15 Common Problems With Strawberry Plants
Are your garden grown strawberries experiencing problems this season? If you've noticed some issues, but aren't sure how to solve them, you've landed in the right place. In this article, organic gardening expert Logan Hailey looks at the most common problems plaguing strawberry plants and how to fix them!
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With their juicy sweet fruits and vigorous growth habit, strawberries are one of the most popular garden crops on the planet. These vibrant herbaceous plants practically grow like weeds in temperate climates.
When you choose day-neutral varieties, they can quickly yield in the first season. And if you nourish them as a perennial plant, you can harvest delicious fruits for years to come.
However, in spite of their ultra-fast growth, strawberries can pose a few problems for beginners. Whether you plant them too deeply, lack pollinators in your garden, or encounter disease problems, strawberry plants are subject to a range of easily preventable problems.
Let’s dig into the most common issues gardeners face with their strawberries and how to fix them!
Problems With Fruits
What’s the point of growing strawberry plants without enjoying the burst of sweet berries on your tongue? While strawberry foliage can make excellent groundcover, problems with the fruit are a sure sign that something isn’t quite right with your plants.
Flowers, But No Fruit
By the time summer comes around in most parts of the country, strawberries have begun blooming their beautiful white flowers.
But as you eagerly await for the delicate blossoms to grow into scrumptious berries, you may notice that the fruit isn’t developing at all. The presence of flowers yet absence of fruit could mean a few things, including the following.
Lack of Pollination
Strawberries require help from their insect allies to transform blossoms into berries. While the flowers are “self-pollinating” (they have both male and female parts in the same flower), they still need something to move around the pollen inside the flower. Wind and rain can help do the trick, but honeybees and bumblebees are the most efficient at fully pollinating plants for maximum fruit set.
The Fix
Does my garden have buzzing activity of bees and pollinators? If not, plant pollinator-attracting flowers like alyssum, phacelia, marigolds, dill, or calendula. You can also import and release bees. Worst case scenario, you can hand-pollinate strawberry flowers by rubbing a paintbrush around in each blossom (but this can take forever!)
Poor Soil or Nutrient Deficiency
When strawberries are grown in heavy, compacted soil or dense clay, they may be too stressed out to properly flower and fruit. Their roots need plenty of drainage and organic matter to get established and sustain berry production through the summer.
The Fix
Did you properly fertilize and prepare the soil? If not, consider loosening around the strawberry plants with a broadfork and feeding them a diluted fish emulsion fertilizer.
Nutrient Deficiency
Strawberries are heavy-feeders that prefer a nice fertile soil. Without enough phosphorus, strawberries may not have the fuel they need to bloom and fruit. However, too much nitrogen can lead to an abundance of lush foliage growth without any energy channeled toward growing fruits.
The Fix
Measure the soil nutrient density and add nutrients through fertilizer, or bone meal depending on the makeup of your soil.
Weather
If a late spring cold snap occurs while the plants are first developing flowers, it can kill the open blossoms which means no fruit. Likewise, super hot weather can lead to reduced berry production. Strawberries prefer mild temperatures between 40° and 85°F during the fruiting stage.
The Fix
Was there a recent extreme weather event? If so, take steps to protect your plants by adding row fabric or simply holding out for the next flush of flowers.
Pests
If you notice lygus bugs, slugs, aphids, or Japanese beetles munching away at your strawberry flowers, it is unlikely that the plant will be able to yield berries.
The Fix
Are there any noticeable pest or disease issues? If so, use scouting, sticky traps, neem oil, or other treatments to eradicate the problem organism. Then, wait for the next flush of flowers. To prevent future issues, plant companion crops to attract beneficial predatory insects.
Strawberry Variety
Before you start panicking that you don’t have any fruit, be sure to check the variety of strawberry that you planted. While day-neutral strawberries fruit in the first year, ever-bearing and June-bearing cultivars typically wait to burst forth with their berries until the second year.
The Fix
If you’ve picked the wrong variety, you’ll likely be starting over from scratch and need to choose the right berries. Or, you may just have to wait a year until you consistently see fruit.
Small Berries
It’s pretty disappointing to put so much work into planting and tending strawberry plants, only to discover that the berries are a measly inch (or smaller) in size.
Small strawberries are a sign that the plant is facing some sort of stress, which impedes fruit production. If you were craving plump juicy strawberries, but your plants are only putting out tiny fruits, it might be due to:
Poor Pollination
Once again, you need those bees to help make your strawberry dreams come true! Strawberries are actually made up of about 200 seeds called achenes. If only half of these achenes are pollinated, the berries can end up half the size.
Even if you have some bees in your garden, there may not be enough to visit every blossom. In fact, scientists have found that each flower needs at least 5-25 bee visits to reach its fullest size potential!
The Fix
First, check your pollinator activity. Import bees or plant some fast-growing flowers. Alternatively, you can try hand-pollinating.
Lack of Pruning
Just like tomatoes and cucumbers, strawberry plants put off lots of side shoots. These “runners” pull energy away from the main plant and result in less energy for berry production.
The Fix
Next, check your pruning. Use sanitized shears or your fingers to snap off the “runners” that are stealing energy away from the center crown. This may lead to bigger berries in as little as a few weeks.
Plant Age
Strawberries that are less than a year old may put out small berries (especially June-bearing and everbearing types). In fact, it’s typically recommended to remove these varieties’ flowers in the first year so they can focus on root production, then burst forth with huge berries next year.
Alternatively, old plants (3+) years may need a refresh to keep growing big fruits. We like to grow strawberries as annuals or biennial plants to keep them vigorous and high-yielding.
The Fix
If your plants are too young, you may just need to be patient. If they are too old, consider refreshing the patch with a big-berry variety.
Strawberry Variety
Some strawberries are just naturally small. For example, alpine strawberries (Fragaria vesca) produce itty bitty berries that are ultra flavorful.
June-bearing strawberries may produce small berries in their first year and ultra large ones in the second year. Check what cultivar you planted and be sure to choose bigger varieties in the future— we love ‘Albion’, ‘Yambu’, and ‘Jewel’.
The Fix
As mentioned prior, a lack of fruit can be caused by picking the wrong variety, but so can smaller fruits. Make sure you’ve picked a variety that matches your expectations.
Deformed Fruit
Garden-grown strawberries should be conically-shaped and uniform on all sides just like the ones you see in the store.
While some berries may have a little funkiness, the overall harvest should look like a regular strawberry. But if you notice that the berries appear flattened, lumpy, wrinkled, or otherwise misshapen, it may be due to:
Lack of Pollination
Are you noticing a pattern here? Deformed fruit is yet another major sign of pollination issues. If there isn’t enough bee or wind activity, all of the achenes (individual seeds) of the berries won’t get pollinated, resulting in some parts of the fruit having swollen red tissue while other parts stay small, green, and deformed.
This is especially common early in the season when the weather is too cold or rainy for bees to get out and about. Partial pollination means awkwardly shaped fruit.
The Fix
The most important way to prevent misshapen strawberry fruits is to ensure that every flower is pollinated evenly and fully. Once again, you’ll need to attract as many pollinators as possible to your strawberry patch! The more the merrier!
The best strawberry companion plant is sweet alyssum. Buy seedlings from the garden store and get those flowers in the ground right away! If you have extra time on your hands, you can also hand-pollinate with a paintbrush as an insurance policy against deformed fruits.
Nutrient Deficiency
Strawberries are pretty hungry for nutrients across the board, but two specific nutrients have been linked to misshapen fruit— boron or calcium! Boron is particularly prone to leaching out of the soil.
These deficiencies can also cause asymmetrical leaves (the three leaflets are usually symmetrical if folded in half lengthwise).
The Fix
If you suspect a nutrient deficiency, foliar spray your strawberry plants with a solution of ½ teaspoon of borax per gallon of water. You can also side-dress a small amount of gypsum or crushed eggshells to help with calcium issues. Eggshells have the bonus of slicing up nasty slugs who may be sliming nearby!
Frost Damage
Late spring frosts are a real bummer because they can cause fruits with blackened centers or deformed shapes.
The Fix
If your area is prone to late spring cold snaps, use row cover and deep straw mulch to insulate your berry plants as they develop flowers. Just remember to uncover them during the day so bees can get to the blossoms and pollinate them.
Holes in Fruit
We aren’t the only ones who crave a succulent bite into a berry! Depending on the shape of the holes, you can determine what is feeding on your strawberries. Holes in the fruit may come from:
Birds
Flocks (especially starlings) can descend on your garden and do a massive amount of damage in a small time. They will snatch whole small fruits and then peck out the insides of larger berries.
The Fix
If your garden is surrounded by a lot of trees that birds inhabit, consider investing in bird netting to protect your berry crop. You can easily affix this to a low tunnel or arched cattle panel above the bed.
Deer
Deer have an endless appetite for strawberries. They can come in from nearby fields and forests and devour whole fruits, leaves, and stems. Deer tend to leave behind a mess of severely damaged strawberry plants and pellets of poop.
The Fix
Repellants are key for animal pests that sneak in from the perimeters. Fencing can help, but deer can always jump over and rabbits can crawl under. The best deterrent I’ve found is porcine blood meal sprinkled around the perimeter of the garden.
Alternatively, you can buy coyote pee from a hunting or feed store. But the best repellant of all is an outdoor cat or dog to patrol your yard (without damaging your crops).
Rabbits
Like deer, rabbits will sneak into the garden. If they do, strawberries will be some of the first plants they go after, so keep that in mind when planning out your garden.
The Fix
The same fix applies here as it does to deer. Fencing your garden space is optimal, but feel free to use the same natural approaches to repel rabbits from your garden. A barn cat is one of the easiest solutions.
Slugs
Slugs tend to feed on ripe fruit and leave rough, ugly holes that get invaded by other beetles. They can also munch ragged holes in the leaves. Slime trails along the berries and base of the crowns are a sure sign that they’re around.
The Fix
The easiest remedy for slugs is diatomaceous earth sprinkled around the base of your strawberries. You can also try a “beer trap” by pouring cheap beer in a plastic container and burying it at ground level.
While mulch is great for strawberries, you may want to move straw or other materials away from the plants during extra moist cover. Wet mulch can be a breeding ground for slugs.
Tarnished Plant Bugs (TPB)
Also called lygus bugs, TPB cause a strange pattern of holes in ripe strawberry fruits that is sometimes called “catfacing” or “button berry”. The center of a berry will be sunken in and brown or greenish. The tiny nymphs hang out in clusters of hundreds on the berries.
The Fix
White sticky traps can help monitor populations and kill small infestations. A strong stream of water can knock off spittlebugs and aphids. Insecticidal soap or neem oil are the best organic options for dealing with larger pest problems on strawberries. Be sure to remove damaged berries and avoid applying directly before harvest. Remove any heavily infested leaves.
Moldy or Mushy Berries
Botrytis is a nasty grayish mold that loves cold weather and high humidity. Berries that turn moldy while still on the plant or shortly after harvest likely have been attacked by this fungus.
The fluffy, velvety, or powdery appearance makes it easy to identify. Fruit can have mushy rotten spots or missing holes. Botrytis is also the culprit for “mummy berries’ ‘, which are moldy cotton-like masses of berries hanging from the plant.
The Fix
Botrytis can be tackled with neem oil fungicides or biocontrol agents like Bacillus subtilis QST 713 (sold under the brand names Serenade or Cease) and Streptomyces lydicus WYEC 1078 (brand name Actinovate AG).
Sanitation practices are the simplest means of prevention, including the removal of infected berries and dead plant debris. Mulch and drip irrigation will help prevent splashing onto the berries that can lead to mold formation.
Problems With Crowns
The crown of the strawberry is the short thickened stem of the plant that grows roots and shoots from its core. Problems with the center of the plant can lead to stunting, disease problems, and reduced fruit yields.
Planting Too Deeply
If you plant strawberries from bare root crowns (rather than seedlings), you will need to pay careful attention to the depth they go in the soil.
Strawberry crowns planted too deeply may lead to rotten crowns or roots. It can also lead to plants not sprouting at all because their growing tip is buried under the soil.
The Fix
Always plant strawberry crowns at precisely mid-level with the soil. The roots should be fully submerged, but an inch or so of the crown and shoots should stick up above the surface. Never mound or deeply bury strawberry crowns beneath dirt or mulch. This can suffocate them and rot the plants.
No Mulch
Strawberries are called straw-berries for a reason: they thrive when mulched with straw! But compost, landscape fabric, and shredded leaf mulch can also do the trick.
Mulch Will Help:
- Keeping berries clean.
- Protecting berries from rotting into the soil.
- Insulating the plants from extreme temperatures.
- Conserving moisture to reduce irrigation needs.
- Avoiding splash-back from rainfall.
- Keep weed pressure down.
Without mulch, your strawberry crowns can be more susceptible to heat or frost damage. However, too much mulch can also suffocate the crown if you aren’t careful.
The Fix
Add a seedless straw (not hay) mulch around the base of your plants about 1-2” thick. Leave a 1” ring of space around the crown and tuck the rest of the mulch under the leaves. You can also mulch the pathways and areas between rows to prevent weed infestations.
Plant Suddenly Collapses
Sudden plant collapse can be caused by a group of diseases called crown rots. This issue is very noticeable because otherwise healthy plants will suddenly collapse and die almost overnight.
There are three main types of strawberry crown rot— Anthracnose crown rot, Red stele root rot, and Macrophomina crown rot. Their symptoms are similar, and will be seen as the following.
Key Symptoms of Crown Rot
- Wilting foliage even when there’s plenty of water.
- Dead, collapsed plants.
- Discolored orange or brown bark.
- Orangish-reddish core of the crown when cut open.
- Drying and death of older leaves.
- Stunted growth.
- Buds, fruits, and roots may get infected with black spots or lesions.
How to Fit It
Once crowns begin rotting, there is little you can do to save individual plants. Crop rotation around your garden is key for future plantings. Some research has shown that rotating with broccoli and brassicas may help reduce the disease. You also want to source certified disease-free transplants or crowns to prevent bringing any pathogens into your yard.
These crown rots are most common in extremely humid environments like the southeast or northeast. Maintaining adequate air flow and planting your crowns at the proper depth are key prevention tactics. If associated with bluish or bluish blotches, Verticillium wilt may also be the culprit.
Problems With Foliage
The state of strawberry leaves is a sure indicator of overall plant health. After all, there can’t be any berries without healthy leaves to photosynthesize and fuel plant growth. When you see these symptoms in strawberry foliage, you’ll want to take quick action to help plants recover.
Red Leaves
Seeing red fruit against a lush backdrop is the hallmark of strawberry growth. But when you start to notice red-tinted leaves, something may be awry. When strawberry leaves start to turn red, it can be caused by:
Cold Snaps: A sudden bout of cold weather can cause leaves to suddenly turn red and die off. While maroon leaves in the fall and winter are fairly normal, unexpected cold snaps can shock the plants and trick them into changing their pigment prematurely.
Nutrient deficiencies: If leaf reddening is concentrated around the margins of the strawberry leaf, there may be a phosphorus deficiency. On the other hand, strawberries with whole yellowing leaves that turn red may have a nitrogen deficiency.
Leaf Diseases: Leaf spot and leaf scorch are fungal diseases that can cause purplish-brown dots and bright red or purple blotches on the leaves. They may look burnt or leathery. As the disease spreads, dark red leaves will wither and die.
Incorrect soil pH: Strawberries are known to enjoy slightly acidic soil, however, if the soil is at the wrong pH, the plants sometimes start to redden their leaves.
The Fix
Mulching and row cover are the easiest ways to prevent red leaves because they buffer strawberries against early or late season cold snaps. You should also ensure there is plenty of fertility in the soil and amend with compost or fish emulsion if needed. If dealing with leaf disease, preventatively apply neem spray or a fungicide to keep the pathogen at bay. You may want to choose resistant varieties like ‘Seascape’, ‘Hood’, or ‘Rainier’ in the future.
When it comes to soil pH, organic amendments can quickly improve the soil pH to make your strawberries happier:
- For acidic soil: make the soil more alkaline (raise the pH) with limestone, dolomite lime, wood ash, bone meal, ground eggshells, or oyster shells.
- For alkaline soil, make the soil more acidic (lower the pH) with sulfur, peat moss, cottonseed meal, or mulch with pine needles and straw.
- Mature compost often has a neutral pH and benefits strawberries across the board.
Drooping Yellow Leaves
Drooped leaves with a yellow tint are never a good sign in any garden plant. In strawberries, this is typically linked to moisture stress due to overwatering. While strawberries enjoy consistent moisture, they don’t want to be sitting in a puddle of water.
The leaves will start to look yellow or pale and the stems will look limp. The symptoms will be evenly spread out across both old and young leaves.
Poorly drained soil can quickly upset strawberry plants because the roots will get suffocated by the lack of airflow. As a result, they can’t properly funnel water up the plant xylem to keep the leaf cells plump and happy. That’s why plants can still look wilted or droopy when an excess of water is pooled up at their base.
The Fix
Cut back on watering. If heavy rains are pounding your strawberry crop, consider loosening the surrounding soil with a broadfork to add more airflow to the root zone. You can also mulch with compost.
If growing strawberries in pots, check that there are plenty of drainage holes and you aren’t overwatering. Wait until the soil is moderately dried out (but not bone-dry) to start watering again. Always check the soil moisture before irrigating. If your finger comes out dry, it’s time to water.
Brown Leaves
Browning leaves are another indicator that your strawberries are under stress. Although a few older dead leaves at the base of the plant are normal, large amounts of browning foliage could be a sign of:
Overwatering: As described above, an excess of moisture can clog up the strawberry’s root zone. Leaves tend to turn from yellow to brown if the waterlogged conditions persist.
Burnt leaves: If a lot of rain occurs before a sunny day, the refraction of light on the strawberry surface can burn the leaves and turn them brown. The same can happen if you overhead irrigate or spray any type of foliar treatment on the leaves too late in the day.
Frost damage: Crunchy brown leaves are another indicator of cold or frost injury. The browning may first affect the margins and cause curling or drooping. This is nothing to worry about if the plant is about to go into winter dormancy. But in the spring, you may need to insulate the crop with row cover or mulch to protect it from unexpected cold.
Foliar disease: As described in the section on red leaves, leaf scorch and leaf spot can lead to browning or dying strawberry foliage.
The Fix
The good news is that brown leaves are easily removed and regrown. Strawberries are quick to regenerate and, as long as the plants aren’t totally defoliated, they can grow back new leaves in no time. Your best bet is to prune back old leaves, fix any irrigation or drainage issues, and give the plants a nice boost of kelp or fish meal to encourage a flush of new growth.
Holes in Leaves
Strawberry leaves typically have a vibrant green color and finely ribbed surface with three evenly-shaped leaflets. But holey or unsightly leaves mean something is trying to eat the plant, which can significantly set back your berry production.
You can usually determine the pest you’re dealing with based on the shapes of the leaf holes.
Common culprits of leaf holes:
- Ragged, sloppy holes near the base of the plant come from slugs.
- Skeletonized leaves (along with flower damage) can be caused by Japanese beetles.
- Skeletonized leaves with big, irregularly shaped holes are a key sign of armyworms.
- Strawberry loopers leave behind rounded small or large holes.
- Shredded leaves can be caused by severe infestation of insects or deer and rabbits.
The Fix
Most strawberry pests can be controlled with organic methods like companion planting, biocontrol (releasing predatory insects), and sprays like neem or insecticidal soap. Use sticky traps and scouting to identify the exact pest you’re dealing with and then research the species to understand its lifecycle.
Remember that pests typically only attack sick or stressed plants, so the most important prevention will always be keeping your strawberries as healthy as possible from the beginning.
Curled or Cupped Leaves
Plant leaves may naturally have a bit of a curl to them in the morning, but leaves should be fully open and spread out during the day to maximize their sun exposure.
If your strawberry leaves appear cupped upwards and deformed– especially during the spring— you may be dealing with cyclamen mites, powdery mildew, or verticillium wilt.
The Fix
Cyclamen mites are tiny seemingly invisible strawberry mites that infest fall-planted or second-year plantings of strawberries. They also can cause fruit to look as if the seeds are standing out from the flesh of the berry. Miticides for biocontrol predatory mites may be necessary to get rid of them.
For verticillium wilt, reference the sudden plant collapse section on root rots. If you suspect powdery mildew, read on below.
Powdery Texture on Strawberry Leaves
Unfortunately, powdery mildew doesn’t just attack your cucumbers and squash. It is out for the strawberries too and can quickly cause a fuzzy, powdery substance to overtake the leaves.
This is most common in midsummer in the east when warmth and humidity occur simultaneously. It may look like your plants have been dusted with white powder, particularly on the underside.
As it advances, fruits may have a powdery surface and leaves may start to curl, twist, or turn brown. This mildew can severely harm photosynthesis and yields, so it’s best to attack as soon as you notice it.
The Fix
Powdery mildew is most easily combated by pruning dead leaves and applying a fungicide (a great organic option is neem oil or potassium bicarbonate). Prune your plants and ensure adequate spacing to keep airflow through the patch.
Use slow-release fertilizer to prevent strawberries from rapidly growing too much foliage which may reduce air circulation in humid conditions. Never overhead irrigate strawberries that are prone to PM.
Overgrown Foliage or Runners
Pruning strawberries is recommended to maintain the vigor and cleanliness of the patch. While some growers opt for “tangled mat row” systems, pruned strawberry plants have higher yields and a nicer aesthetic.
They also lead to fewer disease issues because there is more airflow between the plants.
The Fix
Strawberry pruning should start early in the season and extend throughout the flowering phase. Identify runners (also known as stolons), by their long leafless stems extending from the crown. They will burst out of the side and start growing new buds at the end to establish a new plant.
Cutting these off will ensure that your strawberry plants put their energy toward flowering and fruiting rather than growing new baby plants. Use pruners or your hands to snap off runners at the base.
Final Thoughts
We’ve all heard the saying “build your life on a solid foundation.” Well, the same cliche rings true for your strawberry planting! The easiest way to prevent all of the problems above is to simply give your strawberries the best possible home, to begin with.
Site preparation and planting are key to a successful berry season. Remember to do the following.
Strawberry Site Prep Tips
- Plant strawberries with pollinator-attracting flowers.
- Some options are white alyssum, yarrow, phacelia, dill, borage, nasturtium, or thyme.
- If your soil pH is above 7.0, acidify the soil pH using pine needles or straw mulch.
- Amend with high quality compost to ensure proper drainage.
- Plant strawberry crowns at the proper depth. The roots should be buried
- Plant strawberries at least 12-18” apart and prune off runners to ensure airflow.
- Use drip irrigation or soaker hoses to provide consistent moisture.
- Avoid overhead irrigation.
Ultimately, an easy start to life makes strawberries much more likely to produce an abundance of berries for summer snacks. However, if you forget to do any of these steps, you can easily fix the most common strawberry problems with home remedies and a little TLC.
