Why is my lime tree dying? | 8 Ways to save it

The top reasons why lime trees die are pest attack, not enough water or if they do not have the range of nutrients they need. Limes will need an all purpose fertilizer in Spring and Fall and regular water over the warmer months. Citrus greening is becoming a common problem that is causing the rapid die off of citrus including limes.

This article will explore the top reasons why your lime tree could be dying and what you can do to save it.

Top 8 reasons why you lime tree is dying and how to save it

Here are the top reasons why your lime tree is dying and what you can do to save it. These are easy solutions and will help you to grow a thriving lime tree at home.

1. Cold weather and frost

Lime trees love warmer tropical weather so if you live in a area that gets very cold winters or frosts your lime tree can be affected. A young lime tree can die off after one night of harsh frost so take care if you get extreme cold in your area.

To protect young or smaller lime trees from frosts planting them in a pot and moving them undercover in winter is an easy solution. For lime trees planted out in garden beds, use a tomato cage and drape some clear plastic over the top. This cage can be lifted on and off on frost nights to protect the lime.

2. Lime scale or aphids

Pests including scale bugs or aphids can attack a lime tree and cause it to die over time. Scale bugs are small, dark round bugs that will sit at the join between the leaf and the stem and suck sap from the tree. This can slow tree growth and cause mold growth on the plant.

Aphids are tiny green bugs which will land on new stem growth and also suck sap from the tree. Aphids can reproduce into huge numbers in a few days so keep an eye on them. Within a day ladybugs can come in to deal with the problem, eating aphids and getting rid of them quickly.

Eco oil sprays can be used to treat both problems if they become out of hand. I like to use my hose first to try to spray off as many bugs as possible if ladybugs have not moved in to deal with the problem. Neem oil will work to deal with these pests without the use of harsh chemicals.

3. Citrus greening

For those living in the US, this has been a problem that citrus growers have been dealing with for many years. Small insects called Asian Psyllids, spread a bacterial disease called Huanglongbing (HLB). This disease will stop the plant from transporting nutrient through the arteries through the leaves and stems.

This disease will show up as raised deep green veins on the underside of leaves, yellow leaf blotches or oddly shaped sour fruit¹. We are working hard to keep this disease out of Australia but there are many areas around the world that are affected by this problem.

Removing damaged leaves and treating with fungicide is the only way to try to beat this problem.

4. Not enough water

Lime trees need regular water particularly throughout the warmer months. Lime tree leaves will start to turn brown on the tips and will drop off the stems if the tree is not getting enough water. Lime trees that get too dry over the Winter or Summer months can die quickly so act fast.

Solution: Improve the soil with organic matter like compost and worm castings before planting. Surround your lime tree with mulch like sugar cane, straw or hay to keep the moisture in the soil for longer. 

5. Lack of nutrients

Lime trees can die off quickly if it is not getting the right nutrients including nitrogen. Lime trees need regular nutrients including more nitrogen in Spring and a range of nutrients in Fall.  Lime trees need regular access to nitrogen to continue to grow healthy leaves to feed the plant.

The easy way to solve this problem is to use a good quality organic fertilizer that contains a range of nutrients. You can use specialized citrus food, a regular pelleted chicken manure or even a vegetable fertilizer.

Give your lime tree an extra boost of nitrogen using a liquid fertilizer like fish emulsion over the warmer months. Add pelleted chicken manure in Spring and Fall which can be added 2-3 times over the three month period.

6. Poor quality soil

Preparing your soil before planting your lime tree is key to getting them off to the best start. Lime trees need free draining soil otherwise their roots can become too wet, rot and the plant will slowly die.

For those with clay or sandy soils, mix through compost and aged cow manure first. This will free up the soil and allow it to drain freely while still allowing the root system to grow wide and support the tree.

For potted lime trees, choose a premium potting mix which will have added slow release fertilizer and will drain freely. Once you have planted your new lime tree in a pot or garden bed, water it in well with diluted seaweed solution to improve soil microbe levels and settle the roots into the soil.

7. Top dressing lime trees

Providing nutrient to a lime tree over time can be done by adding a top dressing of compost and cow manure in Spring. Rake back any mulch and add a 1-2 inch layer of compost and cow manure mixed together.

Top this layer again with mulch and water it all in. This top dressing will feed the roots that sit near the surface of the soil. Lime trees will grow most of their roots near the top of the soil which are easily fed gently with a soil top dressing.

8. Trim dead leaves in Spring to refresh the plant

Once the risk of frosts have passed and the weather begins to turn warm in Spring any damaged leaves can be trimmed off using secateurs. It is important to wait until the weather warms as these damaged leaves will actually protect new growth from any future frosts.

Trimming off dead leaves in Spring will encourage your lime tree to sprout new leaves and stems to replace the old ones. Your tree will quickly be read to grow flowers and new fruit.

How to save dying lime tree

If your lime tree looks like it is dying first identify if there is any insect attack. Treat lime scale or aphids with horticultural oils for the next 2 weeks. Water the lime tree with a dilute mix of liquid nitrogen fertilizer and seaweed solution. Mulch the tree well with a 2 inch layer of sugar cane, bark or straw mulch and water it regularly.

This will give your lime tree the best chance of recovery. Old branches and leaves can be trimmed off once the cold weather has passed and you should see new shoots coming through in no time.

Why is my lime tree dying – Summary

Lime trees can die off quickly in very cold weather and frosts or if they are attacked by pests. Protect your lime tree in very cold climates and keep it watered and fed regularly to help it to be more resistant to pest attack.

I like to top dress all of my citrus with compost and aged cow manure in Spring to feed and protect their roots. You should have new growth and new limes in no time if you follow these steps.

Happy gardening.

References

ABC Australia, 2021, This tiny insect spreads a disease for which there’s no cure, Accessed 15^th September 2021, https://www.abc.net.au/news/2021-09-11/hlb-citrus-greening-biosecurity-australia-psyllid-finger-limes/100452594