How Fast do Bass Grow? (Largemouth vs. Smallmouth)

Bass fishing is an exhilarating and exciting sport, there are thousands of bass fishing tournaments held every year in search of the biggest fish, but did you ever wonder how fast a bass fish grows? How long does it take for a bass to grow to trophy size?

How fast do bass grow? Bass grow 8 inches their first year in Southern states and around 6 inches in Northern states. They will grow another 3-4 inches their second year, another 2-3 inches their 3rd and 4th year, and then grow usually only an inch per year starting at year 5. Females bass are larger than males.

Bass experience the largest percentage of growth in their first year, mainly because their food sources are smaller in size and so there is less competition from bigger fish. They will continue to grow an additional 2-3 inches per year until around age 5 when their growth slows to 1 inch per year.

Growth rates vary depending on the type of bass as well. This article will focus on largemouth bass and smallmouth bass specifically.

Do Largemouth Bass and Smallmouth Bass Grow at the Same Pace?

Largemouth bass grow much faster than smallmouth bass due to their love of warm water.  Largemouth bass seek out warmer waters in lakes and ponds while smallmouth bass prefer to be closer to the bottoms of lakes where the water temps are cooler.

Warmer water can be found in shallow parts of a lake and near the surface. Smallmouth bass will be found in the deepest part of the lake during warm months or near a cooler water source entering the lake.

Smallmouth bass prefer colder temperatures and are mostly found in Northern waters so their growth rate will always be much slower than largemouth bass and will stay relatively constant year after year. While largemouth bass can be found in 48 states because of their preference of warmer water and will always grow much quicker.

On average, largemouth bass will be around 12 inches by the end of its 2nd year while it will take 3-5 years for smallmouth bass to grow 12 inches. 12 inches is the legally harvestable size in states that have a minimum recreational size limit of 12 inches.

Why Do Bass Growth Rates Vary from Year to Year?

Having an ample food supply is key and will have a major effect on fish size. While baitfish are a big part of a bass diet, studies have shown that crawfish are the preferred food source for the biggest and fastest-growing bass.

Bass will grow faster in newer ponds than they would in lakes because there isn’t high competition from bigger fish.

In an established body of water, the growth rate of a fish will taper off due to competition from other large fish that limits their ability to grow at a faster pace.

In larger lakes, the ample space and food sources will make room for larger populations of bigger fish while a small pond will limit the possibility of many large fish.

Water temperatures greatly affect bass growth rate, as well.

Since the optimal water temperature for bass growth is between 81 and 86 degrees Fahrenheit, and summers will vary widely from year to year, a fish will vary in added weight and length.

In the Northern states, water will have more days at these optimal temps than other years, which can lead to faster-growing fish some years and slower growth in other years.

In general, bass fish will grow at a much slower rate in Northern states, while states in the South will always have much longer growing seasons, leading to much larger bass.

Smallmouth bass prefer colder temperatures and are mostly found in Northern waters so their growth rate will always be much slower than largemouth bass and their growth rate will stay relatively constant year after year.

Can Anything be Done to Increase the Size of a Bass?

Many pond/reservoir managers introduce threadfin shad to the water to boost bass size. They are small, bite-sized fish for bass.

These fish are primarily pelagic, meaning they inhabit the open water, rather than the areas near the bottom of the shoreline, and are the proper size for bass to feed on. Bass grow faster because of the threadfin protein value.

This practice is most practically done in Southern states since Threadfin Shad are cold intolerant and, generally, cannot handle water temperatures below 40 degrees Fahrenheit. But if you had some money to burn you could add them to Northern lakes in the Spring when the water temperature rises above 50 degrees but expect them not to survive the winter.

How do You Find the Age of a Bass?

It is vital to figure out the age of a fish when trying to calculate its growth rate.

Calculating the age of a fish is very similar to aging a tree, it is done by counting the number of growth rings on a fish scale. Only the wide growth rings are counted, these rings are called annuli. These wide growth rings represent the summer months in the life of fish, they are wide because the vast majority of growth happens in warm water during the summer.

Every year in a fish’s life will have an annulus which is then preceded by a cluster of rings very close together which represents the winter months. Each cluster of annuli represents a year.

In order to count the annuli (growth rings), to establish the age of a fish, scales must be removed from the fish. To do this, use tweezers to remove 3-5 scales from behind the pectoral fin of the fish.

After the scales are dry use a microscope to count the rings on the scales to determine the age, focusing on the clusters of largest growth to determine a year at a time. Using scales to calculate the age of a fish is safe for the fish and does not harm it.

How Long does it Take for a Bass to Grow to Trophy Size?

Most anglers would consider a fish larger than 5 pounds to be a big bass and a trophy winner. Weather and food sources vary from year to year but on average an 18 or 19-inch bass will weigh in at around 5 pounds. And based on bass growth charts, a 5-pound bass will be at least 3 years old in Southern states and at least 4 years old in Northern, colder climates.  The larger the body of water, the bigger the possibility of catching a large bass will be.  More food sources and more room to roam means less competition and bigger, heavier bass! And obviously, using the right lure helps immensely.

Recap: How Fast do Bass Grow?

In conclusion:

• Largemouth bass will be larger in length and weigh more overall in southern states because the water temperatures are optimal for growth for longer stretches of the year.
• Fish in Southern states will always grow faster and bigger than bass living in Northern waters.
• Smallmouth bass will always grow at a slower rate than largemouth bass because they prefer cooler water temperatures which will keep them smaller and growing at a slower rate.
• The vast majority of fish growth occurs in the first 4 years of life and tapers off starting at age 5 due to competition for food from other large fish.