All that work would be in vain. If you have any existing grass at all, please nurse it through the summer and reseed in the fall. Here's why. Now is the ideal time to germinate crabgrass seed. For best germination, crabgrass seed needs to be watered twice a day for two weeks. Sound familiar? This is the second reason why spring time is not a good time to seed your lawn. The first reason is that your new grass does not have time to develop sturdy roots before the summer heat hits. Then you will have both a great stand of crabgrass but also a declining turf that lets the crabgrass spread. Forget about pH for now. Worry about your grass. If you follow the following suggestions, by Memorial Day you will have a near weed free lawn that looks very nice. 1. Water deeply but infrequently. Deeply means an inch at a time, all at once. Infrequently means no more than once a week during the hottest part of July. In the summer heat I water each zone for 1-3 hours and my zones overlap by 50%. The point of this approach is to allow the soil surface to dry out completely between waterings while the underlying soil still has some moisture. Weed seeds are on the surface and they need continual moisture. When you let the surface dry out, it breaks the seed's moisture requirements and it will not germinate. 2. Mulch mow with your mower set to the highest setting. Leave it high until you come in to reseed in the fall. Tall grass survives the summer heat much better than short grass. Tall grass grows deeper roots. Tall grass keeps the soil cool and suppresses evaporation. Tall grass also will prevent necessary sunlight from hitting seedlings and letting them photosynthesize enough to take root. You can be surrounded by weedy yards and not do anything to still have a weed free lawn. Weed the weeds you can with a Weed Hound tool. After that your new watering and mowing routine will keep almost all weeds out of your yard for zero cost and zero effort. If you are willing to spray chemicals, spot spray individual broadleaf weeds with Weed-B-Gone. If you would rather spray an organic measure, try regular vinegar as a foliar spray used in full sun on a hot day. If you have already fertilized, fertilize again on Memorial Day. If you have not already fertilized, apply a half load now and the other half on Memorial Day. I pick Memorial Day because it is easy to remember the federal holidays. I use organic fertilizer on all the federal holidays. You can do that with synthetics, too, if you skip 4th of July. Summer heat problems again.

+1. Nitrogen is what gets used at this time. P and K consumption aren't much different (lower, actually) than they are at any other point in the season. High N levels (which turn to carbohydrates after use and photosynthesis, indirectly) will increase winter survivability and may keep your lawn greener over the winter. Potassium is pretty much harmless in modest amounts in winterizer, so most winterizers do have a little of it. If you were short, potassium will help with cold tolerance. But it's best if you kept the potassium at the correct level throughout the season as it's an all-around good weather tolerance enhancer and helps with disease resistance. Potassium is also not a water pollutant. It doesn't increase eutrophication (the tendency for algae to bloom in waters and choke out other life). There's always and already tons of the stuff kicking around. I never heard about the K increasing the chances of snow mold, but it does make sense. Increased K increases cold resistance, keeping the lawn greener further into winter when it can be snow-covered and then grow snow mold. However, if your P levels were optimal, that's happening anyway (and I'd never recommend a non-optimal level). Phosphorus does cause eutrophication, and application late in the season encourages erosion of it and runoff as it doesn't penetrate soils quickly. The latest I recommend P additions is about six weeks before ground freeze, and I usually try to cut more time than that. Spring, summer, and early fall are the correct times to enhance phosphorus levels.

Turgeon has an interesting perspective on phosphorus (P). When you read the quote below from Turfgrass Management, keep in mind there's a difference between available P in the soil and unavailable P in the soil (in other words, P in the soil that's available to the plant and P in the soil that's unavailable to the plant). Together they equal Total P. I guess the "available P" in the soil is the phosphorus that the beneficial fungi got in them and trade with the plants in exchange for exudates the plant's roots give to the fungi. There's a symbiosis there between plants and fungi. Each wants something the other furnishes. Turgeon: "The phosphorus concentration of dried turfgrass clippings is usually less than 0.5% compared with 3% to 5% for nitrogen." "Phosphorus deficiencies are most evident during turfgrass establishment. Generally reduced growth, dark to reddish leaf coloration, and narrow leaf blades indicate a deficiency in available phosphate in the soil. A soil concentration equivalent to 30 pounds per acre of available phosphate is considered a minimum level for turfgrass growth." [That's roughly 0.75 pounds per 1,000 square feet--we'll round and say 1 pound per 1,000 square feet. That's the minimum needed and I'm guessing the vast majority of soils have that available. Back to Turgeon again below.] "As phosphates are relatively immobile in soil, they do not leach readily from the turfgrass root zone. Many turf soils that have received liberal quantities of phosphorus-contaning fertilizers are, thus, high in total phosphorus. However, the plant-available phosphorus concentration in the soil solution is usually a small percentage of the total concentration due to the rapid rate at which phosphorus becomes tied up in insoluble forms. The phosphate ion (H2PO4-) combines readily with iron and aluminum cations to form insoluble compounds, especially in acid soils. In many instances the amount of available phosphate in the soil is surprisingly low compared with the amount removed by actively growing turfgrasses. This is apparently due to a dynamic equilibrium between soluble and insoluble forms of phosporus; as the available pool is reduced by plant uptake, some ot the insoluble phosphorus becomes soluble at a sufficient rate to sustain turfgrass growth requirements. On many turfgrass sites where clippings are not removed there may be no need for phosphorus fertilizer as long as the residual supply from previous fertilizations is adequate."

2 year update! The Turf Blue bluegrass has adapted very well to the NC environment. Disease has not been an issue - which is refreshing, and the cultivars in the mix are very aggressive - they filled in 6" holes left over from dead Bermuda in 6 weeks. The relationship with this mix has been a bumpy one. There have been periods when the grass looked lime green and I've seriously considered nuking it, but the fact it's so resilient stopped me. Meanwhile, I've learned to work with it, and it with me. I've learned that cutting below 2.5" produces some sort of reaction in the grass and it starts to put out massive amounts of new lime-green growth. As soon as I stopped trying to go lower and stabilized the HOC at 2.5", the color issue went away. Also, color has improved with age. And finally, PGR and FAS bump up the color significantly as well, bringing it into the acceptable range for my taste. Drought tolerance is similar to fescue, maybe slightly less. However, recovery from dormancy is outstanding, so even if it browns a little, it comes back with a vengeance. And where it doesn't, it spreads to fill in. It's peace of mind, and it's priceless. Because I know I can afford to push it and let go a little brown, I probably used less water on this summer that I used to use on fescue. Disease has not been an issue, brown patch doesn't touch it. So, I'm going into my 3rd years with the HGT mix. I am very pleased with its performance, and I expect even better now that it's mature. Color can be successfully managed, and it lives up to the H in HGT. Highly recommended as an alternative to fescue for the Transition Zone. http://lawniac.com/wp-content/uploads/2018/11/lawn_oct_2018.jpg