when to fertilize new grass

Keeping your grass green and healthy doesn’t have to be all that difficult. Unfortunately, it does require that you spend at least a bit of time on lawn maintenance, which means mowing, seeding, fertilizing and aerating as needed.

All of these factors become especially important when planting new grass, but the problem is that the majority of people are fairly clueless when it comes to deciding how often and when their new grass should be fertilized. With this in mind, we have produced this handy guide to tell you everything you need to know about fertilizing new grass.

A Brief Intro to Fertilizing New Grass

Whether you have just laid down sod or sown new grass seed, fertilizing the lawn can provide major benefits in terms of providing the fledgling grass with the nutrients it needs to grow strong and healthy.

The issue is that there is a lot of conflicting evidence and advice as to when is the best time to fertilize your new grass in order to gain the biggest benefit. This problem is born out of the fact that there are numerous types of lawn grass, and the type of grass you plant and your local climate will be the biggest determining factors in when you should start fertilizing.

Some experts claim that the soil needs to be fertilized prior to laying down new grass seed or sod, while others claim that waiting until after provides far better results. This can be quite confusing until you realize that both are actually correct. It’s important that your soil has the proper nutrients necessary prior to laying down sod or sowing new grass seed, but equally as important is that the soil has enough nutrients to sustain the growth once the new grass takes hold.

What Nutrients Are Most Important for a New Lawn?

Generally speaking, you are best to fertilize your lawn as one of the final steps prior to laying down sod or planting new grass seed. Grass requires a range of nutrients to achieve its full growth potential, and most important are nitrogen, phosphorous and potassium (N, P and K).

The problem is that most grass fertilizers contain these nutrients in percentages designed to stimulate existing grass growth, and these concentrations are often not the same as required by new grass. Therefore, it’s important that you understand what these fertilizer numbers mean and use them to help you select the best product.

Most grass fertilizers have either too high of a concentration of N, P and K or take the form of so-called ‘weed and seed’ fertilizers, and neither of these are sufficient for newly sprouted grass seedlings nor freshly laid sod. Freshly laid grass seed or sod requires easy access to these essential nutrients.

The problem is that most fertilizers are actually too strong and will end up causing fertilizer burn or completely killing your newly planted grass. Similarly, the various ‘weed and seed’ fertilizers are also not sufficient for new grass, as these products generally contain various additional chemicals that can actually stop grass seeds from sprouting or can harm or even kill the new seedlings.

Seed vs. Sod: Choosing the Right Type of Fertilizer

It’s highly recommended that you only ever treat a new lawn with either a ‘starter’ fertilizer or a ‘slow release’ fertilizer. If you’re starting a new lawn from seed, it’s far better to use a ‘starter’ fertilizer. These fertilizers usually have a much higher phosphorous content and a slightly higher concentration of potassium.

Newly germinated grass seedlings require higher levels of these two essential nutrients, which is why a starter fertilizer can be such a big help. Of course, these essential nutrients also need to be easily accessible, which is why it’s recommended that you work the fertilizer into the soil just before seeding.

Established lawns generally require a different type of fertilizer. This means that if you’re laying down sod, it’s better to use a slow-release fertilizer, such as an 18-1-8 NPK formulation. As with starting from seed, you’ll want to mix this fertilizer into the soil prior to laying down the sod.

If possible, you might also want to consider having a soil test performed prior to seeding or laying down sod. A soil test is the easiest way to determine the pH of your soil and will also help to provide information about any nutrient deficiencies that you can correct through fertilizing.

Fertilize, Grow, Fertilize: What Is the Best Fertilization Schedule for a New Lawn?

sodGenerally speaking, you should plan on fertilizing the soil once just prior to sowing grass seed or laying down sod. However, after this initial fertilization, it’s recommended that you avoid fertilizing the new lawn for at least six weeks to allow the grass to get established. After six to eight weeks, you can then start fertilizing as you would with any established lawn.

If starting from seed, you are usually best to first use a starter fertilizer, and then a month or two after the seeds have germinated, switch to using a traditional slow-release fertilizer. If you’re starting from sod, you can generally use the same fertilizer throughout the process. However, it’s still recommended that you fertilize once before laying the sod and then again after another month or two. Alternatively, you could simply use a slow-release fertilizer prior to laying down the sod and then apply the fertilizer again as directed.

Either way, the newly planted grass will generally use up the nutrients in the soil quite quickly. This is why it’s a good idea to fertilize again after six weeks or so to ensure that the grass has all the nutrients it needs to grow strong and healthy. Neglecting to fertilize your lawn once it begins to become established could potentially see your new grass starved of nutrients and thus severely harm its growth potential.

Whether you’re using seed or sod, starting a new lawn isn’t all that difficult. However, it does require that you pay special attention to fertilization in order to ensure that the grass has all of the essential nutrients it needs. In this sense, it’s important that you focus on the soil prior to planting the seed or sod and then make sure to start fertilizing the lawn again once it’s established. By following these simple steps, you should be able to easily grow a new lawn that makes you the envy of your neighbors.