At one point, some basil plants I was growing ended up getting a lot bigger than I expected, so it made me wonder how big basil plants usually get, so I decided to do some research.
As I was doing my research, I created a table that shows the average height and leaf size of 22 basil varieties, including the most popular ones and a handful of less common ones.
As you will see in the table, there is an enormous difference in both how tall different basil varieties get and how large the leaves get, with some varieties growing up to 3 feet (90 cm) tall and others only reaching 6-8 inches (15-20 cm) in height.
To make it as easy as possible to find the basil variety you are interested in, I have put 5 of the most common and popular variest at the top of the table and then arranged the rest of the varieties alphabetically.
| Variety | Height (Inches) | Height (centimeters) | Leaf Size |
| Genovese Basil (Sweet Basil) | 24-36 inches | 60-90 centimeters | 2-3 inches (5-7.5 cm) |
| Lemon Basil | 12-18 inches | 30-45 centimeters | 2 inches (5 cm) |
| Purple Basil | 18-24 inches | 45-60 centimeters | 2-3 inches (5-7.5 cm) |
| Cinnamon Basil | 18-30 inches | 45-75 centimeters | 2-3 inches (5-7.5 cm) |
| Thai Basil | 12-18 inches | 30-45 centimeters | 1-2 inches (2.5-5 cm) |
| African Blue Basil | 18-36 inches | 45-90 centimeters | 2-3 inches (5-7.5 cm) |
| Boxwood Basil | Up to 12 inches | Up to 30 centimeters | 1/2-1 inches (1-2.5 cm) |
| Cardinal Basil | 24-30 inches | 60-75 centimeters | 2-3 inches (5-7.5 cm) |
| Christmas Basil | 10-12 inches | 25-30 centimeters | Up to 2 inches (5 cm) |
| Emerald Towers Basil | 24-36 inches | 60-90 centimeters | 2-3 inches (5-7.5 cm) |
| Greek Basil | Up to 8 inches | Up to 20 centimeters | 1-2 inches (2.5-5 cm) |
| Green Ruffles Basil | Up to 24 inches | Up to 60 centimeters | 4-6 inches (10-15 cm) |
| Holy Basil | Up to 24 inches | Up to 60 centimeters | Up to 2 inches (5 cm) |
| Italian Large Leaf Basil | 24-30 inches | 60-75 centimeters | Up to 4 inches (10 cm) |
| Lettuce Leaf basil | 18-24 inches | 45-60 centimeters | Up to 5 inches (12.5 cm) |
| Lime Basil | 16-24 inches | 40-60 centimeters | 3-5 inches (7.5-12.5 cm) |
| Mammoth Basil | Up to 16 inches | Up to 40 centimeters | Up to 4 inches (10 cm) |
| Minette Basil | 10-12 inches | 25-30 centimeters | 1/4-1/2 inches (1-2.5 cm) |
| Pistou Basil | 6-8 inches | 15-20 centimeters | 1/2-1 inch (1-2.5 cm) |
| Siam Queen Basil | 10-24 inches | 25-60 centimeters | Up to 4 inches (10 cm) |
| Spicy Globe Basil | 6-12 inches | 15-30 centimeters | 1/4-1/2 inches (0.5-1 cm) |
| Summerlong Basil | Up to 12 inches | Up to 30 centimeters | 1-2 inches (2.5-5 cm) |
As you can see, there is a significant difference in how big some of these basil varieties get, so it is important that you are aware of the size of the plant before you pick one to grow.
Individual basil plants usually don’t get very wide compared to how tall they get, but since basil plants are often grown relatively close to each other, they often appear dense and bushy, and it can be difficult to distinguish between individual plants without looking at the stem close to the ground.
The table above shows the average size of 22 basil varieties, but if given the best possible conditions while being fed with a generous amount of the right nutrients, certain basil varieties can get even larger as you will see later in this post, but first, I will help you determine how much space you need to grow basil.
How Much Space do You Need to Grow Basil
As mentioned above, basil usually requires more vertical space than horizontal space. However, that depends on what variety you are growing and, more importantly, how many plants you plan on growing.
Basil plants should be planted in small groups of 3-5 plants and with 12-16 inches (30-40 cm) of spacing between each group. This allows the basil plants to grow for the whole season while still allowing air to flow between and around all the plants.
While basil plants can be grown relatively close to each other, they should not be overcrowded as that will affect the roots’ ability to grow and the plants’ ability to obtain water and nutrients efficiently.
Largest Basil Plant Ever Measured
As I was doing my research for this post, I got curious and wanted to know just how large basil plants can get, and I stumbled upon a world record.
According to Guinness World Records, the largest basil plant ever measured reached a height of almost 11 feet (3.34 meters). It was grown by Anastasia Grigoraki in Greece in 2012. Unfortunately, the source does not mention which variety of basil it was.
Read My Complete Guide to Growing and Caring for Basil
I have written a thorough guide where I cover all parts of growing your own basil including choosing a variety, sowing the seeds, the best growing conditions, pruning, propagation, harvesting, storing, solving various problems, and a lot more. You can find the article on this link.
