We recently planted some strawberries, but we noticed their leaves were beginning to drop. While I had an idea of how to fix it, I wanted to do some research to find out more. Here’s what I found.
Strawberry plants drop leaves due to over-watering, nutrient deficiencies, or diseases like leaf scorch or leaf spot. To fix it, only water when the soil is dry, apply compost or a balanced fertilizer, and remove affected leaves while monitoring for disease symptoms. Some leaf drop is normal as the leaves age.
So, while strawberry plants lose their leaves for several reasons, how can we tell which issue is causing it, and how can we fix it? Let’s take a closer look.
Under-Watering
You can tell if your strawberry plant is under-watered if its leaves are drying, curling, browning, or dropping.
Because of all the factors drying out the soil (sun, wind, temperature, soil type, etc.), there’s not one amount of water to use. But there is a guideline that helps you determine when to water, and avoid watering too much or too little.
The best way to water strawberry plants is to only water when the top 2-4 inches of soil is dry. I like to check this by pushing my finger into the soil.
By only watering when the soil is dry, you’re preventing both under and over-watering.
It’s also a good idea to apply compost and mulch on top of the soil, under the plant’s canopy. Compost significantly provides valuable nutrients, amends soil, and greatly retains water.
For example, every 1% increase in the soil’s richness or organic matter leads to an additional 20,000 gallons of water held per acre.
On the other hand, mulch dramatically reduces evaporation, regulates soil temperature, and prevents soil erosion. Since strawberry plants evolved as understory plants in forests, they’re used to plenty of mulch in the form of fallen branches and leaves. As permaculture guru Geoff Lawton says, “A forest grows on a fallen forest.”
For best results, apply 2 inches of compost every 1-2 months and 4-12 inches of mulch every 3-6 months. Keep both materials at least 3 inches from the plant to prevent moisture buildup and mold.
The combination of proper watering, compost, and mulch will help your strawberry plants thrive and prevent under-watering, which can lead to leaf drop.
Over-Watering
Similar to under-watering, the best way to water strawberry plants is to only water when the top 2-4 inches of soil is dry.
While over-watering is possible by watering too frequently, it is most often caused by poor drainage.
But how can we tell if our strawberry plant’s soil is well-draining?
Drainage Test
The best way to tell if your soil is well-draining is by doing a percolation test. To do one, follow these steps:
- Dig a 12-inch by 12-inch hole
- Place a yardstick in it and fill it with water
- Measure the drainage over 1 hour
Good soil drainage is around 2 inches of drainage per hour. Any more and the soil is draining too fast, any less and it’s draining poorly.
Don’t worry if yours is way off—this is a guideline and not a rule. We have some areas with soil drainage of 5 inches per hour and plants still grow well.
If your soil is draining too quickly, increase its richness with compost and mulch. This encourages more organic matter and soil life (which holds more moisture). It also reduces the soil’s water content from evaporating. By increasing the richness of your soil, you’ll balance the moisture levels and prevent over-watering.
If your soil is draining too slowly, you’ll also want to increase its richness. This is because the organic matter in the soil not only retains water but breaks up the larger clumps of soil—allowing for ideal drainage.
In either case, apply 2 inches of compost every 1-2 months.
However, if your soil is draining too slowly, avoid mulching your strawberry plants as it can trap moisture, preventing evaporation. Instead, focus on adding compost and other organic materials to improve soil structure and drainage.
Improper Nutrients
Nutrients are a central part of the growth of strawberry plants, and too few or too many cause problems.
Let’s take a look at each of the three main things that can go wrong with nutrients for strawberry plants.
Lack of Nutrients
| Nutrient Deficiency | Leaf Symptom |
|---|---|
| Nitrogen | Entire leaf is pale or yellow |
| Iron | Dark green veins, rest of the leaf is yellowing |
| Zinc | Yellow blotches |
| Manganese | Broadly pale leaves, foliage color looks mottled or smeared |
If you haven’t fed your strawberry plant in the past several months, there’s a good chance it may be dropping leaves from a lack of nutrients.
Symptoms of a lack of nutrients depend on the deficiency.
For example, strawberry plants commonly get a nitrogen deficiency and get lightly colored or yellow leaves. If it’s bad enough, the leaves will drop off of the plant.
Let’s take a look at the ideal way to prevent a lack of nutrients for your strawberry plants.
Excess Nutrients
When strawberry plants get too many nutrients, their roots are chemically burned, causing the plant stresses the plant and causes a decline in health. Excess nutrients are often caused by fast-release chemical fertilizers as compost isn’t potent enough.
If you believe you’ve over-fertilized your strawberry plant, I suggest removing as much of the fertilizer as possible via leaching.
To leach, heavily water your strawberry plant’s soil to dilute the existing fertilizer and allow it to flow deeper into the soil (and out of reach of the plant’s roots). You may have to do this at least a few times.
Avoid leaching if your soil has poor drainage as the soil can become waterlogged.
In this case, either apply generous amounts of compost and garden soil to dilute the chemical nutrients, or repot the plant with fresh potting soil (for potted strawberry plants).
Imbalanced Soil pH
Strawberry plants prefer a soil pH of 5.3-6.5.
The reason strawberries (and most plants) prefer a slightly acidic soil pH is that it dissolves the nutrient solids in the soil, making them more accessible to 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
When strawberry plants have an imbalanced soil pH, they develop issues such as discolored and dropping leaves. Additionally, their flowers and fruit drop early and the plant is more likely to develop other growth issues.
Two good ways to test your soil’s pH are with pH strips or a meter. I prefer using a pH meter since they’re affordable and easy to use. To see which pH I recommend, check out my recommended tools page.
If you find your strawberry plant’s soil is too alkaline (above 6.5), provide acidic amendments such as peat moss, sand, and coffee grounds.
On the other hand, if your soil is too acidic (under 5.3), provide alkaline amendments such as charcoal, wood ash, and lime.
Transplant Shock
If your strawberry plant was recently planted or repotted, and it hasn’t been growing since, 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 strawberry plants 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 plant’s current topsoil as possible, without damaging the shallow roots
- Grab the base of the plant’s stem and wiggle lightly
- Using your other hand, scoop up and support the rootball
- Lightly place the plant in the new ground (or pot) and fill it in
- Make sure the soil is at the same level on the plant 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
Pests
1. Aphids
Aphids are tiny insects that love to suck the sap out of strawberry plants. When they’re feeding off of the plant, they cause the leaves to curl, yellow, and eventually drop.
If you’ve read Toby Hemenway’s “Gaia’s Garden,” you might remember his explanation of how aphids reproduce rapidly and can easily overwhelm your plants.
Introducing beneficial insects like ladybugs, lacewings, and hoverflies can help keep aphid populations in check.
And a good blast of water can knock them off your plants (this is what worked for my Kaffir lime tree when it had aphids). Neem oil is also a good alternative.
2. Spider Mites
Spider mites can cause strawberry leaves to turn yellow, develop small, pale spots, and eventually fall off. In “The Holistic Orchard” by Michael Phillips, he talks about how spider mites love dry conditions, so keeping your plants well-watered can be a good preventative measure.
As with aphids, encouraging beneficial insects can help manage them.
3. Slugs and Snails
These slimy critters are known to munch on strawberry leaves, leaving holes and ragged edges, which can eventually cause the leaves to drop.
In “The Resilient Gardener” by Carol Deppe, she recommends using beer traps or copper barriers to deter these slimy pests. You can also try hand-picking them during the early morning or evening when they’re most active.
If by chance you have ducks on your property, consider running them around your plants to decrease the slug and snail population.
4. Vine Weevils
Vine weevils are nocturnal insects that can cause severe damage to your strawberry plants. The adults chew on the leaves, causing notches and irregular edges, while the larvae munch on the roots. This double whammy can weaken the plant and cause leaves to drop.
In “Edible Landscaping with a Permaculture Twist” by Michael Judd, he suggests using parasitic nematodes or beneficial insects like rove beetles to help manage vine weevil populations.
Diseases
1. Verticillium Wilt
Verticillium wilt is a soil-borne fungal disease that can lead to wilting, yellowing, and dropping of strawberry leaves. It can also cause stunted growth and, eventually, plant death.
In “Teaming with Microbes” by Jeff Lowenfels and Wayne Lewis, they discuss the importance of healthy soil in preventing and managing this disease.
You can try adding organic matter to your soil, rotating crops, and growing resistant varieties to minimize the risk of verticillium wilt.
2. Leaf Spot and Leaf Blight
Both leaf spot and leaf blight are fungal diseases that cause dark spots on strawberry leaves, which can then turn yellow and drop off.
In “The Permaculture Orchard” by Stefan Sobkowiak, he emphasizes the importance of proper air circulation and sunlight to prevent these diseases. Pruning your plants and removing any infected leaves can help keep these issues under control. You might also consider using organic fungicides like neem oil or copper-based solutions.
3. Powdery Mildew
This is another fungal disease that can cause strawberry leaves to become distorted, turn yellow or brown, and drop. It’s characterized by a powdery white coating on the leaves.
In “Mycelium Running” by Paul Stamets, he talks about the role of beneficial fungi in suppressing harmful fungi like powdery mildew. You can try applying compost tea, ensuring proper air circulation, and using organic fungicides to keep this disease at bay.
4. Phytophthora Crown Rot
This soil-borne disease is caused by the fungus Phytophthora, which can lead to crown rot, wilting, and leaf drop in strawberry plants.
In “The Permaculture Home Garden” by Linda Woodrow, she discusses the significance of good drainage and avoiding overwatering to prevent this disease. It’s also helpful to remove and dispose of any infected plants to limit the spread of the fungus.
Need More Help?
You can always ask us here at Couch to Homestead, but you should know the other resources available to you! Here are the resources we recommend.
- Local Cooperative Extension Services: While we do our best with these articles, sometimes knowledge from a local expert is needed! The USDA partnered with Universities to create these free agriculture extension services. Check out this list to see your local services.
- Permaculture Consultation: Need help with a bigger project? Send us a message.
