Many native landscape specifications call for watering of prairie seed if it is installed in July or August. As noted above these months were unseaonalbly cool this year and we had plenty of rain in our area. What if tempertures were hot and percipitation was minimal? Is watering the right thing to do? Here are some things to consider.
The cover crop, like most turf products, does not actively grow during July and August. Watering during the late summer will not make it grow faster. It will likely fill in during the early fall prior to winter.
Native seed typically will not germinate during this time period. Soils are typically too hot for native seeds to germinate with or without water. However, this may not hold true this summer due to the cool weather.
Due to the record coolness this summer, the seed may germinate if too much water is added this late in the season. If the native plants are induced to germinate now through watering, they may not develop enough roots to overwinter and could be lost next season.
Over-watering can drown seedlings, especially on heavy clay soils. Watering can encourage seedling loss by fungal attack.
If the seeded area is covered with straw blanket. This blanket will prevent seed from drying out, reduce exposure to wind and animals, and is important in preventing erosion on slopes.
It is reccomended to only water enough to keep the soil moist in native areas. This year we have had enough rain to achieve this goal. Supplemental watering may do more harm than good.
Keep these thoughts in mind prior to spending money on water trucks.
This is a great time of year to treat perrenial and biennial weeds. 
