Several months ago, I grew an avocado pit in a cup of water and planted it in a small pot. While the plant grew initially, it hasn’t grown any new leaves for some time. After an initial search online, I found there wasn’t a great answer. So, I did more digging. Here’s what I found causes leaves not to grow on avocado trees.
Avocado trees won’t grow new leaves if they have improper watering, sunlight, nutrients, or transplant shock. Generally, avocado pits that are first grown in water will have more transplant shock than those only grown in soil. Ideally, only water the tree when its soil is dry and provide compost and mulch.
So, while there are several reasons why avocado trees won’t grow new leaves, how can we tell which issue is causing it, and from there—how can we fix it? Let’s take a look.
Symptoms of under-watered avocado trees include poor leaf growth, as well as leaves curling, drooping, browning, and dropping.
In the beginning, leaves curl or droop to conserve moisture, but if left without water for too long, the leaves will begin to die (browning and dropping from the tree).
So, what’s the best way to water avocado trees?
Only water when the first 2-4 inches of soil is dry. You can check this by pushing a finger into the soil. The goal is to have soil moisture similar to a wrung-out sponge. Water at least 2 feet deep as over 90% of the tree’s roots are found at this depth.
Most roots are found close to the surface, with 90% or more of all roots located in the upper 60cm [24 inches].Martin Dobson, Arboricultural Advisory and Information Service
Additionally, provide 2 inches of compost and 4-12 inches of mulch. This amount might seem excessive, but fruit trees evolved in forests as understory plants and had plenty of fallen leaves and branches to maintain soil moisture and use as nutrients.
Compost not only provides valuable nutrients but feeds beneficial soil life and increases the soil’s richness. Every 1% increase in the soil’s richness or organic matter leads to 20,000 more gallons of water held per acre (source).
Mulch provides the avocado tree with dramatically reduced soil evaporation, soil temperature regulation, and nutrients once the mulch is broken down.
If the tree is still getting too hot and dry after providing compost and mulch, consider providing partial shade from the hot afternoon sun. A good way to tell is when the tree’s leaves start curling.
Over-watering also causes leaf growth to slow or stop, while other symptoms include leaves drooping, yellowing, and dropping. In the case of over-watering, these conditions are caused by the stress from the lack of oxygen in the soil.
Over time, waterlogged soil develops a type of water mold called root rot, which is what it sounds like—a disease that eats away at the tree’s roots. If not amended, root rot will kill the tree.
Just like under-watering, the best way to water avocado trees is to only water when the top 2-4 inches of soil is dry. This is the best way to prevent both under and over-watering!
However, if your avocado tree’s soil has poor drainage, then this needs to be amended first.
Even if you’re watering your avocado tree correctly, over-watering can still occur if its soil has poor drainage. This is especially common for avocado trees that are planted in heavy clay soil or those that have collapsed soil (typical of potted trees).
Here’s how to check for poor drainage and how to fix it.
Planted Avocado Trees
Check your avocado tree’s drainage by digging a nearby hole 1-foot deep, filling it with water, and measuring how quickly it drains. Just make sure to dig the hole outside of the tree’s drip-line (canopy). If the hole drains slower than 2 inches per hour, it has poor drainage.
If your avocado tree is already planted, it’s tricky to amend its soil as digging the tree up will likely result in transplant shock—potentially stunting or killing the tree.
Because of this, apply 2 inches of compost under the tree’s drip-line every 1-2 months. Over time, the compost will work its way down into the soil, amending and improving the drainage.
While you can also provide some mulch, too much will prevent waterlogged soil from drying. So, it’s best to avoid using mulch at this stage if possible.
On the other hand, if you have not yet planted your avocado tree (such as if you just bought it from a nursery), and your garden soil is draining poorly, it’s best to plant the tree on a mound of soil or in a raised bed.
For more information, check out my other post on working with clay soil and planting in mounds.
Once the soil is well-draining and feels like a wrung-out sponge, proceed with providing compost and mulch as directed in the above section.
Potted Avocado Trees
If you have a potted avocado tree, you can check its drainage by the feel of the soil. If the soil is sopping wet for more than 1 hour after watering, the soil needs to be amended. The goal should be soil moisture similar to that of a wrung-out sponge.
To amend a potted avocado tree’s soil, simply repot it with fresh potting soil. Because the pot naturally confines the avocado tree’s roots, there’s much less of a chance of transplant shock (compared to digging mature trees out of the ground).
Even if your potted avocado tree has root rot, repotting it will most likely save it. This is what happened to my Kaffir lime tree and it’s been thriving since!
Remember to repot your avocado tree into a larger pot every 3-5 years as the roots need more room to grow.
3. Lack of Sunlight
Generally, avocado trees require at least 6 hours of sunlight to photosynthesize properly. Without it, their leaves stop growing and can turn yellow. This is because the trees are unable to develop sugars for the plant and lack chlorophyll. Over time, this low energy leads to the plant’s declining health, which eventually dies.
Tips to Increase Sunlight
- Plant the avocado tree in a south-facing direction for maximum sunlight (north-facing if you live in the southern hemisphere)
- Plant the avocado tree along a south-facing wall to reflect more sunlight and heat onto the tree (some heat even persists into the night).
- Prune overstory trees that are blocking the avocado tree’s canopy from the sun. You can also prune the avocado tree itself to allow more light to reach the mid and lower branches. This new space also increases aeration from the sun and wind—discouraging disease from spreading.
4. Transplant Shock
If your avocado tree was recently planted or repotted, and it’s not growing any new leaves, it’s likely due to transplant shock. Transplant shock occurs when a plant is exposed to a new environment and has to establish a new root system.
Avoid transplanting avocado trees unless necessary as it can take up to 1 year for recovery.
To help avoid transplant shock, I like to plant with the following steps in mind:
- Have the new ground (or pot) prepared
- Remove as much of the tree’s current topsoil as possible, without damaging the shallow roots
- Grab the base of the tree’s trunk and wiggle lightly
- Using your other hand, scoop up and support the rootball
- Lightly place the tree in the new ground (or pot) and fill it in
- Make sure the soil is at the same level on the trunk as before
- Apply 2 inches of compost and 4-12 inches of mulch to the top of the soil
- Water generously and add more soil as needed
Transplant shock is difficult to avoid, but it’s definitely worth finding ways to reduce it.
For example, while sprouting avocado pits in water is a popular practice, it’s actually not the best method.
This is because avocado pits placed in water grow water roots, not soil roots. Once they’re planted in soil, they need to grow completely different roots (as well as get adjusted to the new soil environment).
To help solve this, TheKiwiGrower on YouTube tests the two main ways to grow avocado from seed (soil vs water) and determines which one works best.
Spoiler: planting the seed in the soil grows slower at first, but soon speeds past the growth of the seeds grown in water.
As a side note: keeping avocado trees in pots that are too small also results in a lack of leaf growth.
5. Improper Nutrients
Excess nutrients (caused by over-fertilizing) chemically burn the avocado tree’s roots. This stresses the tree, which results in discolored and dropping leaves as well as stunted growth. Normally, fast-release chemical fertilizers are the cause of over-fertilization as compost isn’t potent enough.
Lack of Nutrients
|Entire leaf is pale or yellow
|Dark green veins, rest of the leaf is yellowing
|Broadly pale leaves, foliage color looks mottled or smeared
A lack of nutrients also causes the tree stress, leading to similar conditions such as discolored leaves and stunted growth.
Insufficient nutrients are commonly caused by poor soils, leaching, and other conditions such as improper pH.
Nutrient leaching is when the nutrients seep too far down into the soil, out of reach of the plant’s roots (beyond about 2-3 feet). This normally occurs when soils have too much drainage or are over-watered. For example, sandy soils are notorious for their leaching.
Fortunately, most of these issues can be resolved by properly fertilizing avocado trees.
The Best Way To Fertilize Avocado Trees
The two main ways to fertilize your avocado tree are with fertilizer or compost. If you choose a store-bought fertilizer, aim for an NPK (nitrogen, phosphorus, and potassium) with double the nitrogen to phosphorus and potassium. For example, use a 6-3-3 NPK.
For compost, choose one with the highest quality and freshness if possible.
However, while chemical fertilizers have nutrients in quantity, they typically don’t have quality nutrients.
Even though chemical fertilizers are sufficient over the short-term, long-term they often short-circuit the nutrient exchange between the tree and its beneficial soil life (such as mycorrhizal fungi). This leads to dry and dead soil (AKA dirt) and overall decreased plant health.
Mycorrhizal fungi promote many aspects of plant life, in particular improved nutrition, better growth, stress tolerance, and disease resistance.Department of Biology, University of Fribourg, Switzerland
On the other hand, compost provides more than sufficient nutrients, increases water retention, and promotes healthy soils. Many gardeners are even finding that compost is replacing their fertilizers. Choose fresh and quality compost as its beneficial soil life and bacteria will still be alive.
Either one you choose—you can see my recommendations for both compost and fertilizer on my recommend fertilizer page.
Avocado trees need a soil pH of 5.0 to 7.0 (source).
While nutrients are important, they’re next to useless if the soil does not have a proper pH. This is because a slightly acidic pH is necessary to dissolve the nutrient solids in the soil and make them accessible for the plant’s finer roots.
Fourteen of the seventeen essential plant nutrients are obtained from the soil. Before a nutrient can be used by plants it must be dissolved in the soil solution. Most minerals and nutrients are more soluble or available in acid soils than in neutral or slightly alkaline soils.Donald Bickelhaupt, Instructional Support Specialist, Department of Forest and Natural Resources Management
Two good ways to check your soil’s pH are either by using a pH strip or a pH meter. I prefer using a pH meter since they’re affordable and easy to use. To see which pH meter I use and recommend, check out my recommended tools page.
If you find that your avocado tree’s soil is too alkaline (above 7.0) you can add acidic amendments such as coffee grounds, sand, and peat moss. On the other hand, if your avocado tree’s soil is too acidic (below 5.0), add alkaline materials such as wood ash, charcoal, or lime.
Additionally, cold and/or wet soils are not good at promoting nutrient uptake as the avocado tree will either be dormant during the cold or too stressed in wet soils.
After researching it, I found that my avocado tree pot wasn’t growing because the pot was too small. Once I repotted it to a larger container it started growing again!
I also made sure to apply 2 inches of compost and cover the soil with mulch (in this case, a shredded paper bag) to retain soil moisture.
Remember to only water when the soil is dry and provide best gardening practices and your avocado tree will thrive!