How to Grow Black Tomatoes (A Beginner’s Guide)


Black tomatoes hanging from the vine.

Tomatoes are one of the most consumed vegetables in the world. And no wonder.  They’re delicious and tasty.

People often assume all tomatoes are red. But, in fact, tomatoes come in various colors, including black.

Like other tomatoes, black tomatoes, too, come in different varieties and sizes. You’ll find anything from meaty beefsteaks to small cherry globes. My article on black tomatoes and taste delves into more detail on what you can expect when biting into one of these beauties.

Black tomatoes are often considered heirloom tomatoes. Tastes vary depending on the variety, but all are delicious and can be used in many ways.  

Although they’re called “black”, most black tomatoes aren’t actually black. Rather, they tend to range in color from deep purples/blues to browns and dark reds. The deep colors give the appearance of being black.

Overall, black tomatoes are easy to grow and they’re often prolific producers. Most are indeterminate, meaning they can grow and ripen at different times throughout the season.

So, let’s take a look at how you can grow your own black tomatoes.

Contents

  1. Nutritional Information
  2. Common Black Tomato Varieties
  3. Planting Your Black Tomatoes
  4. Type of Soil
  5. Light Requirements
  6. Watering Your Black Tomatoes
  7. Maintaining Your Black Tomatoes
  8. Harvesting Your Black Tomatoes
  9. Pests That Affect Black Tomatoes
  10. Diseases That Affect Black Tomatoes
  11. Black Tomato Recipes

A Beginner’s Guide to Growing Black Tomatoes

1. Nutritional Information

According to Nutrition Data, one cup of chopped or sliced tomatoes has 32 calories and the following vitamins and minerals;

  • Vitamin A 1499 IU
  • Vitamin C 22.9 mg
  • Vitamin K 14.2 mcg
  • Folate 27.0 mcg
  • Magnesium 19.8 mg
  • Potassium 427 mg

2. Common Black Tomato Varieties

Black Krim – One of the most popular black tomato varieties. Black Krim tomato plants produce large, juicy tomatoes with a sweet, smoky, bold flavor.  They take around 80 days to mature.

Indigo Rose – The first truly purple tomato as it contains anthocyanins, the compound that gives blue-black fruits and vegetables their dark color. These guys are rich in antioxidants and have a clean, slightly acidic, sweet flavor. They’re ready for harvest in about 75 – 80 days.

Black Cherry – As the name suggests, Black Cherry tomatoes are a cherry tomato variety.  They’re very productive and will ripen throughout the season.  Harvest often.  The taste is fruity, rich, and intense. 

Carbon – Carbon tomatoes are prolific producers, and have won best-tasting tomato awards. They’re one of the darkest purple varieties and they’re known for having a high tolerance for drought and heat. The fruit is large and the taste is rich, savory, and smoky. They’ll be ready for harvest in about 85 – 90 days.

Black From Tula – This is a high-yield, beefsteak variety that’s easy to grow.  They have a flattened globe shape and can reach a very large size.  Give them about 85 days to harvest.  Black From Tula has a wonderfully sweet, rich smoky flavor.

The above is just a sampling of the many black tomato varieties. If you’d like to know of other types, then take a look at my post on black tomato varieties.

3. Planting Your Black Tomatoes

Indigo rose black tomato hanging on the vine.
Photo by Jinx McCombs / CC by

You can plant tomatoes from seeds or seedlings. However, black tomatoes are often heirloom tomatoes and seedlings can be difficult to find at your local nursery or garden center. 

If you’re lucky enough to find a seedling for sale, make sure to avoid ones that are tall, leggy, or yellowing. Pick seedlings that are green and upright, and in general, look healthy.

Since seedlings can be harder to come by, you’re better off planning to grow your black tomato from seed. 

Luckily, they’re easy to grow this way. 

Seeds can be sown in the ground. But, black tomato seedlings can take anywhere from 65 to 90 days before they’re ready to harvest. So, depending on your hardiness zone, your growing season may be too short for directly starting your seeds in the garden.

For most temperate climates, you’ll start your seeds indoors first. Then, as the weather warms, you’ll transplant them to the garden. 

In general, start your seeds indoors about 6 to 8 weeks before they’re ready for outside. For most moderate climates, this will be around March – April. 

Plant your seeds in well-draining soil. If possible, use a seed starting mix. 

Seed starting mixes are light, rich in organic matter, and drain well. They’re meant to give sprouted seeds and young roots easy room to grow and spread. You can plant your seeds in individual pots or in seed trays.

Plant your seeds roughly 1/8 to 1/2 inch deep. They’ll need a spot with plenty of light.  If your home doesn’t have a bright enough area, then place them under a grow light. 

Keep the soil moist as the seeds germinate, but not drowning. (put in seed starting link here once done) Once the seedlings appear, you can taper off on the watering. At this point, they’ll need moderate watering. 

Check your seedlings frequently for moistness, especially if they’re in a seed tray or a very small pot. Since there’s less soil to hold water, these containers dry out more quickly.

Once leaves start appearing, you can move your seedling to a bigger pot if need be.

When to Transplant Your Seedling

Tomato seedlings planted in garden bed.

Don’t be in a rush to transplant your seedlings. Tomatoes need warm soil, as cold soil can stress the plant. It’s important you don’t transplant into the ground until the soil warms and stays above 65°F.

Too, any threat of frost should already be passed. Tomato plants, including black tomato plants, are not frost tolerant.

When your plants are ready to go outdoors, harden them off for several days. This means getting them used to the outside before moving them there permanently. Do this by leaving them out during the day, then bringing them in at night, 

When choosing a garden spot, don’t plant your tomatoes in areas where you’ve grown tomatoes in the past 2 years. The same goes for spots where similar plants, such as peppers or potatoes, have grown. 

By keeping your crops rotated you’ll help prevent disease. Diseases and pests can winter in the soil. If you’re planting your tomatoes in the same spot each year, they’ll be more susceptible to those problems. 

You also want to plant your black tomatoes away from any other tomato varieties.  

Most black tomatoes are heirloom tomatoes. As such, they’re open-pollinating plants. These plants are pollinated by nature, such as the wind, insects, etc. 

As open pollinators, your black tomato plants can cross-pollinate with other tomato varieties if they’re planted close to each other. 

This may not affect the current year’s crop, but it can be a problem if you’re planning on saving tomato seeds to plant the following year. Seeds from a cross-pollinated plant may not grow true to form. In other words, you’ll end up with a hybrid tomato and not the variety you were expecting.

Tomatoes in cages.
Photo by The Food Project / CC by

When you’re ready to transplant your seedlings, dig a hole for each plant. The hole should be deep enough so the soil is just below the plant’s lowest leaves. Your black tomatoes will do better if planted a bit deeper than their pot size.

Tomato plants are fairly large, including black tomatoes. Space out your plants roughly 2 – 3 ft apart.

After planting you can apply a starter fertilizer to give your seedlings a boost.

And if you don’t have a garden spot, don’t worry. Tomatoes make great container plants. Just make sure to use a large pot, one that’s at least 16 – 18 inches in diameter and about 24 inches deep. 

I’ve written a guide on container gardening. You’ll find it helpful if you have any questions.

4. Type of Soil

Black tomatoes prefer well-draining, fertile soil. If planting in the ground,  use good, rich garden soil with some compost or aged manure worked in.

I know from experience how beneficial compost can be to growing tomatoes. Every year, I had a slew of tomato plants spontaneously growing in and around our compost pile.

Aged manure and compost may give your plants a boost, but don’t use fresh compost or manure. Fresh materials can harbor disease or pests, or be too strong for your young plants. 

Tomatoes like slightly acidic soil. In general, they prefer a soil pH of 6.2 to 6.8. If your soil’s pH is too high, work in some peat moss or aluminum sulfate.

Use a pH soil tester to find your soil’s pH level.  For other helpful gardening tools, take a look at my recommended tools for the new gardener.

Fun Fact – the more acidic your soil, the redder your black tomato can look. The less acidic the soil, the more blue-purple it will appear. But, don’t make your soil too alkaline just for appearance’s sake. Your tomato plants won’t fare as well.

If you’re planting tomatoes in a container, use good container soil. The soil should have lots of organic matter, yet be well draining. I don’t recommend using gardening soil as this type of soil can be too heavy for a container.

Too, make sure your pot has drainage holes.  For more information on the different types of plant pots, take a look at my article on the subject.

5. Light Requirements

Three tomato plants in a raised bed.

Tomato plants need lots of sun. At a minimum, 6 hours a day, but they’ll do better with 8 hours or more a day.

With many black tomato varieties, the more sun, the deeper the color.

6. Watering Your Black Tomatoes

In general, black tomato plants need 1 – 2 inches of water per week. It’s especially important you water often right after transplanting. This helps establish those roots.

If tomato plants become too dry the fruit can split and crack.

On top of ensuring they get enough water, it’s important you keep the soil evenly moist.  Inconsistent watering can lead to blossom end rot. A condition where a tomato plant isn’t absorbing enough calcium.

This can be especially problematic when growing your tomatoes in a container. 

I experienced this firsthand. 

I was working quite a few hours at the garden center, and I became sloppy with watering my tomatoes. As a result, many ended up with blossom end rot. 

Lastly, if possible, water your tomatoes in the morning and try not to spray water on the leaves.

7. Maintaining Your Black Tomatoes

To maintain your black tomatoes, look to these three areas;

  • Pruning
  • Fertilizing
  • Support 

Pruning

Black tomato varieties need lots of sun to reach their full color potential. To help with that, you can prune your tomato plants.

Start by cutting any “sucker” branches. Sucker branches are secondary or side stems that emerge from where the stem and the main branch of a tomato plant meet.  

There’s some debate as to whether or not sucker branches are worth keeping. 

Garden lore says keeping them will produce more fruit, but removing them will give you larger fruit on the remaining branches.  

Personally, I always removed sucker branches. For me, they weren’t great fruit producers. 

If you’re a new gardener, it may seem daunting to figure out which branches are sucker branches and which are not. But, as you grow more familiar with your tomato plants, the easier they’ll be to spot. And if you’re growing several plants, you can experiment by pruning some and not others. To learn more about sucker branches, take a look at this article by Espoma.

Keep in mind, if you decide to prune your black tomato plants, you’ll want to leave enough leaf coverage to prevent sunscald on your tomatoes.

Fertilizer

Tomatoes are heavy feeders, so it’s not a bad idea to fertilize your tomato plants. 

First, after the soil has warmed, you can mulch around your tomato plants. This not only [provides nutrients, but helps with water retention and keeping weeds down. 

As your plants grow, use a fertilizer with more phosphorus and potassium and only moderate nitrogen. Higher nitrogen levels encourage a lot of green on a plant. So you end up with bigger leaves and stems, but not as much fruit.

You’ll know the different amounts of nutrients by looking at the fertilizer label. Nitrogen is the first number, phosphorus the second, and potassium the third. 

Fertilize around the plant, not directly on top of it, and follow the package directions. 

Supports

Photo by Drew Stefani / CC by

Tomato plants are large, heavy plants. And it’s no different with black tomato plants. Because of this, most gardeners either stake or cage their tomato plant to give it support as it grows.

Either method works. But, whichever you choose, ensure you put the support in place when the plant is young. This way, there’s much less chance of damaging the plant or its roots.

If staking your tomatoes, push the stake down 8 – 10 inches deep. I’ve experimented with putting stakes next to the plant and several inches away.  Both work – as long as you stake the plant when it’s young. 

If you wait until your plant is larger, then aim for staking 6 – 10 inches away from the main stalk. This minimizes the chance of you hitting a root.

Once the stake is in place, you’ll need to tie the plant to it. 

There are many plant tie options.  You can even make your own. But, whichever you pick, make sure the tie is soft and won’t damage the plant’s stem. Personally, I always use vinyl ties. I find them soft, flexible, and easy to use. 

Keep in mind, as the plant grows you’ll need to adjust the placement of the ties.

If staking your plant sounds like too much work, consider using a tomato cage.  

A cage is a great alternative to a stake as it’s less labor intensive. The downside is it’s usually more expensive.

Cages can be round, triangular, or square in shape. I always liked the square ones because you can open them up and use them for multiple purposes. I loved using them as support for my sweet peas.

Just as with stakes, put your cage in when the plant is young. The aim is for the plant to grow inside and through the cage. If you wait too long your tomato plant will become too large for you to fit the cage around it.  This is especially true with round cages.

To learn more about the different types of plant supports, take a look at my article on the subject.  You’ll find it helpful.

Now, there’s no law that requires you to stake or cage your black tomatoes. But, if you’re not providing support, you’ll need to ensure your tomato plant has enough room to sprawl. If leaving to sprawl, increase the space between your plants when planting.

For tomatoes growing in a container, I would recommend staking or caging. Otherwise, your tomato plant may become too top-heavy and if it falls over the side of the pot, the stem can be damaged.

8. Harvesting Your Black Tomatoes

When to harvest your black tomatoes will depend on the variety you’ve planted. In general, watch for a deepening of the tomato’s color. The fruit should be firm but not rock hard.

If you’ve ever eaten a green tomato, then you know what an unripe tomato feels like. 

I’ve written an article on how to tell when black tomatoes ripen.  You’ll find it helpful when it comes to determining if your tomatoes are ready for plucking.

Most black tomato varieties are indeterminate. This means the fruit grows and ripens at different times. This can give you tomatoes throughout the growing season, but you’ll have to keep an eye on them. 

Once picked, you can further ripen your tomato by leaving it in a sunny spot indoors, such as a bright windowsill.

Regardless of which black tomato variety you plant, it won’t be frost-tolerant. So, harvest your tomatoes before the first frost.

Harvesting Seeds for Next Year

Many gardeners like to save tomato seeds for replanting the following year.  As an heirloom tomato, unless it’s been cross-pollinated, your black tomato will grow true from the saved seeds. This means you’ll end up with the exact same tomato next year. 

If you’ve chosen a black tomato variety that’s harder to come by, you’ll definitely want to consider saving the seeds.

When saving seeds, keep the following in mind.

  1. Collect your seeds at the end of the season.
  2. Only collect seeds from healthy plants.
  3. Ensure your seeds are properly dried and stored.

For more information on how to harvest tomato seeds, take a look at this article from The Spruce.

If you’re not into keeping seeds, don’t worry. There’s a good chance you’ll find tomato plants unexpectedly popping up in your garden next season. Especially if you haven’t extensively tilled the ground. If a tomato splits open, the seeds can fall out, stay in the ground and germinate the next year. I know I always had little tomato plants poking up here and there. 

If this ends up being the case, dig up those seedlings and transplant them to this year’s garden spot.

How to Store Your Tomatoes

In general, store tomatoes at room temperature and use them as soon as possible. This is especially true if they’re not yet completely ripe.  

Cool air can break down a tomato’s flavor compounds. So, keeping tomatoes at room temperature will help maintain their best flavor. This is why you don’t see tomatoes refrigerated in the produce section of a grocery store. 

However, once ripe you can put tomatoes in the fridge. Especially if you won’t be using them right away. Keeping it in the fridge will help it last a little longer.  Tip: Once in the fridge, tomatoes should stay in that cooler environment and not be set back out onto the countertop.

Black tomatoes have a shorter shelf life than red tomatoes. It’s one of the reasons you don’t find many black tomatoes in a grocery store. So, use your black tomatoes sooner rather than later.

9. Pests That Affect Black Tomato Plants

Common black tomato pests include;

10. Diseases That Affect Black Tomato Plants

Common black tomato diseases include;

11. Black Tomato Recipes

Black tomatoes are delicious, versatile vegetables. Here are just a few ways to make use of this tasty edible.

Final Thoughts

  • There are many varieties of black tomatoes. Most are heirlooms and indeterminate, meaning they can ripen at different times.
  • Although called “black tomatoes”, most varieties are not truly black, but instead a deep purple, blue, brown, or red.
  • Many gardeners grow black tomatoes from seeds as it can be difficult to find seedlings.
  • In most climates, you’ll start your seedlings indoors, then transplant them to the garden once the threat of frost has passed.
  • Tomatoes need 1 – 2 inches of water per week and at least 6 – 8 hours of sunshine per day.
  • Tomatoes plants need support as they grow, or enough room to spread.  Stakes and tomato cages are the most common type of support.
  • To get abundant, large fruits, fertilize with a fertilizer higher in phosphorous and potassium and lower in nitrogen.
  • Tomatoes are not frost tolerant and must be harvested before the first frost.
  • You can save the seeds for reuse the following year.
  • Black tomatoes do not have as long of a shelf life as other tomatoes. It is better to use them sooner rather than later.

If you enjoyed this article on how to grow black tomatoes and found it helpful, feel free to share it with your friends.

Angela

Hi! My name is Angela Carr. I started this site to share my love for plants and gardening. My aim is to provide my readers with easy tips and tricks on plant care, fun facts, and encouragement for the new plant owner or anyone questioning the colour of their thumb!

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