Pineapples are tricky to grow and I read some gardeners have a hard time with curling leaves on pineapple plants. Unfortunately, there’s only a bit of information out there on this condition, so I did some more research. Here’s what I found.
Pineapple plants get curling leaves from fruiting, under-watering, hot weather, or improper nutrients. When a pineapple plant fruits, it’s normal for the main plant to die, and a new plant grows from its shoots. Ideally, only water pineapple plants when their soil is dry and provide compost, mulch, and partial shade.
So, while pineapple plants get curled leaves from several causes, how can we tell which issue is causing it, and from there—how do we fix it? Let’s take a closer look.
1. Dying After Fruiting
After a pineapple plant fruits, it’s perfectly normal for the main (or mother) plant to die off. During this process, the pineapple plant gets curling, yellowing, browning, and dying leaves. In its place, the new shoots growing from the base will grow into new plants.
This method of regrowing from shoots is highly useful when propagating pineapple plants and is very similar to how banana plants grow.
So, if your pineapple plant has finished fruiting recently, and you noticed the top most leaves curling and dying off, know that this is normal and you don’t need to do anything different.
However, what if your pineapple plant hasn’t fruited recently and its leaves are still curling? What’s the next most likely cause?
The most frequent cause of curled leaves on pineapple plants is under-watering. You can tell if your pineapple plant is under-watered if its leaves are curling, drying, and turning brown starting at the tips. Another sign is if the top few inches of soil is bone dry.
So, what’s the best way to water pineapple plants?
Ideally, only water pineapple plants when the top 2-4 inches of soil is dry. You can check this by pushing a finger into the soil, under the pineapple plant’s leaves. Watering in this way prevents both under-watering and over-watering. Additionally, provide 2 inches of compost and 4 inches of mulch to retain moisture and protect the soil.
Compost provides valuable nutrients for the pineapple plant (as well as beneficial soil life) and increases the richness of the soil. For every 1% increase in the soil’s richness, 1 acre of soil can hold an additional 20,000 gallons of water (source).
Mulch is equally as important as compost as it protects the soil from drying out and eroding in the sun and wind, which also keeps the beneficial soil life alive. It also significantly reduces evaporation.
When applying compost and mulch, make sure to keep them at least 3 inches away from the stem of the pineapple plant as the moisture can encourage mold on the stem. Reapply compost every 1-2 months and mulch every 3-6 months.
However, if your pineapple’s soil is poorly draining, we’ll need to address this first before using compost and mulch.
How to Amend Poor Drainage
Generally, with poorly draining soils, potted pineapple plants can simply be repotted with fresh potting soil.
On the other hand, planted pineapple plants are a bit trickier. Typically, the best way to amend the soil for planted pineapples is to minimally water it and provide lots of compost—letting it naturally work its way into the soil over time.
But if you’re working with heavy clay soil, its poor drainage and alkalinity will likely lead to growth issues for the pineapple plant. It’s also harder to amend. In this case, it’s better to plant it on a mound of soil and mulch on top of the clay, instead of digging into it.
The goal is to have soil that drains after about an hour and has the same moisture as a wrung-out sponge.
For more information about clay soil and planting in mounds, check out my other post: Can Fruit Trees Grow in Clay Soil (& How To Plant Them)?.
Once your pineapple plant has properly draining soil, proceed with the above steps of providing 2 inches of compost and 4 inches of mulch.
3. Extreme Heat
To help prevent curling leaves, avoid exposing your pineapple plants to temperatures over 100ºF. While pineapple plants are natively from the tropics and can handle high heat, they also evolved as an understory plant with access to some shade.
Additionally, they need proper watering to help keep themselves cool.
Pineapple plants cool themselves by sending moisture from their roots to their leaves and through a process called transpiration.
Much like humans, plants breathe and release moisture when hot. For plants, this is called transpiration. However, when the climate is too hot and dry, transpiration and root moisture can’t effectively keep up to cool the plant and its leaves.
As a result, the pineapple plant’s leaves curl and brown at the tips. Over time, the entire leaf will brown and die, followed by the whole plant.
Hot Weather Tips
Here are some tips that will help your pineapple plant survive warmer weather and the occasional heat spell:
- Compost – apply 2 inches of compost to not only provide nutrients for your pineapple plant but to hold more water in the soil and help prevent drought stress.
- Mulch – similar to compost, mulch goes a long way in water retention, but also offers other benefits such as shading and insulating the soil—regulating its temperature. Provide a minimum of 4 inches of mulch for best results.
- Shade – shade further protects the plant’s leaves, roots, and soil from the heat. Some ideas to create shade for your pineapple plants are large umbrellas, shade sails, trellises, or other plants.
In extremely hot and dry weather, pineapple plants benefit greatly from partial shade. This is especially true for protection against the west, afternoon sun as it’s the hottest.
To see which plants are good to shade and grow next to pineapples, check out my recent post: The Top 10 Companion Plants for Pineapple.
4. Improper Nutrients
Pineapple plants that are over or under-fertilized become stressed, leading to curling, yellowing, and browning leaves. A lack of nutrients causes deficiencies (zinc deficiency is common in pineapple plants) while nutrient potency from excess fertilizer causes the pineapple’s roots to burn.
For best results, use a quality fertilizer as directed, or 2 inches of compost every 1-2 months.
Chemical Fertilizers vs Compost
While chemical fertilizers have nutrients in quantity, they typically lack nutrients in quality. This can cause stress for the pineapple plants as they’re unable to absorb sufficient nutrients. Additionally, much of the nutrients from chemical fertilizers are often leached through the soil when watering.
Chemical fertilizers can also have other, unintended consequences, such as killing beneficial soil life and drying out the soil.
Fortunately, compost and manure have been found to contain more than sufficient nutrients for plants (including pineapple plants).
Approximately 70-80% of nitrogen (N), 60-85% of phosphorus (P), and 80-90% of potassium (K) found in feeds is excreted in the manure. These nutrients can replace fertilizer needed for pasture or crop growth, eliminating the need to purchase fertilizers.University of Massachusetts Amherst
Compost also feeds beneficial soil life such as earthworms and mycorrhizal fungi, leading to benefits such as improved soil aeration, nutrient availability, and disease resistance.
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
However, if you’re not big on compost, you can find out more about the fertilizers that I do recommend on my recommended fertilizer page.
Keep in mind that nutrients aren’t everything—pineapple plants also need a specific soil pH to properly absorb nutrients and thrive.
Pineapple plants prefer a soil pH of 4.5 to 5.6 (source).
This is important because an acidic soil pH dissolves the solid nutrients in the soil, and makes them available to be absorbed by 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, SUNY College of Environmental Science and Forestry
Two good ways to check the soil’s pH are with pH strips or a pH meter. I prefer using a meter since they’re affordable and easy to use. To see which pH meter I use and recommend, view my recommended tools page.