We recently planted multiple strawberry plants in our raised bed and in around our garden and one of them simply will not grow. So, I did some research to figure out what was happening. Here’s what I found.
Strawberry plants commonly won’t grow from improper watering, nutrients, and weather. Other causes are transplant shock as well as pests and diseases such as aphids and powdery mildew. For best results, plant strawberry plants in loamy soil, only water when the soil is dry, and provide slightly acidic fertilizer.
So, while strawberry plants won’t grow new leaves for several reasons, how can we identify what’s causing it, and how can we fix it?
1. Improper Watering
Strawberry plants do best when their soil stays moist but has well drainage. The best way to do this is to only water when the top 2-4 inches of soil is dry. This prevents both under and over-watering.
I check this by pushing my finger into the soil, up to the second knuckle.
However, there are times when we need to do more than watering.
Under-watered strawberry plants are common when the soil is exposed to the hot and drying effects of the sun. In this case, the soil’s moisture dries out quickly which means the strawberry plant’s health declines in a matter of days or hours.
To combat under-watering, only water when the soil is dry and apply 1-2 inches of compost and 2 inches of mulch. Compost and mulch both dramatically retain soil moisture while promoting nutrients and beneficial soil life such as earthworms and mycorrhizal fungi.
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
Reapply compost on top of the strawberry plant’s soil every 1-2 months and mulch every 3-6 months. Some examples of mulches are wood chips, straw, leaves, or pine needles. Keep these amendments at least 3 inches from the plant’s stem as it can introduce mold.
Over-watered strawberry plants are often not caused by too frequent watering but by poorly draining soils. This causes the plant to develop yellow leaves and reduced growth.
If your plant’s soil is sopping wet for more than 24 hours, it’s likely poorly draining. You can also test this by doing a soil percolation test.
To combat over-watering, apply 1 inch of compost on the top of the soil. Compost fixes both under-watering and over-watering as it increases the soil’s water retention while breaking up larger clumps of soil, such as compacted clay.
However, for potted strawberry plants with poor drainage, you’d likely be better repotting them with fresh potting soil.
2. Heat or Frost Stress
Strawberry plants are natively from temperate climates, so they prefer cooler environments such as USDA hardiness zones 4-9. To find your hardiness zone and see if it’s compatible with strawberries, see the USDA hardiness zone map.
However, this is a generalization as some varieties prefer warmer or colder zones.
Climates that are too cold (below zone 4) or those that are hot and dry quickly pose a problem for strawberry plants.
Keep strawberry plants in a cool and mild climate if possible. If the sun is too hot, and the tips of the leaves are curling and browning, provide shade or move potted strawberries indoors. When bringing them indoors, take care to avoid the hot and dry air from the central heat.
As always, make sure your strawberry plants get at least 8 hours of direct sunlight daily (aim for the morning sun as it’s cooler).
For ways to combat curling and browning leaves on strawberry plants, check out my other posts: Why Strawberry Plant Leaves Curl and 6 Ways to Fix Brown Leaves on Strawberry Plants.
Hot Weather
In hot and dry areas such as California, Arizona, Nevada, and parts of Texas, strawberry plants lose moisture from their leaves and soil quickly. Normally, strawberry plants do best in temperatures under 80ºF. Any hotter and they may stop growing.
Much like humans, plants cool themselves by exhaling moisture (called transpiration). Plants also keep themselves cool by sending moisture from their roots to their leaves.
This becomes a problem when the climate is too hot and dry. Essentially, the transpiration and root moisture can’t keep up and cool the plant and its leaves.
So, the hotter and drier the weather, the more energy the plant uses to transpire and survive, and the less energy it has to use to establish its root system and grow. This drain of resources can quickly stunt or kill the plant.
The best practices to help your strawberry plant survive hot and dry weather are to provide it with sufficient water, compost, and mulch. Additionally, give it partial shade from the west (as the afternoon sun is the hottest).
Cold Weather
If temperatures fall below -20ºF to -30ºF (the standard zone 4 minimum temperature), strawberry plants will likely start to die.
For outdoor strawberry plants, you can insulate the plant and its roots by providing it with mulch. You can also use windbreaks such as walls or other plants to reduce the effects of windchill. Greenhouses or high tunnels will also work.
I would suggest not moving potted strawberry plants indoors during the winter as they typically require 200-300 chill hours to fruit properly once spring arrives. Chill hours are the number of hours under 45ºF.
Since indoor temperatures rarely get this low, it’s normally not a good idea to bring them inside.
Another issue with moving a strawberry plant indoors is that the central heat indoors can dry out the plant quickly.
I found out about the effects of central heat the hard way.
We had a surprise snowstorm last year here in Austin, Texas, and I moved my potted Meyer lemon tree inside. However, it quickly started losing its leaves. After moving it into a cooler room, it quickly started growing new leaves (see the photo below).
When it comes to sheltering your potted strawberry plant during temperatures below -30ºF, move it to a basement or another cool, sheltered location. Try to keep the temperature under 45ºF to maintain the plant’s chill hours if possible.
3. Improper Nutrients
I used and recommend Down to Earth’s Organic Acid Mix Fertilizer for strawberry plants (pictured above)
Excess Nutrients
When strawberry plants get too many nutrients, their roots are chemically burned which 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.
It’s more common for strawberry plants to not grow or not produce fruit because of an excess versus a lack of nutrients.
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).
A 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 dying 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.
Let’s take a look at the ideal way to prevent a lack of nutrients for your strawberry plants.
The Best Way To Fertilize Strawberry Plants
If you decide to use a chemical fertilizer, opt for one with a balanced NPK (nitrogen, phosphorus, and potassium), such as a 10-10-10.
Each brand has different percentages, so follow the instructions on the label for the best results.
If you’d like to see which fertilizers I recommend, check out my recommended fertilizer page.
Alternatively, you can use compost.
I recommend applying 1 inch of compost every 1-2 months under the plant’s drip line followed by 2 inches of mulch.
Keep in mind that while nutrients are essential, they aren’t everything.
Imbalanced Soil pH
Strawberry plants prefer a soil pH of 5.3 to 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 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.
4. Transplant Shock
If your strawberry plant was recently planted or repotted, and its leaf growth has slowed or stunted, 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.
In this case, the strawberry plant is stopping its canopy growth to instead regrow its roots.
Avoid transplanting 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
5. Pests
Slugs & Snails
Slugs and snails love to munch on the tender leaves and fruits of strawberry plants, leaving behind holes and ragged edges.
Here’s some quick info on how to tell if your strawberry plant is getting eaten by slugs and snails and how to prevent or remove them.
Signs of Slugs and Snails:
- Irregular holes in leaves and fruits
- Slimy trails (known as slime trails) on or around the plants
Prevention and Treatment:
- Encourage natural predators like birds, frogs, and beetles by creating a diverse garden habitat.
- Use beer traps to catch the pests. Simply fill a shallow container with beer and bury it at soil level. Slugs and snails will be attracted to the beer, fall in, and drown.
- Apply diatomaceous earth or crushed eggshell barrier around the plants. These materials have sharp edges that deter slugs and snails from crossing.
- Plant companion plants such as sage, lavender, and rosemary to help repel them.
Pro-tip: If you have ducks, let them have a go at the slugs and snails (they love them)! Just keep an eye on them to make sure they don’t damage your strawberry plants.
Aphids
These tiny sap-sucking insects can cause serious damage to your strawberry plants by sapping the plant’s nutrients and spreading viruses.
Signs of Aphids:
- Yellow, curling, or misshapen leaves
- Stunted growth
- Black sooty mold on leaves (a result of the aphids’ sticky honeydew excretion)
Prevention and Treatment:
- Introduce beneficial insects such as ladybugs and lacewings, which are natural predators of aphids.
- Spray plants with a homemade solution of water and a few drops of dish soap to help dislodge and kill the aphids. Be sure to rinse the plants with clean water after a few hours to prevent soap buildup. You can also use neem oil.
- Use a strong jet of water to knock aphids off the plant (this is what worked when I removed aphids from my Kaffir lime tree). Repeat as needed
Spider Mites
These minuscule pests can be difficult to spot, but they can cause severe damage to your strawberry plants by sucking the plant’s juices and leaving behind tiny, discolored spots on the leaves.
Signs of Spider Mites:
- Fine webbing on the undersides of leaves
- Tiny yellow, brown, or white spots on leaves
- Overall plant discoloration and decline
Prevention and Treatment:
- Keep plants well-watered and stress-free, as spider mites are attracted to stressed plants.
- Release ladybugs or predatory mites, like Phytoseiulus persimilis, to naturally control the spider mite population.
- Spray plants with a mixture of water and a few drops of dish soap to help dislodge and kill the mites. Remember to rinse the plants with clean water after a few hours. Neem oil also works for spider mites.
6. Diseases
Verticillium Wilt
This fungal disease is caused by the soil-borne fungi Verticillium dahliae and Verticillium albo-atrum. It can lead to strawberry plants wilting, yellowing leaves, and even plant death.
Signs of Verticillium Wilt:
- Yellowing, curling, or wilting leaves, starting from the bottom of the plant
- Stunted plant growth
- Brown discoloration in the plant’s vascular tissue (visible when the stem is cut)
Prevention and Treatment:
- Choose resistant strawberry cultivars, such as ‘Allstar,’ ‘Chandler,’ and ‘Honeoye.’
- Practice good crop rotation, avoiding planting strawberries in the same spot where tomatoes, potatoes, peppers, or eggplants have been grown in the past 3-4 years.
- Remove and destroy infected plants to prevent the spread of the disease.
- Improve soil health by adding compost and other organic matter.
Powdery Mildew
This fungal disease, caused by Podosphaera aphanis, is characterized by a powdery white coating on the leaves, stems, and sometimes fruits of the strawberry plant.
Signs of Powdery Mildew:
- White, powdery coating on leaves, stems, and/or fruits
- Curling, distorted, or stunted leaves
- Poor fruit quality and reduced yields
Prevention and Treatment:
- Provide adequate sunlight and air circulation by proper plant spacing and pruning.
- Water plants in the morning, so the foliage dries quickly, and avoid overhead watering.
- Remove and discard infected plant material to reduce the spread of the disease.
- Apply a sulfur-based fungicide or a homemade solution of 1 tablespoon baking soda, 1 tablespoon horticultural oil, and 1 gallon of water. Spray the plants, making sure to cover all surfaces.
Botrytis Fruit Rot (Gray Mold)
Caused by the fungus Botrytis cinerea, this disease can result in moldy, rotting fruits and can also affect flowers and leaves on strawberry plants.
Signs of Botrytis Fruit Rot:
- Soft, brown spots on fruits, which may become covered in gray, fuzzy mold
- Wilted or brown flowers
- Moldy or discolored leaves
Prevention and Treatment:
- Improve air circulation by spacing plants properly and removing any weeds or unnecessary foliage.
- Water plants at the base, avoiding wetting the leaves and fruits.
- Remove and discard any infected or rotting fruits, flowers, or leaves.
- Use a preventative organic fungicide, such as copper or sulfur-based products, when conditions favor the disease (cool and wet weather).
A Note on Pesticides, Fungicides, and Herbicides
We recently had an issue with caterpillars eating our basil plants and we were about fed up. Every time we’d plant basil, the caterpillars ate it.
Fortunately, we found an organic spray at our local nursery that’s made from fermented rum. The day after spraying, we’d find dead caterpillars on the soil.
If you’d like to find out more about this organic spray, you can find it here on Amazon.
So, what’s my point here?
Even though chemical sprays and fertilizers are an easy way out, like all easy and convenient things, there are usually long-term costs. Namely to the plants, soil, and surrounding beneficial life.
Before using conventional sprays, weigh the pros and cons and consider trying organic or permaculture-based treatments first.
To give you a head start, Stefan Sobkowiak – The Permaculture Orchard has a great video on a safe, homemade, and most importantly—effective fungicide (hint: the secret ingredient is whey).