Save Your Stunted Tomato Plant: 6 Fixable Reasons for Poor Growth

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‘Why is my tomato plant not growing?’

Believe it or not, many gardeners still ask that frustrating question, so you’re not alone. Before you give up on your vegetable garden though, read this article.

I guide you through 6 causes that are likely the culprits behind your tomato plant not growing. I also sprinkled in some expert tips, cheat sheets, and easy solutions to fix your problem.

Ready to break records with your crop yield?

1 – Not Enough Sunlight

You’re already aware that sunlight is vital for all plant production—and the same goes for tomato plants. When you don’t provide them with the right amount of sunlight needed for optimal growth, their stems become leggy and their foliage sparse.

Additionally, did you know that your tomato plant’s sunlight requirements will differ according to what growth stage it’s in? For instance, in the early vegetative stage, tomato plants need the most sunlight.

Later on, when the plant is flowering, it’ll need lighter energy to bloom. During this stage, 6-8 hours of indirect sunlight is optimal – just watch out for excess heat and scorching temperatures (>90℉).

Solution: Track Sunlight Intake

Moving your plant to a sunnier location is the first thing to do. Find the right balance between sunlight intensity and duration and your plant’s growth needs.

Here’s a cheat sheet for you:

• Vegetative stage (first 30-45 days after planting): 6 hrs of morning and mid-morning direct sunlight. The plant should face the east.
• Early fruit stage (last 70-100 days): 6-8 hrs of morning and afternoon soon. Avoid direct sunlight and protect the plant on excessively hot days.
• Ripening stage (30 days): 6-8 hrs of indirect sunlight. Hot temperatures (85-90℉) can scorch the plant and reduce pigmentation.

2 – Wrong Soil Type

The soil is the home in which your tomato plant grows. It’s also where it gets its nutrients and food—and when the soil isn’t the right type or pH level, it’ll effectively stunt your plant’s growth.

Keep in mind that the wrong soil type can do more than just that as well.

For example, if the soil is too compact or dense, it’ll suffocate the plant’s roots, leading to root rot. In that case, your tomato plant will stop growing altogether and eventually die.

Solution: Provide the Proper Soil

Choosing the right soil will do wonders for your tomato plant. There’s a simple checklist you should go through before committing to a specific soil type, and that is:

• The soil must be both well-draining and moisture-retentive. Tomatoes are a remarkably thirsty plant, but their roots dislike sitting in water.
• Go for loose soil. Organic, clay, and even regular potting soil are valid choices.
• Soil pH should be between 6.0 and 7.0. pH helps the plant absorb nutrients from the soil so stick to the recommended range.

Expert tip: Add compost when necessary. You can enrich the soil with organic compost or peat moss. Make sure to conduct a soil test beforehand to know which nutrients your tomatoes need more of.

3 – Lack of Proper Nutrients

In addition to soil, tomatoes need a special mix of certain nutrients to grow. Without these essential nutrients, not only is the plant’s growth stunted, but its leaves start yellowing and browning.

Further, a lack of proper nutrients hinders your tomato plant’s ability to produce fruit. Luckily, tomatoes are sensitive and will tell you immediately what nutrient they’re lacking.

Let’s look at a few examples:

• Phosphorus deficiency: Leaves will fall off and fruit production will be slow or late
• Nitrogen deficiency: Spindly growth and yellowing leaves
• Magnesium deficiency: Leave discoloration (also known as interveinal chlorosis)
• Potassium deficiency: Scorching, browning leaves, and no flowering
• Calcium deficiency: Signs of ‘blossom-end rot’ are evident, including young leaves curling

Solution: Enrich Soil With Necessary Nutrients

Once you pinpoint what nutrient your soil is lacking, correcting the deficiency becomes a piece of cake. Simply add the corresponding fertilizer to the soil and watch your plant thank you.

Expert tip: Don’t overdo it. Even though these nutrients are essential for tomato plants, measure quantities beforehand.

Too much nitrogen, for instance, can increase leaf production but stunt flowering growth.

4 – High Temperatures

Tomatoes may love the sunlight, but they despise the heat.

High temperatures can wreak havoc on your plant and cause tremendous heat stress. This condition manifests itself in stunted growth, leaf discoloration, unripe tomatoes, and no more fruit production.

Tomato plants won’t grow if the temperatures are too cold either (>50℉).

That’s why there’s an ideal window to plant tomatoes (from late spring to early summer). Any later, and you risk frostbite, catfacing, and chilling injuries—especially if the plant is still young.

Solution: Regularly Monitor the Area’s Weather

Consider the climate you live in and its weather conditions so you know which measures to take during extreme temperatures and heat waves. Here’s what I found can help:

1. Provide shade: Put up shading structures, such as awnings, gazebos, or floating covers, to protect your plant from excess heat.
2. Frequently water your plant: Tomatoes are thirsty by nature, and when it’s hot out, they’ll need the water. As such, increase watering frequency two or threefold.
3. Opt for container gardening: Growing tomatoes in containers allows you more freedom to move the plant as necessary and avoid the heat.
4. Harvest ripe fruit early: Harvesting ripe and nearly-ripe fruit early reduces the stress the plant goes through to survive the heat.

Remember: Maintaining proper temperatures stops your tomato plant from going into survival mode.

5 – Infrequent Fertilization

You know they’re thirsty plants, but did you know that tomatoes are also heavy feeders?

Infrequent fertilization will affect both the plant’s growth and ability to produce fruit come harvesting season. Even more, tomatoes kept in containers need to be fertilized more often than those planted in soil.

That’s because, in containers, roots can only go so far. They won’t be able to dig into deeper layers of soil to get the nutrients they seek.

Solution: Keep Track of Fertilization Frequency

Here’s what I do: Set a date in my calendar to remind me to fertilize my tomatoes. Since it’s a monthly occurrence, it makes it easier for me to remember if it’s a set date.

So, every 4-6 weeks, make sure to apply phosphorus-rich fertilizer to your plant. You can also mix in a liquid variety to the water, and use that to water your tomatoes.

6 – Overwatering

The telltale sign of overwatering lies in yellow, wilting leaves. If you touch your tomato plant’s leaves and they feel groggy or blistered, you’ve overwatered the soil.

You don’t want the leaves to feel dry or crispy either since that’s a symptom of underwatering. Instead, the leaves should be a healthy green (so should the stem) and have a soft fuzz to them.

The finger test comes in handy, too. Dig about a fingertip into the soil to check if it’s waterlogged.

If the soil is simply moist, you have nothing to worry about! In case it’s too wet (even when it’s hot out), you need to do some damage control.

Solution: Improve Drainage

Lucky for you, your tomato plant can bounce back from overwatering in a week or two – provided you follow my advice below, of course:

1. Dry out the soil: Sounds instinctive enough, and that’s why it works. Stop watering your plant till the soil dries up and then resume watering.
2. Cut off mushy roots: In cases of extreme water lodging (root rot), you’ll need to remove the plant from the ground/container and cut off mushy or discolored roots. Replant in new, better-draining soil.
3. Add sand or perlite to the soil: For a quick fix, add sand or perlite to your soil mix to improve drainage.

Final Thoughts

With that, I’ve given you every possible reason your tomato plant isn’t growing. My post should’ve helped you determine who the culprit is and how you can easily fix it.

Make sure you hit the basics first: adequate sunlight, correct soil type, sufficient nutrients, and ideal watering frequency.

If you’re still facing trouble, dig deeper. Maybe the temperatures aren’t right or you’re not feeding your plant enough fertilizer.

That’s it from me; happy gardening!

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