When to apply initial fertilizer
Updated: Sep 7
Applying starter fertilizer is not necessarily a “slow and steady wins the race” situation. The goal of starter food is to give grass seedlings the extra boost they need to sprout and create strong, healthy root systems. To do this, you need to know when to give your new lawn or plants initial fertilizer.
The appropriate time of year to apply starter fertilizer depends on your lawn type and when you plant new plants in your garden. But no matter what you plant, you'll want to spread a starter fertilizer into the soil before sowing new seeds or laying down sod.
How to choose the right time to apply early fertilizer
As mentioned earlier, when planting seeds or laying sod, it is important to provide nutrients to the sprouting buds. What's the best way to do this? Apply starter fertilizer just before or after planting. However, before applying fertilizer, you should consider the type of grass you are planting and make sure you are planting at the appropriate time of year.
Cool season grass
Cool-season grasses, such as Kentucky bluegrass or tall fescue, should be planted in late summer or early fall when temperatures are cool but not freezing. September or October are ideal months for planting cool-season grass seed or laying sod. Apply a starter fertilizer to the soil immediately before planting new grass.
Warm season grass
In comparison, warm-season grasses such as bermudagrass and zoysia grass should be planted from late spring to early summer May to June. As always, for best results, apply starter fertilizer to the soil immediately before planting seeds or laying sod.
How to properly apply initial fertilizer
Getting the most out of your starter fertilizer requires more than timing. You want to use the right fertilizer for your soil and plants and follow all the steps in the correct order.
If done correctly, you will have a lush, green, healthy lawn! Sounds good, right? Here are the basic steps to follow when applying fertilizer to your lawn:
Test your soil
Perform a soil test to ensure your new grass seed is getting all the nutrients it needs. This lets you know exactly how much nitrogen, phosphorus, and potassium is missing from your soil. Once you have that number, you can get your hands on the right type of starter fertilizer and get to work.
Soil test results can take up to several weeks, so plan ahead!
For seed planting projects, aim to achieve a balance of nitrogen and phosphorus. Your lawn needs both equally.
However, if you are laying grass, use more phosphorus. Additional kicking will help the roots establish quickly.
Choose the right fertilizer
Read the label carefully to find out what your starter fertilizer has to offer. Aim for a higher nitrogen and phosphorus mix. They are responsible for excellent root growth and the beautiful green color of your lawn.
You want your fertilizer to be low in potassium. A new lawn does not need this. A fertilizer mixes such as 10-10-10 or 12-8-8 is ideal.
To get started, check out our most popular lawn starter fertilizers. Our guide to choosing fertilizer can help you figure out which product is perfect for your soil.
Take the time to properly prepare the soil. You want a product that is soft, loose, and easy to work with. This will allow young roots to penetrate more easily, get the essential nutrients they need, and thrive in the long term. Don't rush this process. It is worth spending extra time preparing the planting site.
Remove large debris and break up the soil using a rototiller, cultivator, or hand tools.
Check your lawn for pests and treat any infestations before planting new grass.
You can always add a little compost or manure to the soil mixture and add a couple of inches on top.
This creates a resilient surface, which is essential for planting seeds.
Lawn starter fertilizer application
Now it's time to prepare your fertilizer tools. For liquid fertilizers, you will need a pump sprayer or hose end sprayer, and for granular fertilizers, you will need a spreader or drop spreader.
Whatever type of fertilizer you use, spread it on the prepared soil and make sure it is evenly distributed. Don't forget to water. This will help the roots and seeds absorb nutrients faster.
Aim for 0.5 to 1 pound of nitrogen per 1,000 square feet.
Spread lawn fertilizer 4 inches deep into the soil. This will allow the grass roots to reach deeper into the soil.
Wait at least six weeks before applying additional fertilizer. Otherwise, you may burn the grass.
Lay or sow new grass
The wait is finally over. Now it's time to plant new grass! Lay sod or sow seeds to create a new lawn. Gradually, your lawn will begin to take shape and you can now sit back and enjoy the fruits of your labor. Germination can take up to 30 days, so continue to water and maintain your lawn in the meantime.
If you want to apply seed fertilizer right after planting the seeds, do so. But generally speaking?
We recommend that you apply in advance. Either way, you will need to water the fertilizer carefully.
In general, it is better to use liquid fertilizer rather than granular fertilizer.
Avoid using herbicides for at least four weeks after laying the lawn or until the third time you mow the lawn.
Understanding the role of seed fertilizer
Have you ever thought about how starter fertilizer works? Simply put, it's like providing a quick snack of nutritious ingredients that your new plant's root system can't yet access.
Think of them as three choices: nitrogen, phosphorus, and sometimes potassium (NPK) to help these little guys thrive!
This nutrient helps give plants their vibrant green color.
Phosphorus, or phosphate, is very important for optimal root growth, so it’s a good idea to add a little more. Make sure your starting fertilizer contains at least 20% phosphorus.
It is not very important for early growth, so starter fertilizers usually contain only small amounts of potassium. This helps make mature plants more resistant to disease, low temperatures and other environmental stressors.
Note: Now you know why it is important to be careful when applying starter fertilizer. If you have new plants or a lawn, it is best not to overdo it with fast-release nitrogen. As a rule of thumb, you don't want to add more than 1 pound of nitrogen per 1,000 square feet to your new lawn.
Other things to consider when applying starter fertilizer
Consider other factors before applying initial fertilizer.
Are there any bare spots on your existing lawn from the previous season? Add starter fertilizer and sow grass seed before sowing. That little bit of starter fertilizer will give your new seedlings the extra energy and resources they need to establish new roots.
But be careful. Starter fertilizers are not formulated for established lawns and may damage existing lawns. A soil test can help you choose a fertilizer with the right nutrients for both old and new lawns.
Compost instead of chemical fertilizer
If a soil test shows that your soil is lacking in organic matter and nutrients, choose compost or another organic fertilizer instead of synthetic chemicals. In addition to providing the nitrogen and phosphorus your new lawn needs, it also provides additional benefits:
Improve soil aeration
Promotes oxygenation of roots.
Retains soil moisture longer.
Continuous supply of nutrients to the roots
If initial fertilizer is not used
Early fertilizers are very convenient, but in certain situations it is best not to use them at all. These include:
In extreme temperatures or drought
Areas with high runoff
In soil already rich in nutrients or organic matter
Starter fertilizers can provide young plants with essential nutrients so they can quickly develop strong root systems. However, timing and dosage are two key factors when using starter fertilizer.
Too much and you risk burning the roots. Too little and your plants may not have the nutrients they need. Aim to apply seed fertilizer before or immediately after planting seeds and follow label directions for best results.
However, if you don't like the DIY approach or need a little extra help, you can always get professional help. A local lawn care professional can help you evaluate your soil and provide a fertilizer that suits your needs.