Have you ever seen a blue tomato? They are real, and they are a stunning addition to any garden. Blue tomatoes are rare heirloom garden gems that offer a unique color and a rich, complex flavor you won’t find in a supermarket. This article will guide you through everything you need to know to grow these special plants successfully.
These tomatoes aren’t a modern gimmick. They are the result of careful crossbreeding, often involving wild tomato species from South America. The deep blue or purple shoulders come from natural anthocyanins, the same antioxidants found in blueberries. Let’s look at how you can bring these beautiful fruits to your own backyard.
Blue Tomatoes – Rare Heirloom Garden Gems
What makes a tomato blue? The secret is in the skin. The flesh inside is usually a deep red or burgundy, but the skin contains high levels of anthocyanins. These pigments, activated by sunlight, create that stunning indigo, navy, or violet blush on the part of the fruit that faces the sun. They are true heirlooms, meaning their seeds have been saved and passed down for generations.
Popular Blue Tomato Varieties to Try
Not all blue tomatoes are the same. Each variety has its own unique balance of color, flavor, and size. Here are some of the most sought-after types:
- Blue Beauty: A medium-large, beefsteak type with a full blue skin over red flesh. It is known for its excellent, balanced flavor.
- Indigo Rose: One of the first widely available blue varieties. It produces clusters of small, round fruits that are nearly black when ripe.
- Blue Gold Berries: A cherry tomato with golden-yellow flesh and a striking blue exterior. The sweet-tart taste is exceptional.
- Purple Bumble Bee: A stunning cherry tomato with purple and green stripes overlayed on a blue base. It’s very productive and sweet.
- Blue Berries: Another cherry type, similar to its golden cousin but with red flesh inside. It’s a prolific producer.
Why Grow Blue Tomatoes?
Beyond their incredible looks, blue tomatoes offer real benefits. The anthocyanins that provide the color are powerful antioxidants. Many gardeners report a richer, smokier, and less acidic flavor compared to standard red tomatoes. By growing heirlooms, you are also helping to preserve genetic diversity in our food supply. It’s a rewarding experience to save seeds from your best fruits each year.
How to Start Blue Tomatoes from Seed
Since they are rare, you’ll likely need to start blue tomatoes from seed. Order seeds from a reputable heirloom supplier. Start your seeds indoors 6-8 weeks before your last expected spring frost. Here is a simple step-by-step process:
- Fill seed trays or small pots with a sterile, seed-starting mix. Moisten the mix thoroughly.
- Plant seeds about 1/4 inch deep. Gently cover them with soil.
- Place the trays in a warm location (70-80°F). A heat mat can really help with germination.
- Keep the soil consistently moist but not soggy. A spray bottle is good for this.
- Once seedlings emerge, move them to a bright, sunny window or under grow lights for 12-16 hours a day.
- When they develop their first set of true leaves, transplant them into larger pots.
Hardening Off Your Seedlings
This is a crucial step that’s often rushed. About a week before you plan to plant them outside, begin hardening off your seedlings. This means gradually introducing them to outdoor conditions. Set them in a sheltered, shady spot for a few hours the first day, then gradually increase their time outside and exposure to sun over 5-7 days. This prevents shock and sunscald.
Planting and Caring for Your Blue Tomato Plants
Blue tomatoes need the same core growing conditions as other tomatoes, with a couple extra considerations to maximize their color.
- Sunlight: Plant them in the sunniest spot you have. Full, direct sun (at least 8 hours) is essential for developing the deepest blue pigment.
- Soil: They prefer well-draining soil rich in organic matter. Work some compost into the planting hole.
- Planting: Bury the stems deep! Tomato stems can grow roots, so plant them deeper than they were in the pot. This builds a stronger root system.
- Spacing: Give plants plenty of room for air circulation, usually 24-36 inches apart.
- Watering: Water deeply and consistently at the base of the plant. Avoid wetting the leaves to prevent disease. Inconsistent watering can lead to problems like blossom end rot.
- Support: Most blue tomato varieties are indeterminate (they keep growing). Use strong cages, stakes, or trellises to support them early on.
Fertilizing for Best Results
Tomatoes are heavy feeders. Use a balanced organic fertilizer at planting. When flowers first appear, switch to a fertilizer lower in nitrogen and higher in phosphorus and potassium to encourage fruit set. Too much nitrogen will give you a huge, leafy plant with little fruit.
Common Pests and Problems
Blue tomatoes are susceptible to the same issues as other tomatoes. Watch out for hornworms, aphids, and whiteflies. Fungal diseases like early blight and septoria leaf spot can be a problem in humid areas. The best defense is good gardening practices:
- Rotate your tomato crop each year.
- Water at the soil level, not overhead.
- Mulch around plants to prevent soil from splashing onto leaves.
- Remove any diseased leaves promptly.
Many gardeners find that the anthocyanins in blue tomatoes may offer the plants some increased natural resistance to pests and sunscald, but this isn’t a guarantee.
Harvesting and Storing Your Blue Tomatoes
Knowing when to pick blue tomatoes can be tricky. The blue color develops before the fruit is fully ripe. Don’t pick it just because it’s blue! Wait for the fruit to give slightly to a gentle squeeze. The underside (the part not in direct sun) will change from green to a reddish-burgundy or deep purple. The fruit should also come off the vine with a slight, easy twist.
Store your harvested tomatoes at room temperature, not in the refrigerator, as cold damages flavor and texture. Use them within a few days for the best taste. They are excellent fresh in salads, sliced on sandwiches, or simply eaten whole. Their complex flavor also makes a fantastic, uniquely colored sauce or salsa.
Saving Seeds for Next Year
One of the joys of heirlooms is seed saving. Choose seeds from your healthiest, best-tasting fruit. Here’s how:
- Scoop the seeds and some gel from a fully ripe tomato into a small jar.
- Add a little water and let the mixture ferment at room temperature for 2-4 days. This process breaks down the gel coat and helps prevent disease.
- Once a mold forms on the surface, add more water, swirl, and pour off the floating debris and mold. Good seeds will sink to the bottom.
- Rinse the seeds in a fine strainer and spread them on a paper plate to dry completely for about a week.
- Store the completely dry seeds in a labeled envelope in a cool, dark, dry place.
Frequently Asked Questions (FAQ)
Are blue tomatoes genetically modified?
No. The blue color comes from traditional cross-breeding with wild tomato species that naturally contain anthocyanins. They are not GMOs.
Do blue tomatoes taste different?
Yes, most people describe the flavor as more complex, rich, and less acidic than a standard red tomato. Some varieties have a fruity or smoky note.
Why are my blue tomatoes not turning very blue?
The color development depends heavily on direct sunlight. If your summer is cloudy, or if the fruit is shaded by leaves, the blue pigment will be less intense. Prune some leaves to expose the fruit, but be careful not to overdo it and cause sunscald.
Can I buy blue tomato plants at a nursery?
It’s becoming more common, but they are still rare. Your best bet is to start them from seed or check with local specialty or heirloom plant sales in the spring.
Are the leaves of blue tomato plants different?
Sometimes! Many blue tomato varieties have leaves with a slightly darker hue or even purplish veins, especially on new growth. This is another sign of anthocyanins in the plant.
Growing blue tomatoes is a fun and rewarding project for any gardener looking for something special. With a little extra attention to sunlight and seed starting, you can enjoy these beautiful and tasty fruits all season long. They are sure to be the talk of your garden and your dinner table.