I don't know what your temps are where you're at, but normally you would be doing all of this at the wrong time of year in most other parts of the country. Fall (Sept/Oct) is the prime time for seeding. Getting back to Tupersan, I've used if before and it does a fair job at holding back the weed seeds while allowing grass seed to germinate. But keep in mind, this stuff is pretty pricey, not to mention it will only last around 5-6 weeks, if that long. I can't remember how long it lasted when I used it, but it wasn't as long as I thought it should be. Anyway, it should be long enough to get the grass germinated if the heat doesn't get you. Don't know how hot it gets in San Jose this time of year. If it gets in the 90's...don't expect a beautiful lawn real soon, because the young seedlings will die, but some should survive for a better fall planting.

Dave, I think they they may be overused and are useful in a limited set of circumstances. A row of conifer screening happens to be one of those uses. Yes, the fabric (and I was only recommending a geotexile type, not a roll of impervious black plastic) will degrade. By the time it degrades completely, the conifers will have grown large enough that their shade will start to cut down on weed germination. In my observation, they undoubtedly increase soil moisture retention and reduce the need for watering. And in their first couple years, they do keep weeds down, which is the most crucial period for reducing weed competition as the plants are getting established. Later on, the few weeds that start growing in the mulch are easy to rake or pull out. I've had some in my landscape now for 5 years, all the plants around it have grown just fine, I've never had to water them in the past 3 droughty summers, and I expect in 5 years it will probably mostly degrade but by then it will be filled in with mature plants and there will be less light for weeds to grow. One size does not fit all and the article you posted has some good points, but I stand by my recommendation. BTW Ken's recommendation to not make a screen of a single plant type is good too.

Just moved into this house a little over a year ago so late spring I put down some weed n feed then late summer I put down some fertilizer can't remember the numbers but just nitrogen X-0-0. Controlled most of the Sandburs but by the end of the year I had some coming in in a few spots. Water at least once a week deep (sandy soil) with well water. Last year I mowed at around 2 1/2 - 3" going to see if I can do 1 1/2 or 2" this year( not the smoothest of yards but working on it). I only bag the first time after that I mulch. I attached a photo and the area in green is my main yard I want it to look as best as possible, area in red is what I keep mowed but it is relying on rain for its water. Blue is my property and cows take care of what I don't mow. Ramping up my operations this year I built a tow behind sprayer so I can't try to keep everything in red looking good. Blue area is around 9 1/2 acres

Crabgrass is a summer annual plant that only returns by seed the following spring. It has a quick-germinating seed, so if you try to establish grass in the spring, the first seedlings you see will almost always be crabgrass. Then if you think the new crabgrass sprouts are your target grass seed coming up, there is a tendency to stop the daily watering. Once you do that the target grass seed just sits there while the crabgrass fills in. It is adapted to heat, low mowing, and dry spells. It's also yellow and shaggy compared to more popular turf grasses. The best way to avoid getting crabgrass is to create a dense turf to begin with. The best way to do that is to make it dense in the fall after the crabgrass has stopped germinating seed. You can kill it out to create open space, seed into the open space, and the new grass will provide that density that keeps the spring weeds out. If you start early in the fall (in northern Utah that means August), then you will have time for the new seed to come in and still reseed if it was not dense enough. Continuing with the best way to keep crabgrass out, if you can withhold water in the spring and keep to a temperature driven watering schedule, that will deprive the summer annual weed seeds from the continual moisture they need to germinate. And the last thing you need is to provide as much shade on the ground as possible. Do that by mowing the grass at the mower's highest setting. Beyond those cultural practices you can use preemergent herbicide as has been discussed. Ideally you will develop a turf that is dense enough that you won't get crabgrass. I have not had crabgrass in forever with a dense St Augustine lawn. 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.