We all know that hydroseeding is a better alternative than broadcast or even slit seeding, but regardless of what kind of seeding you are doing, timing is an important factor.
While its not possible to control the weather, you can properly time your seeding to help mitigate the effect of outside factors including:
Crabgrass prevention application
Seeding in the middle of the Summer heat is a recipe for mixed or poor results. The heat and sun can fry and ruin your seeding job in just one day without proper water. Weeds also thrive in this environment while establishing grass does not. Before the seed germinates, the heat beating down on the dirt can actually burn up the seed before it even gets a chance to germinate.
Once seed has germinated, the seedlings are very sensitive to excess heat and drying out. Again, just one day with lack of water in intense heat can mean the end of your seedlings.
Once the seed is moderately established you are at less risk of loss, but a few hot and dry days could stress the new turf and kill it. The reason is because while the grass may appear healthy and established, it does not yet have a deep root system. Because it does not have a deep root system, it will dry out just as quickly as the surface soil dries out.
On the flip side, cold is also a factor in many northern climates. Seeding in the early Spring or especially in the Fall can be a risk/reward proposition.
Early Spring seeding can be very rewarding because you can beat the heat, weeds and get lots of moisture from the sky instead of running irrigation. The risk is, that if you seed too early and there is a warmer than average stretch of weather the seed will germinate. If the seed germinates and then there is a hard freeze, the seedlings may freeze out and die.
There is an even greater risk of this in the fall. Fall seeding is typically thought of as the BEST option for establishing new grass, but you have to hit the timing correctly. In our southern Minnesota climate, the end of September is about as late as we will risk seeding until we get into “dormant seeding” season (more on this later). The reason for this is the same as why it's risky to seed in the late winter/early spring. If the grass germinates but does not well establish before a hard freeze, it could freeze out and die.
Dormant seeding is a totally different concept and it carries the same basic risk as late winter/early spring seeding. Dormant seeding is when the hydroseed is applied in the late fall/early Winter after the growing season is complete. The expectation is that the seed will take advantage of all of the moisture from snow melt and spring rain and be down much earlier than you could feasibly prep and apply hydroseed in the spring season. There will also be no competition from weeds during this establishment period.
The problem with dormant seeding is that sometimes if it is a harsh winter with little snow cover the seed can freeze out. There is also more risk of the seed being eaten by birds and other critters in the late Fall/early Winter before snow cover. In years where these outside factors don’t apply, dormant seeding is a great option. But as a contractor, it is risky, because if no seed germinates in the spring, the customer is going to be calling.
No matter the season you plant in, weeds are always going to be a factor when it comes to the success of your hydroseed. Our suggestion is to ALWAYS use Tenacity (https://www.reinders.com/products/chem-tenacity/) at the time of seeding to help eliminate any existing weeds in the soil as well as prevent new weeds from popping up during the early stages of your seed establishment. As weeds do start to appear, we suggest spot treating them until the turf is well enough established for blanket herbicide applications (consult your local experts, every climate and grass type is different).
The last factor that we hear about over and over is people who seed their lawns or seed a lawn for a customer, that customer signs up for a lawncare program, and the lawncare provider applies crabgrass preventer such as Dimension in the Spring. The problem with putting down a pre-emergent like Dimension is that is prevents the germination of all grass seed, including the seed you are trying to establish your lawn with.
At VSI we love to see people succeed with hydroseed, whether you are a contractor, homeowner, golf course or facility manager. If there are any questions we can help answer to ensure the best possible results, don’t hesitate to reach out!