you can use straw or hay, whatever is convenient. what i actually used was mostly bales of pasture grass hay and bales of sugar can mulch, straw quiet often contain seed from the left over harvest, harvesters do not harvest 100% so you can get growths but these are not weeds and nothing to worry about, i have used straw and experienced that, but where it is possible to get grass growing from hay it is not any more probable, our instances of sprouting from hay are negligable. any sproutings we do get we pull up when they are large enough and tuck them under the mulch as extra nutrient, they have never become a perpetuating weed. we spend almost nill time weeding. the grass we had to cover was kykuya (spelling?) it is a very hard grass to control in the same league as nut grass, so we feel confident that if anyone uses the same processes we did they will get just as good results. once a grass is destroyed it does not matter how strong the runners or seeds are they will not survive the composting effect under the process we use. len Here is a link that might be useful: len's garden page

I donÂt have enough strength in me to hire a different company  I feel bad leaving these guys without a job. Yes, IÂm that weak... Well grow some brass ones, because you are being taken advantage of. Your contractor is use to getting told to take a hike. You will being both of yourselves a favor, fire him NOW. The problem is not your variety of Bermuda grass, keep the same practices you use now, and whatever variety of Bermuda you use will fail. Fire your contractor NOW, he is killing your grass with his advice and practice. Otherwise continue dump money in a bottomless pit. Ok enough of the soapbox stuff. What is giving you problems is watering schedule, fertilizer, and mowing Watering: You are over watering the grass, and is the source of your fungus and weed problems period. You cannot depend on anyone, the grass will tel you when it is time, You have to learn when by observation period. No one can be trusted. GOT IT? To determine if it needs watered is as simple as when you wake up, or go to bed each night. Go out and walk around and look at the grass. When you walk look back where you walked. Do your footsteps disappear quickly, or do your footprints remain? If it springs back means it is hydrated and OK. If your footprints remains it needs water. But the best method is a color change from deep green to a slightly blueish or graying color change. When Bermuda or really any grass is properly hydrated, the leafs of the grass open fully to expose the upper surface to sunlight and looks vivid dark green. However when it dries out it has a built in defense mechanism. The leaf will curl up to minimize its exposure to sunlight to conserve evaporation losses. This exposes the underside of the leaf which is a different color. For Bermuda grass that is a blueish or grayish color telling you to water. Sorry to be ruff on you but you need a wake up call, and learn to take care of the watering yourself. As for fertilizing and mowing, let's stop here until you respond with questions.

Lasagna composting with newspaper and grass cuttings. Google it. It really works, to kill grass/weeds, as well as great soil-improver. I don't know why it works, but I know it does. Some folks believe tilling just destroys whatever structure you already have in your soil, so no-till is trendy. I layer newspaper (maybe 3-5 sheets, overlapping edges), then an inch or two of grass clippings, then newspaper again and so on. A few layers works great (more if you need more to smother grass), and a little mulch on top makes it all look pretty while the grass underneath is dying. Then in a couple of months, plant right in it.

Also for weeds in areas like walks and gravel paths...1 gallon of white vinegar 2 cups Epsom salts 1/4 cup of dawn blue liquid soap. mix well in a canister sprayer spray early morning weeds deed by night. also on large areas like driveways buy a torch from home depot or the place I linked below along with a propane tank like you use on your outdoor grille and just burn them away. Roundup is just a terrible terrible product!!! Highly toxic kills wildlife causes illness such as cancer to humans, pets and woodland creatures. Get into into the water table. https://jet.com/product/65a277740865404bb94361416de71a4a?jcmp=pla--ggl--home_garden_other--lighting_tiki_torches_oil_lamps_other--.--.--.--.--.--2&code=PLA15&k_clickid=ac203f78-ba5d-43af-9925-0231c8a37b3b&kpid=65a277740865404bb94361416de71a4a&gclid=CPf_3eWqqccCFckYHwodVfwLIQ