What Fertilizer Numbers to Use in Summer? – A Complete Guide

Summer is a very stressful and difficult season for a lawn. The heat of the sun and sometimes even no moisture in the soil can damage the lawn and even the lawn can die. So the best thing to do for the lawn for this season is to prepare the lawn for it. And to prepare you to need to make the lawn healthy and strong by fertilizing. But everybody has a question: what fertilizer number to choose for summer? 

The best fertilizer number for the summer season is 34-0-4. This is the perfect mix of all the nutrients for the lawn in summer when it is facing the heat of the sun and sometimes drought and can go into stress. The high percentage of nitrogen will help the grass and give enough food and a little bit of potassium to boost the process.

Now you know what fertilizer number to use in summer, but it’s not that simple. So let’s understand why this number is used and what is the best way to fertilize your lawn.

What are these numbers on fertilizer?

The numbers you see on the fertilizer bag is to help you determine what type of fertilizer you need for the lawn. These numbers indicate the percentage of certain nutrients available in the pack which is essential for the growth of the grass. These numbers indicate the percentage or ratio of NPK in the bag. So what does NPK mean?

What does NPK mean?

The NPK expands for Nitrogen, Phosphorus, and Potassium, where N stands for Nitrogen, P for Phosphorus, and K for Potassium as these abbreviations are the chemical notations of these elements.

  • Nitrogen – Nitrogen is a really important nutrient for the lawn as it provides the grass with the food to grow. Nitrogen is the main nutrient behind the green color of the leaves as it helps in making chlorophyll. This is the main reason you will find all the fertilizer with a high percentage of nitrogen to give the lawn a boost and healthy growth throughout the year. 
  • Phosphorus – Phosphorus is another nutrient that is really important for the lawn as it helps the plants to establish themselves in the soil by promoting root growth. This makes the grass hardy and faces the long and hot days of summer and sometimes drought because of the deep root system. 
  • Potassium – Potassium is a nutrient that helps the plant fight diseases and keeps the lawn healthy and thick. Potassium also helps the grass in boosting the process of food making and helps in absorbing water which makes it easy for the grass to grow. 

Where to find the NPK number on the fertilizer?

Finding the NPK numbers on the fertilizer pack is fairly easy as it is written on the front of the pack or sometimes associated with the name just like “Pennington Ultragreen Weed And Feed 30-0-4”. So finding the NPK number on the pack will not be a problem for you. If by any chance it is not mentioned on the front of the pack or just associated with the name, or it will surely be written on the label on the back with the recommendation guide on how to use it on the lawn.

What Fertilizer number to use in summer?

The best fertilizer number for summer is where nitrogen is in high quantity to give food for the grass to grow and stay green throughout the season with a little bit of potassium to boost the processes like photosynthesis, etc. 

So the best fertilizer number will be 34-0-4 to fertilize your lawn in the summer. I use “Pennington Ultragreen Southern Weed And Feed 34-0-4” for summer fertilization as it comes with all the things your lawn needs in the summer. 

This is an idol fertilizer for summer, but sometimes the condition of the lawn is not as we expected so different lawn needs different fertilizer numbers. Let’s have a look at it in detail:

  • New lawn – if you are going to start a new lawn in summer then it is better to use a fertilizer that can help the grass grow as well as to establish its roots properly so that it can withstand the heat or drought of the summer season. The best fertilizer number for this would be where nitrogen and phosphorus are in good amounts with a little bit of potassium. The “Pennington Ultragreen Starter Fertilizer 22-23-4” would be perfect for use and can make your lawn healthy and beautiful.
  • Old lawn – if you have an established lawn, then it will already have a good roots system that can easily withstand the heat and drought of the summer so a good amount of nitrogen to boost the grass growth with a little bit of potassium to make the process fast would be a good option. You can use “Pennington Ultragreen Southern Weed And Feed 34-0-4” as this is a perfect option. 
  • Poor lawn – if your lawn is struggling and is in very poor condition then the best is to first give it a little mix of all the nutrients to revive the lawn as the grass won’t have proper roots to help. Use “Pennington Ultragreen Starter Fertilizer 22-23-4” in the lawn as it will help the grass to establish roots as well as regain from the bad condition with the help of nitrogen and potassium. It will take a lot of time for the lawn to revive if the heat is high so try to fertilize as early as possible in the summer.

We also have a detailed guide on what fertilizer number to choose in spring. Do check it out.

When to fertilize the lawn in summer?

The best time to fertilize the lawn is in the late spring or early summer when the heat is low and the soil can stay moist for longer as fertilizer can sometimes be harsh and burn the grass if the soil is too dry. Fertilize the lawn in early to mid-May for the fertilizer to work before the stress of the summer kicks in and the grass is in better condition.

How to fertilize the lawn in summer?

Fertilizing the lawn in the summer is very simple and easy. You just need to take care of two things, the timing and the moisture in the soil. Let’s take a look at how to step-by-step fertilize your lawn in summer. 

  1. Make the soil moist – the first thing to do before you start fertilizing your lawn is water it one day before to make the soil moist. This will make the soil absorb the fertilizer as well as reduce the possibility of fertilizer burning the grass. 
  2. Check the label – read the label carefully of the fertilizer you are using and find out how much fertilizer to use in your lawn. This is crucial as you don’t want to over-fertilize your lawn and burn it down in the summer heat. 
  3. Apply the fertilizer – after measuring the fertilizer to use in your lawn, the best way to apply it is first to divide it in half and first apply the fertilizer in one direction and then in the perpendicular direction. For example, first, apply the fertilizer horizontally and then vertically so that you won’t leave any area of the lawn and also don’t over-fertilize any area. 
  4. Water the lawn – after applying the fertilizer, just water the lawn so that the fertilizer can go in the soil and to the roots of the grass and start releasing the nutrients immediately. If you don’t water the lawn the fertilizer can stack up in one place and won’t help the lawn in the way it should.

Hope you now know what fertilizer number to use in your lawn. Get Set Gardening!