegar (15-25%) is OK for spot treatments (kills everything), but other "alternative" solutions that you may find (bleach, salt, etc) are horrible to the environment and much, much worse than glyophosphate. I don't know how anyone could consider chlorine bleach to be a viable safe alternative. And even the vinegar (in the mentioned potency) is pretty dangerous to handle. There is a thread below called "Formulas That Work" that outlines the important concerns of many "regulars" on this forum - reading it may help you to get some approaches that will work in your area. I know many people that stay quite organic, but will still use glyosphosphate, which breaks down in the soil extremely quickly.

Roundup is deactivated once it hits the soil, so drenching the soil won't do any good. It kills through contact with the leaves. When it comes to Bermuda grass, repeated applications are necessary. It also works best when the plants are growing well. Solarization might work. Pick a time when you're going to have a week or so of hot sunny weather. First, thoroughly water the area that you want to kill. Then cover it with clear plastic and weigh the edges down to keep the plastic in place. This will kill everything under the plastic, including earthworms, soil microbes, etc, so you may want to topdress with some compost after doing this.

I know that some people have grown Palmetto St. Augustine at least as far north as the Tulsa area and have been happy with it. However, there will be years where it may freeze back significantly. While it can tolerate more cold than 'Raleigh' St. Augustine, one thing that is really hard on all St. Augustine in Oklahoma is when we have a really mild spell of winter weather for a prolonged period so the grass doesn't even go completely dormant, and then the temperatures suddenly plunge extremely low in just a day or so. It is that abrupt change from a warm and mild winter to a suddenly bitter cold one that often hurts St. Augustine grass. I am as far south as you can go in zone 7b southcentral OK without crossing over into Texas, with Texas to my east, south and west and we have problems here in our county with early freezes or big fluctuations in winter temps causing a lot of St. Augustine dieback. It is my favorite grass. I had 'Raleigh' St. Augustine in Fort Worth in the 1980s and early 1990s and loved it, loved it, loved it. Our next-door neighbor here had St. Augustine when we moved here and I said I was going to watch his and replace our bermuda grass with St. Augustine if his grass thrived for a couple of years. So, here we are 14 years later and his St. Augustine is almost entirely gone, and we still have our bermuda grass. I wouldn't make a huge investment in it initially. Is there a sort of out-of-the-way spot in the backyard where you could plant a small area of 'Palmetto' as a test and see how it does for a couple of years before you commit to planting a lot of it? By the way, the people who posted about 'Palmetto' on this forum a couple of years ago had found a local source in NE OK but that was probably 3 to 5 years ago and I don't know if it still is available up there. Down here, I always see some St. Augustine plugs or sod in local home improvement stores like Home Depot or Lowe's, but probably not until late April or May. Dawn

This is an easy one. The half the Internet that says to kill it off is apparently unaware of the southern part of the US. Both of the dominant grasses, bermuda and St Augustine, can recover by themselves. The half of the Internet that says to put down seed is apparently unaware of the fact that now is a terrible time for bermuda seed and that there is no St Augustine seed. Now is the best time to get rid of the weeds you have. If you want to keep the St Augustine, there is one herbicide ingredient to look for, atrazine. Here's one version of it...Note the purple color on the label. That seems to be the color for atrazine products. Read the label 3 times before you use it. Atrazine is a dangerous chemical, so you don't want to get it on you. Read the label for instructions how to apply. And keep your puppy off of the wet spray. Atrazine takes a few weeks to work, but in 3 weeks you should notice that there's nothing but St Augustine left. Always mow St Aug at your mower's highest setting. You can let it go several weeks without mowing for better results. It will spread at least 15 feet a year in all directions. If you already have patches scattered around, it will fill faster than if you only have it up against a building. St Aug will spread and cover up all the other grassy weeds; but the weeds you have are not grassy. The horse herb (3rd picture) is the bane of your life, but the atrazine will kill it out. If you keep after the horse herb once a year with the spray it should go completely away. Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall. Fertilize any time with organic fertilizer. The first chemical fertilizer should wait until Memorial Day. Second chemical fertilizer goes down on Labor Day. Last one can be around Thanksgiving.