The fragrant kaffir lime has a relatively short germination period.
But, because kaffir lime trees are subtropical, they require high humidity and plenty of sunlight to grow properly.
However, growing them is rather easy.
You just need to keep them in a warm and moist environment throughout their lives.
This article will tell you all you need to know about growing kaffir lime from seed.
Can I Grow Kaffir Lime Where I Live?
Kaffir lime trees grow best in hardiness zones 9 -12, being a subtropical plant species.
So, unfortunately, few places in the United States are hospitable for growing kaffir lime.
And temperatures below 60 degrees Fahrenheit (16 C) can kill or damage kaffir lime trees.
Thus, if you live in an environment with hot summers but winters with temperatures below 60 degrees, you need to bring your plants inside during colder seasons.
However, greenhouses are ideal for keeping humidity and heat consistent for your kaffir lime, so you can grow them inside one if you live in a cool area.
Kaffir lime trees also require high humidity and sandy, well-drained soil.
Additionally, they have to have at least six hours of full sun per day.
What Do I Need Before I Start?
Before you begin planting your kaffir lime from seed, you will need the following:
- A bowl
- Warm water
- Sandy soil
- A heat mat
- A plastic sheet (to cover the pot)
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3 Steps to Grow Kaffir Lime From Seed
Step One: Prepare Your Soil and Plant Your Seeds
First of all, your soil should be loamy – the ideal composition being part sand, silt, and clay.
This soil will drain well and prevent root rot while retaining enough moisture for seeds to thrive.
If using freshly harvested seeds directly from ripe fruit, plant the seeds into the soil, making sure only to place one seed per container.
Keeping your seeds spread out helps when you transplant seedlings into larger containers because you won’t damage the roots.
Conversely, if you’re using older seeds, soak them in a bowl of warm water for 2-3 hours to soften the seeds’ hard outer shells.
Then, you can plant them.
You should also know that kaffir lime seeds will remain fertile for 2-3 years, sometimes longer, if dry and stored in an airtight bag.
So, if your seeds are older than three years, you should get new seeds.
Next, after planting the seeds, you need to water each container well and cover it with plastic.
Then, leave a small gap or hole in the plastic for adequate air circulation.
Lastly, place your pots on the heat mat and set the temperature to about 80 degrees Fahrenheit (27 C).
If you don’t have a heat mat, you can place your pots on concrete or asphalt in direct sunlight.
And then check every few days for signs of sprouting.
Generally, most seeds will sprout within three weeks.
Step Two: Care for Your Seedlings
The most important thing to remember when growing kaffir limes is to keep the soil moist, as they will die if you allow them to dry out.
Additionally, kaffir lime trees need at least six hours of direct sunlight a day, especially when they’re growing.
Thus, if you’re keeping them indoors or in a greenhouse, use plant lights and turn them on for around six to eight hours a day.
Then, once your seeds have sprouted, remove the plastic, and take the containers off the heat mat.
And when the seedlings have sprouted two sets of leaves, move them to larger containers.
Finally, prune the branches when they intersect and on the top to make the tree fuller.
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Step Three: Maintain Your Kaffir Lime
If you live within the correct hardiness zones for kaffir limes to thrive and want to plant them in the ground, make sure you put them somewhere that gets direct sunlight.
Conversely, if growing kaffir lime indoors, you can allow the plant to go dormant during the fall and winter.
Then, in late winter or early spring, you’ll notice new leaves sprouting.
Once this happens, you should begin fertilizing the plant again.
And overall, you should fertilize indoor kaffir limes every month during the spring, summer, and early fall.
On the other hand, for outdoor kaffir limes, it’s best to fertilize them once a year, usually in the spring.
You should also remember to wait until your kaffir limes are at least three years old before picking off the leaves to use in cooking.
Younger kaffir limes won’t easily tolerate the removal of their leaves, and you might damage them by picking off leaves too early.
Plus, immature kaffir limes leaves don’t have the fragrance and flavor for which kaffir limes are known.
Why Should I Grow Kaffir Lime?
While the kaffir lime fruit is generally too sour for consumption, people often use the mature leaves in Thai cooking.
Kaffirs are also quite fragrant and add a unique flavor to any dish.
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To recap, you will need to perform the following steps to grow kaffir lime from seed:
- Harvest or buy kaffir lime seeds
- Soak the seeds in a bowl full of warm water to soften the hard outer shell and to speed up germination (if needed)
- Prepare containers with sandy, moist soil mixture.
- Plant one seed per container to make it easier to transplant into larger containers as the seedlings mature
- Water thoroughly, then cover each container with plastic. Leave a small gap for air.
- Place your containers on a heat mat and set the temperature to 80 degrees Fahrenheit (27 C)
- Once the seeds sprout, remove the plastic and take your container off the heat mat. Keep the plant moist and warm.
- After seedlings develop two sets of leaves, transfer them to a larger container.
- Keep the soil moist but not soggy – overly wet soil can lead to root rot
- Kaffir limes planted from seed can take 2-10 years to bear fruit