How Long Can Hydroseed Go Without Water?

Hydroseed is a nutrient-rich growing medium that is applied as a slurry to plant grass seed on bare soil. You can hire a professional to apply it, or do it yourself, but once it’s applied, it must be kept consistently moist for the following week or two that it will take for your grass seed to sprout in the mixture.

Daily watering is essential for proper germination and root establishment, so the hydroseed material, which acts like a sponge to absorb and hold on to moisture, can’t be allowed to dry out. It will need to be watered evenly three times a day like you would a normal in-soil seeding, either by sprinklers or by hand. If the growing medium dries out before the plant has sprouted, the interruption in consistent water supply can result in many, or all, seeds not germinating completely. 

What Is Hydroseed?


Hydroseed, or hydromulch, is a water-based mixture of grass seed, fertilizer, mulch, and a solidifying agent like paper pulp or a biodegradable synthetic binder. It’s applied to the ground that has bare patches or has been tilled to coat the topsoil and deliver a consistent supply of moisture and nutrients to support and speed up the germination process. 

Since the hydroseed material acts like a sponge, the material holds on to moisture longer than plain topsoil and can deliver more water to seedlings. This doesn’t mean, however, that it is a substitute for watering the seeds while they germinate. Hydroseeding needs to be watered as much as you would water a normal seed application for successful root establishment.

Water And Grass Germination

Water is essential for germination, and seeds need to remain moist at all times until they germinate, unlike mature plants, which can store water over periods of dryness. Seeds get their nutrient and oxygen supply from water, and the moisture provides the hydration plant cells need to produce enzymes, create sugars, and sprout stems and leaves.

Watering Lawn

In a hydroseed lawn, the germination process is sped up, with seeds usually sprouting in less than 2 weeks. The dense nutrient supply and consistent moisture delivery from the hydromulch give germinating seeds the opportunity to establish healthy roots and blades at the beginning of their lifetime. A dense lawn that gets lots of water while it’s growing will be healthier and able to deal with stressful conditions during periods of drought or wear. 

Should Soil Be Prepared Before Hydroseeding?

Before applying hydroseed, the ground should be aerated and moistened for the seeds and solution to make contact with the soil. Good coverage is important for the new roots to be able to reach the soil and stretch down into it. This is especially important for hard soil types. When you aerate beforehand, the soil is opened up so that air and moisture are incorporated into the topsoil, providing the best growing environment for the development of healthy roots.

How Often Does Hydroseed Need To Be Watered?

The hydroseed mulch needs to be kept moist until the seeds sprout so that they have a constant supply of water for proper germination. When you water seeds, whether they’re in a hydromulch or just soil, it needs to be done multiple times a day throughout the germination process. The hydromulch doesn’t replace the need to water and the same schedule needs to be kept no matter the growing medium.

The seeds should receive water for 15 to 20 minutes, three times a day until they sprout, at which time you can cut back to watering once a day since they will have some roots and seeds to store water from day to day. The best times to water are early morning, noon, and late afternoon. 

If you have an in-ground irrigation system, you can set a timer to make sure the schedule is kept closely, ensuring the seeds sprout and establish. If there is rain in the forecast, you don’t need to water as much, but it’s important to monitor the soil and the weather to make sure you’re not overwatering, or underwatering. Even if it rains one morning, you may need to make sure the seeds get some water in the afternoon as well. However, you don’t want to drown them if the soil is still saturated after a downpour.

Why Is My Hydroseed Not Growing?

What Is Hydroseed

There are a few reasons why your hydroseed might not have grown successfully:

  • It didn’t get enough water – The most common reason a hydroseed didn’t do well is that the seeds didn’t get enough water to germinate. If the seeds stop receiving water during germination, the process gets interrupted and they can dry out quickly. 
  • It got uneven water – If some areas grow in, but others didn’t, it’s likely from uneven watering patterns. Whether you have a sprinkler or are hand watering, it’s important that the whole surface gets enough water for the seeds to grow.
  • It wasn’t applied thick enough – A too thin layer of hydroseed might not have enough mulch or seeds to grow the dense coverage you hoped for. The seeds can grow in a bit of extra mulch, but too little mulch can lead to uneven hydration or too few seeds.
  • There was too little seed in the mixture – If you’re applying a cover of hydroseed yourself, you’ll be mixing the seeds into the hydromulch mixture yourself. If too few seeds are added, it might not give the full coverage you’re looking for and result in thin and uneven growth.
  • The soil was compacted or unprepared – If the soil is too compact, the seeds won’t be able to stretch into the topsoil to establish roots. Blade growth follows root establishment, so for a full lawn to grow in, the seeds need to be able to get their roots into the ground.