It’s heart wrenching to see tomato branches curling down. Most gardeners face this issue, but not all can identify the root cause. In this write-up I’ll explain the main causes of curling and how you can fix them.
As a precautionary measure it’s recommended that you regularly check your tomato plants and to have patience after fixing the issue.
Curling of tomato branches (stems) and leaves downwards can be due to environmental stress, overwatering, underwatering or lack of nutrients. Apart from this, fungal infection and diseases can cause this disorder.
You grow from seeds or through seedlings, it’s important that you initially know about the essential tomato plant requirements. For instance, tomato plants thrive in between 55 F to 85 F temperatures. Similarly, this plant doesn’t tolerate frost and soil temperature must be above 50F at night.
Well-drained, nutrients rich soil and 6 to 8 hours of bright sunlight are essential for growing successful tomato plant.
With this basic knowledge of plant requirement you can minimize the issues or disorders associated with them.
Why Tomato Branches Curling Down?
As mentioned above, various factors can result in curling of tomato plant branches and leaves.
#1 Environmental Stress (too dry, too windy or too hot)
It’s not detriment to tomato plant.
Upward curling of tomato leaf and branches is common and you don’t have to worry about.
It is actually caused due to the response from environmental condition. Too dry, too hot and too windy conditions stimulate to change the shape of the leaf.
To combat with the environmental change, tomato plant curls to reduce the amount of surface area exposure towards the wind.
Lack of water or underwatering isn’t the reason in this case, your tomato plant actually not being able to uptake the water as fast as it’s losing the water to atmosphere.
It is nothing but a water conservation trick.
Like too dryness, strong winds and hot sun can cause tomato plants branches and leaves to curl.
Leaf curl to reduce the surface area getting exposed to hot sun, this is a technique to save from the risk of dying.
How to fix:
Its normal condition and you don’t have to worry about it.
However, you can shift the location of the plant if you think the plant is getting exposed to hot sun for long hours.
Apart from this, also make sure this vegetable plant gets enough moisture.
To protect your tomato plants from string winds, you can shift the tomato plant container beside a wall. Else, you can use stakes to allow the tomato plant to grow straight.
Cages, ropes, trellises and greenhouse can save your plant from string winds.
Also Read: When Is it Too Late to Plant Potatoes?
#2 Watering Tomato Plant (Overwatering or Underwatering)
How often you water your tomato plants have great impact on its growth.
Unlike houseplants, edible plants like tomato need more moisture. You must water the plant regularly, but don’t overwater them.
When you fail to moisturize tomato plant with sufficient water, then root unable to transfer nutrients from the soil and produce energy through photosynthesis. This results in curling of leaves and branches.
Watering generously will help to fix the issue.
But, overwatering is much more serious than underwatering.
Out of curiosity most new gardeners moisturize the plant with excess water resulting in root rot.
Yellowing, curling, drooping of leaves are signs of overwatering.
To fix overwatering, you must stop watering the plant and allow the growing medium (soil) to dry completely.
Important: Potting soil plays vital role in watering tomato plant. The soil you choose must be well-drained filled with nutrients.
Before watering, make sure the soil is dry. You can check this by inserting your index finger in the soil; don’t water if it’s sticky and wet. In case if it’s dry, water generously.
Also Read: Watering Basil Plants: How Often
#3 Nutrients Deficiency
Tomato plant is a heavy feeder, to have bounty of harvest you must provide plenty of nutrients through fertilizers.
Lack of nutrients in the soil can results in curling of tomato branches.
Its’ recommended that you test the soil before planting tomato seedling. A balanced NPK ratio will allow the plant to produce good harvest.
High amount of nitrogen in fertilizer will increase the foliage and lower yield.
Add phosphorous to increase the yield.
Nutrient deficiency problem is often associated with container gardening. Lack of micronutrients in the pot, result in curling of leaves.
Molybdenum and boron are two trace minerals whose deficiency will cause leaf curl.
Tomato branch curling due nutrients deficiency is rare because, most soils have essential nutrients. However, due to use of overwork soil and regular watering trace minerals may wash away resulting in plant disorder.
How to Fix:
Use homemade or organic fertilizers 2-3 times in growing season. Also make sure to add compost to the potting soil while planting.
If you’re done checking temperature, sunlight and watering requirements, add azomite fertilizer to your plant. It consists of 70 trace minerals that can help your tomato plant.
#4 Virus & Diseases
Through whiteflies Tomato Yellow Leaf Curl Virus attacks your tomato plants, which results in upward leaf curling. This virus will negatively impact your tomato and pepper yield.
Other signs of this virus attack are yellow foliage margins, curling leaves, smaller foliage, stunted plant growth and dropping of flowers.
Note: Curly top virus doesn’t spread to seeds to tomato plants, so you can use it’s seeds for germination.
How to fix:
Remove branches or plants with initial sings of virus attack. Reduce weeds around the tomato plant to stop whiteflies.
Use low concentrated horticultural oil to repel whiteflies.
Next time while planting, choose tomato cultivars that are resistant to Tomato yellow leaf curl.
Broad Mite Damage
Polyphagotarsonemus latus (Broad mites) feed on young leaves and inject toxins resulting in twisting the leaves.
Even tomato plants that are grown in greenhouse aren’t safe. In Texas, broad mites attacked plants in greenhouse.
How to Fix: Horticultural oils and insecticidal soaps can be used to reduce these mites.
You can also use predatory mites to fight broad mites. (Source)
#5 Insects or Pests
Insects like aphids and whiteflies attack tomato plant that results in curling of tomato branches.
You must check the tomato everyday to confirm no insects or moth is feeding on your vegetable plant.
You can get rid of moth and insects by throwing them out of the plant or spray water to remove them off the tomato plant.
#6 Herbicide Drift and Residue
Herbicides are used to eliminate weeds in the crop. Tomato plant crop can be damaged with even low concentration of herbicides.
If you’re not using this weed killer, then most probably you don’t have to worry about it.
However, herbicides left on mulch, hay and manure can damage your tomato plants. So make sure the mulch you use around tomato plant is free from herbicides.
Further, experts say that plant matter collected from fields that are used aminopyralid herbicides shouldn’t be used in vegetable garden. Note that you cannot use this plant matter for composting.
Summary (Bottom Line)
Tomato branch or leaf curling/twisting may be caused due to various reasons. Strong winds, too hot and too dry temperatures can result in curling. However, this environmental stress can be recovered by time.
Broad mites and curl top virus also causes this disorder. You can stop the spread by removing the plant attacked by mites. Curly top virus doesn’t spread to other plants.
Apart from this watering regularly is very essential to get rid of tomato branch curl. When you fail to water on time tomato leaves curl downwards. Check the soil and mark a watering schedule of plants in your garden. Apart from this, weed killer you might use on other plants can damage tomato plants. So, make sure you don’t use aminopyralid herbicide that results in curly tomato leaves.