Why Is My Grass Not Growing?

Find out what factors result in poor grass seed growth

Over the years, we have heard of homeowners struggling to establish newly planted grass seed. Have you ever noticed grass seed growing in the carpet of a car and cracks in the sidewalk? But why isn’t it growing where it is supposed to grow ― on your lawn? The problem is often believed to be the grass seed, but there are numerous factors in grass seed growth.

What is germination?

Let’s start at the beginning: What is germination? To germinate means to begin to grow. For example, ryegrass may take only seven days to germinate, but 21 days to grow to three inches. A mixture containing only 10% Ryegrass will not germinate quickly if the rest of the mix includes Kentucky bluegrass and fescues. If you would like quick germinating grass seed, check the product label for what types of grass are included in the mixture.

The species of grass seed you sow will help to determine when to expect germination. Ryegrass is the quickest species of grass to germinate. In the right conditions, it can germinate in only five to seven days!

Tall, chewings and creeping fescues are the next species to germinate, usually taking 14 to 21 days. Kentucky bluegrass is the slowest species, which can take 21 to 28 days to germinate. 

Temperatures

Many homeowners apply grass seed during spring months after raking the yard and finding bare spots. However, spring weather can vary each year significantly in the same area. The main reason grass seed doesn’t germinate quickly during the spring months is cold and wet weather. Would you rather swim in the ocean in April or August? You probably picked August, because the water is much warmer. The same goes for growing grass seed; it will germinate better in August than April because of warm soil conditions. Grass seed will not grow if soil temperatures are too high, either. It is best to seed cool-season grasses from mid-August through mid-October or mid-March through mid-May. 

Water

Water is necessary for seeds to germinate, but too much water can hinder germination. While watering newly planted grass seed is good for growth, overwatering will drown the new seeds, making them float to the surface instead of taking root in the soil. Too much water is why excessive spring rains can delay germination.

Sunlight

To grow, all grass seed needs some level of sunlight to produce chlorophyll and stimulate photosynthesis. When spring comes along and the tree canopy increases, less sunlight gets to the grass plants. If your shaded area receives only one to two hours of sunlight a day, you may have trouble growing grass. If this same area receives three to four hours of sunlight, whether filtered or not, your chances of success increase significantly. Frequently shaded areas have a low soil pH, meaning it is conducive to growing trees but not grass seed.

pH

Do you know the pH of your soil? Grass cannot grow in soil with a pH that is too low (acidic) or too high (alkaline). Test the soil in areas where you are having trouble growing grass seed before buying grass seed and fertilizer. Homeowner test kits are available at the Gasper Garden Center or send a sample to your county cooperative extension office for analysis. Gasper offers a Soil pH Test Kit that is easy to use, and you will have your results in five minutes! Once you measure the soil’s pH, you can add soil foods to create an environment in which the grass seed can grow!  

Mag-I-Cal Plus for Lawns in Acidic & Hard Soil

Jonathan Green’s Mag-I-Cal® Plus for Lawns in Acidic & Hard Soil contains calcium carbonate in an entirely soluble form that is immediately available to adjust soil pH upwards. Poor soil is often the problem in growing a great lawn, and calcium is vital to many grass plant functions. When soil is compacted or too acidic, air, water, and nutrients are unable to reach the roots, making it very difficult for grass to flourish. Lawns thrive in soil with slightly acidic to neutral pH levels ranging from 6.2 to 7.0. When pH levels drop between 4.0 to 6.0, weeds grow, and the grass becomes light green and spindly. Additionally, Mag-I-Cal Plus helps to break up clay and compacted soils. Aerated soil improves root penetration and promotes growth by increasing biological activity and releasing nutrients trapped in the ground.

Mag-I-Cal Plus for Lawns in Alkaline & Hard Soil

Jonathan Green’s Mag-I-Cal® Plus for Lawns in Alkaline & Hard Soil contains sulfur and calcium sulfate dihydrate, which lowers soil pH, is essential to cell development, and is vital to many grass plant functions. Poor soil that is hard and compacted is often the problem when it comes to growing a great lawn. When soil is too alkaline and compacted, air, water and nutrients cannot get down to the roots, and the grass will not grow properly. Lawns thrive in slightly acidic to neutral soil with pH levels between 6.2 and 7.0. In soils with pH readings of 7.0 to 9.5, weeds thrive, and the grass becomes light green and spindly. Additionally, Mag-I-Cal® Plus helps to break up clay and compacted soils. Aerated soil improves root penetration and promotes growth by increasing biological activity and releasing nutrients trapped in the ground.

Soil pH Test Kit

Jonathan Green’s easy to use Soil pH Test Kit determines pH levels in just five minutes. The kit includes one test tube, one capsule of powder, and one pH range card to indicate the results. It is essential to use distilled water or rainwater when performing this test to get accurate pH readings. Tap water has been pH adjusted by municipal water authorities, and this will affect the reading.

Fertilizers

If it has been a while since fertilizing your lawn, it might need a boost before the new seed can grow. The Jonathan Green Seeding and Sodding Fertilizer will supply the nutrients necessary to get new seedlings off to a good start. On the other hand, if you add too much fertilizer to your lawn, you risk damaging and burning your grass. 

Green-Up Fertilizer for Seeding & Sodding

Jonathan Green’s Green-Up Fertilizer for Seeding & Sodding is specifically formulated to grow quicker and thicker grassroots, which are essential for surviving the stresses of summer and winter. Jonathan Green’s seeding and sodding fertilizer are rich in phosphorus, a key component in root formation for the development of new seedlings. This product also contains humates that enhance the efficiency, availability, and exchange of plant nutrients to and from the soil.

Weed Controls

There are specific weed controls that cannot be applied before, during, or directly after seeding. Pre-emergent crabgrass preventers do not allow new grass seed to grow for three to four months after application. Jonathan Green Crabgrass Preventer plus New Seeding Lawn Fertilizer contains Siduron, also known as Tupersan. This product will prevent crabgrass and grassy weeds from germinating and lets you seed on the same day without injuring seedlings. Additionally, you cannot apply grass seed for three to four weeks after any broadleaf weed controls have been applied to the lawn. Apply broadleaf or grassy weed control products only after the seed germinates, and the grass is mowed three to four times.

Crabgrass Preventer plus New Seeding Lawn Fertilizer

Jonathan Green’s Crabgrass Preventer plus New Seeding Lawn Fertilizer feeds the lawn for two full months. It hastens seed germination thanks to a new seeding fertilizer formula that is packed with phosphorus. Phosphorus is a critical component in fertilizer analysis because it helps new grassroots grow deep and robust. This fertilizer contains Tupersan herbicide, which prevents crabgrass and other grassy weeds from germinating while allowing new grass seedlings to sprout without competition. Seed a new or existing lawn on the same day as spreading Crabgrass Preventer plus New Seeding Lawn Fertilizer.

Experiment 

By following this experiment, you can find out whether it was the grass seed, or another factor resulting in your grass seed growth.

Supplies
»  Cup or Jar
»  Paper towels
»  Water (tap water is fine!)
»  Jonathan Green grass seed
»  A warm, sunny windowsill

Steps
1. Place a paper towel inside the cup
2. Fill the cup with one inch of water
3. Sprinkle a large pinch of grass seed onto a paper towel
4. Place the cup on a warm, sunny windowsill
5. Check on it every few days, adding more water if necessary

If the seed germinates, you know that the grass seed is not the problem, but another variable has gone wrong. If it does not germinate, then don’t hesitate to contact one of our associates at the Gasper Garden Center. We are happy to help.

Review

When to apply each bag of the New American Lawn Programs

Learning how to apply Jonathan Green’s The New American Lawn Annual Program is easy with the yearly feeding calendars. Just choose the Standard or Organic Program Application Wheel below that best suits your needs. Then just follow the lawn and soil food schedules.

Wheel 1: New American Lawn Program Application Schedule

Wheel 2: Organic Application Schedule

If you prefer to apply only organic products to your lawn, use the Jonathan Green New American Lawn Organic Program. Eventually, we would like all customers to graduate to the Organic Program. However, if users have had many lawn weed problems in the past, we recommend using the New American Lawn Program above (wheel 1) for a few seasons. Once the weeds are under control, then switch to the New American Lawn Organic Program.