I'm a huge fan of hydromulch.
I'm not sure why it hasn't caught on as much as it should. Perhaps due to the strength of the sod industry or perhaps the fact that hydroseeding/hydromulching is labor intensive. I'm not anti sod by any stretch of the imagination, but there are a few instances where it just doesn't work. And while there is some degree of instant gratification with sod, it may come with challenges that aren't needed.
The first is when we need to be using grasses or are working in places where sod isn't readily available. Both instances have made for some construction decisions that were up to others to fix later. Better to embrace the facts and look for better ways to seed.
The second comes when seasonal timing or climate (namely wind), make successful germination of seed a dramatic challenge.
Lastly, I don't love soil layers and unless things are really perfect, hydrosprigging/ hydroseeding/ hydromulching brings an advantage in not bringing in soil material that doesn't belong.
So there's the reasoning. The application is pretty easy by using some simple rules.
1. If we are working on greens we drop seed and dimple the seed in before applying hydromulch over the top. I learned the hard way never to put bentgrass seed in a hydroseed tank.
2. Never use the unit mounted "gun". It requires the machine to run a pretty high pressure and gets mulch in a lot of places that you don't want it. It's hose dragging time.
3. Addition of fertilizer to the mix tank is encouraged. You can pretty much do what you want here. The mulch will carry it.
4. Don't skimp on mulch quality. I happen to spec CanFor's Eco-Fiber or Eco-Aegis (for slopes steeper than 3:1). 1800-2000 pounds per acre is the starting point rate.
5. A good tackifier is important. Again, I happen to like and spec Finn Stik-Plus, but there are lots of good ones. Use no Guar Gum. Again, learned the hard way. Leave that stuff for the roadside.
What the mulch gives, and this is really important for that renovation job that has to be perfect, is a margin for error when it comes to moisture control. And by the way, moisture control is everything for germination and maturation of young grass plants. Being able to water and not have run off is good. Being able to use less water when your water quality sucks is good. Being able to water just enough and overcome the windy day or the hot day or an irrigation system malfunction is very good.
Finding a small unit is pretty easy. Or a small contractor. So small jobs can be accomplished and for us on the golf course, speed is not as important as perfection, so filling up a small unit a few times is not really a factor. If you bring in the SS Minnow fully loaded, expect it to sink to the axel right in front of the pro shop.
Take a look at Hydroseeding/Hydromulching for your next grassing operation. It may well make a ton of sense.