It is possible to grow citrus trees in the UK and Kaffir Lime Citrus hystrix is no exception.
To grow kaffir lime trees from seed you will need to use a heated propagator and keep the seedlings in a temperature controlled environment. When they are old enough to plant into larger pots you can take cuttings and propagate from them from around the second year. You are not growing for the bitter fruit but the leaves and rind of the limes.
A conservatory will help you to grow these citrus trees but just bringing your trees inside and cutting back on watering during Winter will be a big help.
How To Grow Kaffir Lime From Seed
You can purchase Kaffir Lime seeds here. They arrive dried, but when you soak them be prepared for them to feel slimy and slippery. This is perfectly natural when growing citrus from seed. You can use fresh seeds harvested from your existing tree. They must be cleaned off first to remove the jelly that will surround them. In the UK it is unusual to have a market where you can buy fresh kaffir limes, but if you do find one choose the plumpest one and harvest from there!
Step-By-Step To Growing Kaffir Lime From Seeds
- Prepare your pots with plenty of drainage and a loamy soil mix. Kaffir lime wants to be warm and moist not soggy and cold. So plenty of drainage and warmth. If you live in a cooler area you can plant as a houseplant through the year but use a heated propagator and lamp.
- When using harvested fresh kaffir lime seeds, remove the jelly surrounding the seeds. If using the dried ones from a reputable nursery, soak overnight in warm water. Expect either seeds to still have a slippery feel to them. The plumper the seeds are the better and they should be so plump as to be just ready to crack open for germination.
- Push the seeds around 1/2 an inch into the soil mixture. Cover and sprinkle with water. Leave your kaffir lime seeds in a warm spot and make sure they are moist at all times. Good drainage is essential, even for the seeds and germination will not take place in soggy soil. the temperature should be at around 70-80 degrees at all times. This means a heated area is essential in the UK.
- Kaffir lime tree seeds take around 12-15 days to germinate. Once leaves are showing sunlight and moist soil are an absolute must. In USDA zones 9 and 10 you will be fine in pots outside as long as you can protect them from harsh, drying winds. In the UK and USDA zones below 9 kaffir lime will be a great houseplant which spends Summer months outside.
- When you have the second showing of true leaves you can repot your kaffir lime seedlings. Do not be tempted to go straight into a large pot, work your way up. Keep the moisture and warmth up through this delicate time. Your mature tree will be far more robust but the seedlings need that extra bit of care!
Care and Tips For Growing Kaffir Lime Trees
During the Summer months your kaffir lime tree will grow significantly, especially the first Summer. So give it a good quality liquid citrus feed, Baby Bio do one available here. We do this every two weeks whilst the tree is outside in its pot. We are based in the UK, so the equivalent in USDA zones would be 8 and below.
TOP TIP – First feed is the very day you move it outside. If you plan on planting kaffir lime in the soil, dig through some well rotted manure to enable better drainage.
When you keep your kaffir lime tree in pots make sure to water before it dries out! In hotter climates this can mean a permanent mulch on the surface of the pot to reduce evaporation from the sun. Water to the base of the tree and avoid burning the leaves. If you have planted directly watering will need to be less urgent as this sub-tropical tree can find it’s roots spreading quickly. There is a school of thought that leans towards feeding citrus trees with Epsom salts and we have seen good indication that a foliar spray works very well.
Avoid temperatures below 5 degrees Celsius. Kaffir lime is a subtropical plant and therefore will cope with a lot, but not extreme cold. Bringing it indoors is a great way to protect it, as long as your conservatory will not drop below 5! Kaffir lime trees do make a great houseplant too though, so long as they get sunlight.
TOP TIP- Kaffir lime trees will need a dormant period. Even if you live in USDA zones 9- 10 and have planted outside, stop the fertilizer for three to four months over Winter. If you have them as a houseplant do the same and even reduce the watering a little. The recovery time for plants is not to be underestimated as when they do then awake from their enforced Winter they are ready to go again with a renewed vigor.
Harvesting Kaffir Limes and Leaves
Do not rush to harvest leaves from your seed grown kaffir lime tree. Perhaps the second year it can take a few being harvested, but not in the first year. Kaffir lime will hopefully fruit in around the tenth year. So no harvesting limes until year 10 if you have grown from seed.
Not a problem if you are after the gorgeous leaves to use in cooking, but if you want to use the rind of the limes sooner you may want to look at buying a potted plant from a reputable specialist online nursery. Let’s face it though, gardening and growing our own food isn’t always about a quick return on investment.
Growing A Kaffir Lime From Cuttings
Growing trees can be a long process, but kaffir lime trees are really unusual and lovely to look at whilst they are growing large enough to harvest. I would recommend a continuous cycle of starting from seed and then a few years later starting from cuttings. This means you will have a few immature trees, a few seedlings and a few mature trees ready for harvesting at all times.
One way to start your journey is through growing from seed, another slightly faster way to get started is to purchase a more mature tree and propagate through cuttings initially and then through seed once the tree is fruiting. To buy a 3 litre potted tree in the UK we would recommend going with a reputable online nursery like Suttons, here.
Step-By-Step Guide To Propagation Of Kaffir Limes
- Wait until your kaffir lime tree is mature enough to have cuttings taken. This is just to stop the mother plant from dying. We do not recommend taking from a tree less than a year in age.
- There will be a natural place to snap the leaves from, you can see from the image above that it forms a heal when it snaps off. By placing them immediately into water you will find roots appear quite naturally.
- Make sure to change the water daily, keep the leaves in sunlight for as long as possible each day.
- If any signs of damage or decay appear on any cuttings remove them immediately and change the water, discarding the damaged cutting.
- Around the three week mark you should have firm roots appearing. We like this process as you can physically see it happening, but you now need to carefully plant these delicate roots into soil. Alternatively you can propagate kaffir lime cuttings directly into soil.
- Using the same method with your snapped off kaffir lime cuttings, push them into the soil and keep warm, moist and in sunlight. Cover with a clear plastic bag to enable the moisture levels to stay the same.
- After around 3-4 weeks of watering and watching for mold or black marks give the kaffir cuttings a gentle tug test. If it offers resistance it has taken root.
- Once your kaffir cuttings have taken root they will need to be kept watered and in sunshine until new leaves have emerged. Then you can transplant to a larger pot and start to feed with a liquid feed every fortnight.
- You will see faster results growing from propagation than from seeds, in that you can harvest leaves within a year this way. It will still be around the ten year mark before you can harvest the fruit though. It is important to note that kaffir limes are horrible to eat! Way too bitter for the palate, but the rind is useful in Asian cuisine. We have a little guide on drying herbs available here, including how to dry kaffir lime leaves.
Pests, Problems and Pruning
- Aphids are a big problem on your new leaves. Aphids excrete honeydew, which is sticky and encourages black sooty mold, which they then eat. However the mold is really harmful to your tender leaves and we have seen it decimate trees, putting them back for a year at least. A great bonus of growing your own kaffir lime is that it is organic so now is not the time to rush to buy chemicals. You will gain a lot of satisfaction from watching ladybirds come along and eat the aphids so we recommend buying in some from Amazon, here and then just enjoy watching nature at work!
- Spider Mite can affect all houseplants. A simple method is to wash the leaves as and when the problem seems to arise. Spider mites in kaffir lime looks like black dots, webs and leaves drying up and falling off. Often mistaken as the tree needing more water, and then ‘solved’ by drowning the roots! So if you see leaves curling look for the spider mites first.
- Over watering is always going to be a risk with houseplants. Yes kaffir lime is a subtropical plant and therefore likes a moist soil, but this does not mean waterlogged roots. Use pebbles in the drip tray, then sit your pot on to the pebbles. This means any water that drains through will still be gathered and not damage your floor, but it wont mean the roots are sat in water.
- Pruning is an area where we have seen a wide range of advice. You will want to prune to keep it compact for a houseplant. Do this in Late Summer. But if you are growing outside all year round leave your kaffir lime tree to do it’s thing. Some people advise pruning flowers to allow for a longer flowering period, but if you want fruit just dead head as and when. Strong winds will knock your potted plants and I have had to perform a mid season trim on more than one occasion, but no ill effects were seen. The more mature the tree is the better it will survive pretty much anything.
If you like cooking with fresh ingredients then growing your own is the way forward. There are so many wonderful recipes for kaffir lime leaves that you can’t not be tempted to get your own tree. I hope that we have tempted you to grow a few more than one as well!
- We have a lot of inspiration for exotic herb growing so check out our other articles and hopefully you will be tempted!
- For those who have the patience for kaffir lime trees you may also have the patience for the fabulous Persimmon tree. Really worth the wait as the fruit tastes like a cross between mango and apricot but has the smooth texture of custard!
Many thanks and good luck!