Much Easier Than You Think
Kaffir lime (Citrus hystrix) has many benefits, in both food and medicinal. Using its leaves is much common in cooking. Fruit is too sour to use but rind is also used in cooking. I love the scent of its crushed leaf and have been using them in my cooking. The oldest and biggest tree I have is around 20 years old.
It’s a pretty tough tree. Aside from being dragged up and down steps to the basement twice a year, it has been tipped sideways by strong wind many times. But, it’s still growing and pushing out new leaves every year. I have to prune it down every year so it can fit in the basement during winter. The rest of the limes are at various ages. I grow all Kaffir lime from seeds.
Kaffir lime is a small tree, native of Asia. Growing it from seed is not difficult even in a cold climate. Just take seeds from a ripe fruit, select the healthy looking seeds and discard the flat ones.
- Clean jell off the selected seeds and put them in seed starter medium. Put one seed per container so seedlings can be replanted in a bigger pot without their roots disturbed later on.
- Water, keep the container covered but leave a small gap for air to circulate then set it where it can get direct sun.
- If you have a heat mat, set the temperature at 80° F. Keeping the soil temperature constantly at 80° F will help the seeds germinate faster. Fertile seeds will germinate within three weeks. It may take a little bit longer without the heat mat. With one batch I didn’t use the heat mat but put the tray out on a cement floor under direct sun during the day and took it in at night. Some seeds may rot if the soil is too wet.
Two month old Kaffir limes I germinated this year
Clean, dry seeds can be kept in a dry airtight bag for a few years. The seeds I germinated this year are three years old.
- When you start Kaffir lime seedlings from dry seeds, soak the seeds for a couple of hours before putting them in the soil to soften the seed shell. The wet seeds will feel a little bit slimy but that is common for lime seeds.
- Once the seedlings develop a second set of true leaves, put them in a slightly bigger pot. The potting soil should be loamy and kept moist at all times. The key word is ‘moist’. Kaffir lime hates wet, soggy soil. Root rot can be a major problem. So, if keeping the soil ‘moist’ is difficult, stay on the dry side… much safer that way.
- If growing it in the house, keep it on the windowsill where it can get direct sunlight. Plant lights will do if there is no access to direct sun, but the light need to be on at least 8 hours a day.
- Kaffir lime can stay outside if the temperature is above 50° F both day and night. It can deal with nighttime temperatures between 40-50°F if the pot is situated close to the house.
- Change some of the potting soil every two years if possible. Loosen the old soil off the roots around 1/3 from the bottom but not more than half then put the plant in a new pot with fresh soil mix with compost at the bottom. Cover topsoil with some fresh soil and compost mix as well. Water thoroughly.
- Prune branches that crossed and rubbed one another. Nip the tip off a plant when it’s around six inches tall. It will start to branch out. Keep the pruned leaves in the freezer for future use in cooking.
- Feed monthly and keep soil moist. Stop feeding a month before taking the plant inside to over winter and start feeding again a month before bring it outside in spring or when new leaves start to bud.
New leaves will start to bud in late winter, an indication to start feeding - Even keeping Kaffir lime in an apartment, stop feeding in late fall and during winter time. Let it stay in semi-dormant stage until late winter. The plant will tell you when to feed. It will start sprouting new leaves, even in the house, when spring approaches. This is an indication to start feeding. Water it less in winter as well.
Spider mites are a known pest for houseplants, kaffir lime included. An indication is the web and tiny specks on the leaves. Leaves start to dry out and drop. If this problem occurs, give it a good shower both top and bottom of the leaves. Aphids like fresh new leaves, just spray them off with water. A spray bottle works very well for this.
The easy part, growing, is done. The difficult part is to refrain from eating it until it’s big enough to tolerate the leaves being picked off.
Petals and Wings 
Thank you for those great instructions. I love cooking Thai food, which often needs Kaffir leaves, so am interested in growing the plants.
Fresh ingredients always make food taste better. There is something special about fresh picked Kaffir lime leaves. As I have written, it’s very easy to grow. Let me know if there is anything I can do to assist.
You’re amazing. How do you have time for all you do?
It’s tough since I can do it only on my days off and early in the morning. But it’s something I love to do and it’s very satisfying when I see the outcome. I think, as an accomplished gardener yourself, you already know that. The way your garden looks, there is a lot of effort, love, caring, and all the time you have been putting in.
Nice article,
maybe you can help me, the leaves of my seedlings are not fragrant (only a fairly scent on some when I rub the leaves between my finger)
is it normal ?
Thanks
I don’t know how small your seedling is but young Kaffir lime leaves are not as fragrant as older leaves, even on an older plant.
Hey, what do you call a ripe fruit? Are the ones (green) sold in the store considered ripe?
The green ones in the store are not ripe however if any of them have a hint of yellow should work.
I am debating on whether to grow from seed or hunting down an established tree. How long would you estimate before you can start picking off leaves for use when growing from seed? Thank you, Karen
You should be able to pick some leaves after three years. I usually let them grow to around 8 inches tall before I start pruning. Logee’s sells them but they sell by pot size so I have no idea how big the plant is.
I’m want to buy your kaffir growing by seeding.
There is a nursery that see Kaffir lime, Logee’s. They offer very good service and plenty of tropical plants. However, I don’t know if they grow kaffir lime from seed.
Good info. Do you sell those seedlings you grow? If so, how much? Btw where are u located at?
Thank you. No, I don’t sell them, just gave most of them away to friends who garden and cook. At this point the seedlings I posted are too big to ship anyway. We are in New York.
So jealous of all your little (and big) KL trees! I one, bought as a 12″ sapling in Texas and carefully nurtured in/transplanted to central Mexico, where it eventually grew into a bush that provided as many leaves as my Thai food loving heart could want.
Unfortunately am now in India, have tried growing from seeds bought in the States, very little luck so far. And no plants to be had here. Anyway, this was a wonderful post, thank you. Link saved for the great advice for when I hopefully find a plant in the future that will be delivered here.
Hope you can find fertile seeds. It sounds to me like you had a problem with the seeds you used. It should be much easier to grow it in India since the weather is much warmer than the States.
Where can I buy seeds?
Asian grocery stores that sell fresh kaffir lime should have some. I have only a few years old seeds left and don’t think they will sprout. If I come across fresh seeds, will let you know.
I have tried to germinate around 15 seeds of kaffir lime but none sprouted so far. I did so on a heating mat with grow light over it, putting a thin foil over the seed tray with air holes but the seeds either stayed there, ungerminated, with their hard shell still intact, or they disappeared or had fungi on them.
When watering the soil before seeding I make sure the soil is completely wet and I let it drain, because a heating mat dries out the soil quickly.
I tried misting after planting seeds instead of watering but that dried out completely.
I tried soaking them in warm water for 4 hours and also tried not soaking them, for the ones I soaked I removed part or the whole outer shell (as some recommended it).
I know bad seed is possible, but I find 15 ungerminated seeds a bit much, I ordered more seeds from 3 other vendors but am out of ideas on what to do.
And yes I waited 3 to 5 weeks for them before checking.
Sorry for a late reply. I’ve been out of a commission for a few months. I hope this will help with your next batch. First of all, do not cover the seed tray with foil, plastic wrap is a better choice or you can use a small germination kit, with a clear dome cover. The clear dome or plastic wrap will keep moisture and heat in and still let light in as well. You don’t need to mist it. The seed will rot in soil that is too wet. The heat mat should be set between 75F to 80F.
It may not be your growing technique at all. If the seeds you get are not fresh, it won’t grow. If the seeds you received are flat instead of a little plump in the middle, it may not grow. Seeds culled from some hybrid types will not grow at all. Seeds from many hybrid vegetables and fruits will not germinate.
I will keep your contact info on file. If I come across a new seed batch, I’ll let you know.
I meant the thin plastic wrap for food yes, my mistake for using the wrong word 🙂
Unfortunatly I had one other seed shipment through a seller on amazon (Kabutto) whose seeds also did not germinate, I fear they were too old.
I knew about the flat seeds so I always filtered them out but even the very thick ones didn’t germinate. Either they rot or dissappear completely.
Sorry to hear that. As I mentioned earlier, I will let you know when I come across more seeds.
Should freshly germinating plants be put in the sun or just in a bright, warm location? Won’t direct sunlight harm young seedlings? I know that regular lemon seedlings should not be put in direct sunlight in the beginning.
If sunlight is recommended, how many hours a day?
I live in the middle east and the sun can be pretty brutal in summer.
Thanks 🙂
Sorry for a late reply. Kaffir lime seedlings shouldn’t be put in direct sunlight, filtered sunlight is fine. Six hours of sunlight is plenty. You should slowly introduce it to direct sunlight. However, you mentioned that you live in the Middle East, direct sunlight and dryness will not help even a full grown Kaffir tree. If you grow it inside the house, direct sunlight should be fine since there will not be added heat. Growing it outside, you should provide a little bit of shade.
Hello again, Bindu here from India. I have sort of a weird question. On a trip to the states a few months ago a very kind Thai store owner gave me a small branch from which I made a cutting. I started with one dual leaf, cut the top part in half, as per YouTube videos. Brought it back to india and it is leafing up well, but the top of the main stem (above where the original leaf was) is not growing, it is blackened at the top. Lots of new leafs below, but I don’t know how it will get taller if the stem won’t grow.
It looks like a very healthy, tiny dwarf kaffir plant, seven inches from the base soil to the top. Do you think it will ever put out a new main stem? If had been almost four months since I started the cutting. As I said, the plant looks really healthy and the leaves smell great, just not getting taller. I’ve looked for info online but can’t find any. Any thought would be really helpful!
Thank you for a very informative article. I would love to grow kaffir lime from seed but every thing I see offered has pretty negative. Where might I find viable seed or failing that, a seedling? I have a greenhouse and a large sun room.
Sorry for not replying sooner. Today is my first day back blogging. Seeds will be difficult to find but I’ll let you know when I come across them. Logee’s, a greenhouse in Connecticut sells small plants but I think, most likely from cuttings. Hope this helps a little.
Well, unfortunatly, both of my kaffir lime trees already died from root rot, despite changing the soil to equal parts of perlite, vermiculite and coco peat for good drainage and not watering them too much, but i think they must have had it for quite some time already. Even the key limes are dead, all 4 trees were grafted onto a winter-hardy rootstock and i think that’s the reason they’re so easily killed.
By a miracle I managed to acquire a single key lime seed which succcesfully germinated and is now slowly growing (but in the winter with a grow light and heating mat it’s still difficult) so i do think growing from seeds is best.
I haven’t been able to find fully developed kaffir lime seeds because the fresh kaffir lime fruits i was able to order online were not ripe yet and the seeds were all too thin and didn’t germinate
Agreed with you regarding growing from seeds. I have your contact info and will let you know when I have some seeds.
also I was not entirely clear in hte previous post, when I said in the sentence I bought a cutting and seeds recently, only the seeds came from ebay. The cutting came from the Netherlands, and was a proper made cutting from a larger plant, but it had been overwatered to survive transport I think and when I repotted it into my soil I watered it enough until it started dripping out (from what I read everywhere) but now the soil won’t dry out, but it does drain….
I found some Kaffir Lime seeds on eBay and bought them. They sprouted fine, but they and some Orange Jasmine seeds (from the same person) don’t seem to be growing after sprouting. They are just staying the same size, no new leaves in the last few weeks. Is this normal?
Sorry for the late reply. Working from home consumes a lot more of my time than usual. Both Orange Jasmine and Kaffir Lime are in the same Citrus family so their needs are similar. They need a lot of sunlight and heat to grow well. When they are small, they seem to stall a little bit but once they grow past two years old, they will be fine. Hope your citrus are fine now.
When I planted kaffir lime seeds I gave them much sun, they ended up sunburnt.
Kaffir limes require a temperature around 22°C and morning sun for optimal growth, anything more and the seedlings will die, like mine did.
I agree with you that morning sun is the best for seedlings. Also, when I said sunlight I didn’t mean the seedlings should sit under midday sun but place them somewhere that they can get sunlight and some heat from the sun. My seedlings are under the patio roof but near the edge so they get indirect sunlight as long as the sun is still up. My full grown Kaffir lime trees, however, stay outside without any shade providing that I put mulch on top of the potting soil to keep the soil moist & cool.
I’m glad you found good seeds. I was actually about to email you regarding the seeds as I mentioned to you in our earlier correspondence. I haven’t been blogging since earlier in the year, Instagram takes less time from my work from home hours. As our environment is slowly working toward a ‘new- normal’, if you still want them, I can send some to you as well.
I definitely want them because none of the seedlings survived unfortunately.
If you like we can discuss details via email further 🙂
I just emailed you.
I have them under a wire frame that is covered with shade netting (the wire frame is to protect them from critters), day time temps have been upper 70’s to 80’s, night time has been dropping to the 50’s though. They really don’t seem to be doing anything.
Give them some time. The first two years are difficult but after that they are hard to kill.
Great to meet you! 🙏
Very nice to meet you too. Will email you shortly.
What is the trick in being able to keep your oldest Kaffir tree alive and growing in a pot for 20 years, which is amazing? Do you regularly pH check the soil in the container or any other tips, like the fertilizing schedule, potting soil amendments, etc?
I repot them every two or three years. I use organic potting soil, add a little sand in the soil too as the potting soil can be a little ‘boggy’. Fertilizer is used once a month from spring on, but not in winter. Mulch to keep the top from drying out. Water less when they are inside the house during winter; I let the leaves start to curl a little (show dryness), then I water them.
They are fine when they are outside in summer. In winter I have to look for spider mites, aphids and scales. I spray them with diluted Neem oil.
Hope this helps.
I see that you used jiffy peat pellets to germinate and sprout your kaffir lime seeds. Is that your preference over seed starting soil? I have both and my seeds just arrived, so want to increase my odds as much as possible. Thanks for the informative site!
I used the ‘Jiffy peat’ pellets because I didn’t want to disturb the roots when I replant the seedlings in the larger pots. However, many times I still have to tear the mesh off. If you have the smallest size of compostable pot, that’s the best to use. You can put the whole pot under the soil when you replant the seedling. It composts much faster than the Jiffy.
Thanks for the reply. So far none of the seeds in the 6 jiffy peat pots have germinated, but I will give them some more time. I managed to get 3 to sprout (2 in seed starting mix and 1 in potting soil) and they are over an inch tall now. My germination rate is only 15% which seems low. I see on some other sites that after soaking dry seeds for a few hours, people peel off one side of the seed before planting them to give the sprout a head start to emerge. Is this something you have done, or do you plant the seeds as is?