Red Leaves on Your Strawberry Plant? Here’s Why!
If the leaves on your strawberry plant have started to turn red, you may be wondering why it happens and if there's any reason to be concerned. In this article, gardening expert and former organic farmer Logan Hailey walks through why your strawberry plant's leaves may be turning red, and how to address it.
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Strawberries are one of the easiest and most gratifying fruits to grow in your garden. With day neutral varieties, you can plant them in the spring and start eating delicious fresh berries by mid-summer.
The contrast of vibrant red berries against the backdrop of lush foliage is as beautiful as it is delicious. But when strawberry leaves start losing their signature deep green color, it could sign of a deeper issues.
So, if you are puzzled by the red leaves of your strawberry plant, you’ve landed in the right place. Here’s everything you need to know about why your strawberry leaves are turning red, plus how to fix it!
The Short Answer
Strawberry leaves may begin to turn red after a cold snap when they aren’t getting enough nutrients, or because of plant disease. Red strawberry foliage is a sign that individual leaves are dying. While red leaves can result in lower fruit yields, they can also be remedied by making changes to the growing environment. Sometimes, red leaves are just a part of the plant’s seasonal cycle before moving into winter dormancy.
The Long Answer
Red, maroon, or purple strawberry leaves are undeniably alarming to see in your garden. While autumn often ushers in changing leaf colors in preparation for plant dormancy, red leaves earlier in the growing season can indicate an issue that needs to be remedied ASAP.
We recommend carefully monitoring your plants and using a process of elimination to identify the root cause.
Cold Temperatures
Maroon leaves in the late fall and winter are fairly normal for strawberries. Strawberries are hardy in zones 2-11, but they drop their leaves before going into dormancy. However, premature cold temperatures (especially a late spring frost) can often “trick” the plants and cause a change in pigment.
Young plants are most susceptible. Cool spring weather and transplant shock for recently transplanted strawberries could lead to reddening leaves in new plantings. On the flip side, mature plants may naturally drop their oldest lower leaves in preparation for new growth.
However, this type of reddening will typically affect only old lower leaves or the whole plant in the early winter. If the weather has been consistently warm and/or the red pigment is confined to splotches or margins, you’re probably dealing with another issue.
If more cold weather is coming (early in the season), protect your plants with row cover. I always prefer to cover newly planted crowns for added warmth in the spring. If it is the fall, let them go through their natural cycles. To prevent strawberry disease issues, remove leaves once they’ve fully shriveled and turned brown.
Leaf Scorch
If the redness on your strawberry leaves appears as speckles, dots, or splotches, leaf scorch is probably the culprit. The fungus Diplocarpon earlianum causes red and purple lesions on the leaves.
These can gradually spread to entire leaves, petioles (stems of leaves), fruit stems, and the sepals (top leaves on the fruits).
Unlike the even leaf reddening caused by cold weather, leaf scorch creates a characteristic “burnt” look. This diseas is most common in the early spring or late fall when the weather is wetter and cooler. The symptoms of leaf scorch include:
- Initialy purplish-brown speckles and dots like “tar drops”.
- No defined border around the spots (the leaf spot disease causes a margin).
- Patches fuse into bright red or purple lesions that look sick and infected.
- Irregular blotchy pattern of brown, red, and purple.
- Leaves dry up, turn brown, and curl at the edges.
- Leaves look scorched like they’ve been burned by fire.
Fortunately, leaf scorch can look bad but doesn’t always affect fruit yields except in cases of extreme infection. During extra rainy seasons, monitor your plants for leaf scorch so you can catch symptoms early on. Prevent the spread by removing infected leaves and debris. Apply a neem spray preventatively every 1-2 weeks.
If you live in a humid area that is prone to fungal infections, choose leaf scorch-resistant varieties like ‘Hood’, ‘Rainier’, or ‘Seascape’. Be sure to increase spacing and airflow between plants.
Leaf Spot
Leaf spot is extremely common in perennial strawberry plantings. It typically shows up during extended wet periods of late spring. It is caused by the fungus Mycospharella fragarieae, which has spores that blow in with the wind or spread via overwintered dead foliage.
Leaf Spot Symptoms
- Rounded small, dead spots look like speckles on leaves.
- ⅛ to ¼ inch spots turn purplish to deep red.
- As the disease progresses, the lesion centers turn tan or white.
- Spots may merge into blotches and kill whole leaves.
- Shallow black spots (up to ¼ inch) on fruits.
- Black or brown leathery texture on fruits near spots.
Technically, there aren’t any cures to this strawberry disease. However, scientists say it is typically an aesthetic issue that won’t cause major issues unless your plants start losing tons of leaves. The best thing you can do is keep your strawberry planting very clean by removing debris and never letting dead leaves overwinter in the garden.
Mow dead plants in the fall after they finish fruiting to encourage new growth. Avoid overhead irrigation. You can also grow day-neutral strawberries as annuals that you can rotate around your garden. Resistant varieties include ‘Ogallala’, ‘Ozark Beauty’, and ‘Earliglow’.
Wrong Soil pH
Strawberries are known for their love of slightly acidic soil. These little red berries are actually native to North American forests where they thrive in the pine needle duff of coniferous forests. But when the soil is too acidic or too alkaline, strawberries can begin to show signs that they are unhappy (often in the form of red leaves).
Recall that soils in cold, wet climates tend to be more acidic. You can find acidic soils in the Eastern, Southeastern, and Pacific Northwestern parts of the U.S.
Alkaline soils are common in hot, dry regions like the arid West, Southwest, and Rocky Mountains. Alkaline soil tends to cause more issues for strawberries due to nutrient unavailability (described below).
Just remember that these are broad generalizations and there are huge variations in the parent rock, texture, organic matter, and climatic variations of soils throughout the country. Soil tests are necessary to determine what’s going on in your garden specifically.
To fix this problem, you first need to have your soil tested for the pH values. You can go with a lab or at-home soil test.
Once you’ve determined your soil pH, amend your strawberry beds as needed:
- If you have acidic soil, use these to make the soil more alkaline (raise the pH): Limestone, dolomite lime, wood ash, bone meal, ground eggshells, or oystershell.
- If you have alkaline soil, use these to make the soil more acidic (lower the pH): Add sulfur, peat moss, cottonseed meal, or mulch with pine needles and straw.
- Finished compost often has a neutral pH and benefits strawberries across the board.
Phosphorus Deficiency
If you’re dealing with a pH issue, you’re probably also facing a phosphorus deficiency. This is because phosphorus is less available to strawberry palnts in ultra acidic soils (pH below 5.5) or overly alkaline soils (pH above 7.0). This reddening is one the easiest to identify because it looks like the edges of the strawberry leaves have been dipped in red paint.
Phosphorus deficiency in strawberries typically causes:
- Leaves begin to turn dark purple, especially at leaf tips.
- Less pronounced leaf veins.
- Older leaves turn red and die prematurely.
- Fruits are small or deformed.
- Delayed ripening of fruit.
- Weak plants with slow growth.
For a quick fix, you’ll first need to bring your soil pH to strawberry’s preferred acidity between 5.5 and 6.9 using the strategies above.
Then, amend with a phosphorus-rich fertilizer such as:
- Manure-based compost
- Blood meal
- Bone meal
- Fish bone meal
- Mineral rock dust
- Rock phosphate
Nitrogen Deficiency
Nitrogen-deficient soils can also cause strawberries to turn red. Nitrogen is a crucial nutrient for supporting healthy strawberry growth and fruiting. These plants require significant fertility to crank out delicious fruits all summer long.
You can differentiate a lack of nitrogen from a phosphorus deficiency by looking for yellowing. Strawberries lacking in nitrogen will have leaves that will appear more yellow before turning red. Instead of being confined to the margins, the discoloration looks like it’s taking over the whole leaf. Unlike a disease, nitrogen defciciency shouldn’t appear spotty or infected.
A weekly dose of diluted fish emulsion throughout the flowering and fruiting period is the best way to ensure your strawberries have ample nutrition to fuel their growth.
Avoid applying excess nitrogen during the spring leaf phase because this can cause the plant to develop more foliage rather than channel its energy toward berry production. Instead, use a slow-release organic fertilizer like high-quality compost or an all-purpose blend at the time of planting.
End of the Growing Season
If red leaves appear in the fall, sometimes it’s just a sign that your strawberries are slowing down for the winter. Just like autumn trees, strawberry plants produce anthocyanins from their accumulated sugars.
There are lots of hypotheses about why this happens, but we do know that these compounds create a red pigment in the leaves as the plant pulls back all the nutrients from those leaves to store in the roots over the winter.
Just let your strawberries run through their natural lifecycle! After the first hard freeze, remove dead debris and add a generous heaping of straw mulch to insulate the crowns through the winter. You should get a fresh flush of green growth in the spring!
Frequently Asked Questions
How do you keep strawberry leaves from turning red?
Maintaining a healthy strawberry patch is the easiest way to ensure that the leaves stay vibrant green and growing. Provide strawberry plants with a rich, well-drained soil that has a slightly acidic pH between 5.5 and 6.9. Fertilize with slow-release organic fertilizers that are rich in nitrogen and phosphorus. Avoid overhead irrigation to prevent disease. In extra wet climates, choose disease-resistant varieties and increase the spacing between plants for more air flow.
Should I cut off red strawberry leaves?
If your red strawberry leaves are caused by a disease, you should remove them ASAP to prevent spread to other plants. Practice proper sanitation of your hands and tools during this process. However, if the leaves are reddening as the plant moves into dormancy, you may want to leave them long enough for the nutrients to be re-allocated from the leaves to the strawberry crown.
Final Thoughts
Ultimately, red strawberry leaves are not usually a big deal. They may look unsightly, but they are unlikely to cause major harm to your yields except in extreme cases. The key differentiators between the common causes of red strawberry leaves are the patterns of discoloration.
A good place to start with your diagnosis is to look at how and when the reddening appears:
- If young strawberry leaves are red after a late spring frost, its probably cold damage.
- If leaves are covered in red or purplish splotches after heavy rains, it’s probably a fungal disease.
- If leaves are turning red around the borders, it may be a phosphorus deficiency.
- If leaves are turning yellow and red at the same time, it may be a nitrogen deficiency.
- If strawberry leaves turn red at the end of the season, it may be part of their life cycle.
When in doubt, nourish your strawberry plants with quality soil, compost, and consistent irrigation delivered to the root zone.
