‘Black Krim’ tomatoes bring bold heirloom color, flavor, and performance to the slicing tomato. Depending on weather conditions, hefty fruits ripen to deep purple or dusky rose. The unique color, form, and flavor of this “black” tomato make the heirloom noteworthy in the garden.
These beautiful, beefsteak-sized fruits have dark flesh with deep, juicy interiors and a balanced, rich, sweet, and salty flavor. Let’s explore the heirloom traits and growing qualities of ‘Black Krim’ for an exciting twist on the summer slicer.
Overview
The ‘Black Krim’ tomato is an annual vegetable belonging to the Solanaceae family.
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What are ‘Black Krim’Tomatoes?
This is an heirloom tomato variety with large, flavorful, beefsteak-type fruits. Its origin is as interesting as its color and form. ‘Black Krim’ is a selection in Krymsk, Russia, on the Black Sea across from the Crimean Peninsula. Synonyms include ‘Black Crimea.’
The first commercially available “black” tomato, Seed Savers Exchange introduced it in 1990 after receiving seeds initially from Crimea from Lars Olov Rosenstrom of Sweden. A few years later, the popular heirloom black tomato ‘Cherokee Purple’ came into cultivation.
Heirloom varieties span generations because of their flavor, growth, unique fruits, and performance qualities. This variety is notable for hefty, colorful fruits with a rich, slightly salty flavor.
Characteristics
Late-season ‘Black Krim’ tomatoes ripen to dusky rose and chocolate.
This indeterminate tomato grows and produces fruits throughout the season until frost. It fruits reliably and productively, with meaty tomatoes that weigh 10 to 12 ounces each. The long, leafy vines that reach six feet or more.
In cool climates, the large fruits ripen to dusky rose and chocolate with green shoulders. They’ll turn deep purple-black in more sun and heat, but the sweet, salty flavor remains. The round fruits have squatty, flat tops.
‘Black Krim’ fruits late in the season, yielding mature tomatoes 70 to 90 days after transplanting into the garden. With its tall, continually growing vines, it needs a large tomato cage, stake, or trellis for support.
Native Area
They are tender perennials in USDA zones 10 and 11.
Before ‘Black Krim’ grew near Russia and Ukraine, its wild ancestors hailed from faraway Central and South American coasts. Their original growing range is the narrow coastline below the Andes Mountains from Ecuador to Chile.
Tomato cultivation spread regionally through indigenous cultures and then through Spanish colonists returning to Europe with the fruits. A few centuries later, it became significant in culinary uses.
These are tender perennials in regions where they are hardy (USDA zones 10 and 11) and grow as warm-season annuals elsewhere. They belong to the Solanaceae, or nightshade, family, along with peppers, eggplants, and potatoes, among numerous other plants.
Planting
These plants are frost-sensitive and require warm air and soil temperatures for best growth. They grow easily from seed, with seedlings ready to move outdoors a week or two after the last frost and as nighttime temperatures are above 55°F (13°C). Growth takes off with warming summer temperatures.
When deciding where to plant, if possible, opt for a spot where you haven’t grown nightshades in the past year. Nightshades like tomatoes, potatoes, peppers, tomatillos, and eggplants transmit diseases among the group. Crop rotation helps prevent the spread of any lingering fungus or bacteria in the soil.
Plant seedlings two to three feet apart to provide ample air circulation between plants. If growing in rows, space the rows three to four feet apart.
Plant tomato seedlings deep, leaving a third of the stem exposed (or two sets of leaves) with the rest buried. The covered leaf nodes and hairs grow roots to aid plant stability and nutrient uptake. At planting, install the upright support structure like a large tomato cage.
Transplanting
Gradually acclimate tomato plants to outdoor conditions after frost.
Plants started indoors benefit from a hardening-off period before being planted in the garden. A week to 14 days of gradual outdoor exposure allows the tender plants to acclimate to growing conditions.
As frost passes and temperatures warm, place tomato plants outside in a protected area. Gradually moving them to conditions mirroring their new garden location will strengthen the new plants. Start with one hour and increase by an hour each day until your plants have been exposed to an entire day of sunlight. Then, plant them out.
How to Grow
This large tomato grows best with certain cultural needs fulfilled. However, it’s also an adaptable variety that withstands less-than-ideal conditions. ‘Black Krim’ is a productive and reliable fruiter.
Light
These tomatoes thrive with six or more hours of full sun.
The fruits vary in color according to sun and heat intensity. In sunny, warm southern climates, they ripen to dark purple. In cool climates, fruits are dusky rose and burgundy, and shoulders stay green.
Provide a spot with six or more hours of full sun for plants to flourish. Tomatoes grow in partial shade (four to six hours of sun), though plants become leggy and less productive as shade increases.
Morning sun is ideal, and In southern climates with hot summers, plants benefit from protection from direct afternoon rays. The intense midday sun can burn leaves and fruits.
Water
Tomatoes in containers need regular watering as they dry out quickly.
One to two inches of water per week is best. Consistent moisture with regular, deep watering is best; fluctuations in watering lead to problems like blossom end rot. Overly wet soils contribute to fungal diseases.
Check the soil moisture during dry spells or heatwaves to determine increased water needs. If the soil feels dry one to two inches below the surface, it’s time to water.
Watering at the ground level is best and avoids splashing or drenching the leaves, which promotes disease issues. Hand-water at the base of the plant, or use drip irrigation or soaker hoses for consistent, low-pressure volume to direct water to the roots. If overhead irrigation is the best option in your garden, water in the morning so leaves dry throughout the day.
Tomatoes growing in pots, containers, and grow bags need plenty of water for best growth. Containers tend to dry out more quickly in the summer heat; check them regularly to provide even moisture.
Soil
Adding a three- to six-inch layer of compost enriches the soil.
Provide organically rich, loamy soils with good drainage. Slightly acidic soils with a pH between 6.0 and 6.8 are ideal.
Add a generous three- to six-inch layer of compost to the tomato plot for soil enrichment. Compost helps with aeration, moisture retention, drainage, and nutrition throughout the growing season.
Temperature and Humidity
Space plants appropriately to ensure air circulation in high humidity.
‘This late-season producer thrives in the summer heat, yielding either dark or dusky fruits. Ideal growing temperatures are between 60-85°F (16-29°C), ideally between 70 and 80°F (21-27°C), with starting temperatures above 55°F (13°C) and soil temperatures at 60°F (16°C).
Provide air circulation between plants through appropriate spacing in areas with high humidity and rainfall.
Fertilizing
A low-nitrogen, high-phosphorus fertilizer ensures optimal tomato flowering.
Added nutrients are essential for the best vigor, flowering, and fruiting throughout the growing season. To establish plants, use fish emulsion for seedlings and at planting. Continue with seaweed and bone meal during flowering and fruiting. However, an organic tomato-specific fertilizer is just fine, and often better than a homemade mix of fertilizers.
A low-nitrogen fertilizer with an NPK ratio similar to 8-32-16 or 6-24-24 works well. A higher phosphorous (P) rate and a lower nitrogen (N) level are best to ensure fast flowering and quality fruiting. Too much nitrogen leads to leafy foliage but causes a lack of flowers and other plant problems. A medium-high potassium (K) level in fertilizer works well for tomato growth.
Yellowing leaves can indicate a nutrient deficiency, and lack of calcium uptake may be the source.
Maintenance
Pinch off the lower six to ten inches of growth along stems.
In addition to meeting basic cultural requirements, an important step is mulching, which helps with moisture retention, weed suppression, and soil temperature regulation. Clean, weed-free straw, compost, leaf mold, or aged woodchips do the job.
Pruning is unnecessary, but as large, indeterminate plants, they benefit from pinching off low-growing, suckering offshoots to direct nutrients and growth to the upper parts of the plant.
To increase air circulation at the base of plants, some gardeners find it helpful to pinch off the lower six to ten inches of growth along stems. Do this when plants reach two feet tall.
Propagation
Heirloom vegetables are open-pollinated (not hybrids) and come true from seed. Save seeds from season to season for the next planting or to share.
Growing From Seed
Plant seeds ¼” deep in potting medium in a well-draining container.
Start ‘Black Krim’ seeds indoors four to six weeks before your area’s expected last frost date. To grow tomatoes from seed:
- Plant seeds ¼” deep in potting medium in a tray, cell, or small pot with drainage.
- Place seeds in a spot with temperatures between 70°F (21°C) and 90°F (32°C) for germination. Use a heat mat if necessary.
- Keep seeds well-watered. The potting mix should be evenly moist but not saturated.
- Tomato seeds germinate quickly, usually in 5-10 days.
- When sprouts appear, place them in a sunny location like a windowsill or under a grow light.
- Step seedlings up from cell packs to a 4-inch pot when two to three sets of true leaves appear.
- When seedlings reach six inches tall, harden them off to prepare for planting in the garden.
Common Problems
All tomatoes are susceptible to common pests and diseases in the garden, and the best control for these is prevention through maintaining optimal cultural requirements. Consistent watering, air circulation, soil health, and crop rotation are key components of tomato health. Ensure not to overfertilize. Have fun with companion plants like marigolds, catmint, and dill alongside your crop to draw beneficial insects and promote plant health.
Pests
Manage these by scouting early and using organic pest controls.
Sometimes, garden pests enjoy tomatoes as much as we do. The best way to control insects is to scout them early and to prevent them through non-chemical means. Use organic and food-safe pest controls to treat pests if necessary. Follow label instructions to avoid impacting healthy plants, flowers, and pollinators.
Tomato Hornworm
Control hornworms using methods such as handpicking and Neem oil.
Hornworms are ravenous caterpillars that blend in seamlessly with tomato plant vines. They’re easily spotted as they grow big and strip plants of their leaves.
To control hornworms, handpick them off plants and relocate them far from your tomatoes. They feed on any nightshade plant. If you have native wild nightshades in your yard, reserve them for the hornworm, and support the sphinx moth family. They are pollinators, after all.
Neem oil and biological controls of BT (Bacillus thuringiensis), parasitic wasps, and diatomaceous earth are other methods to rid tomato plants of caterpillars. To bring in parasitic wasps, plant yarrow, dill, and fennel nearby.
Aphids
Although aphids are not likely to inflict severe damage, they impede growth and pose a nuisance.
Aphids, the common sap-sucking garden insects we often find in the greenhouse and garden, usually don’t cause significant damage. However, severe infestations cause plant stress and weakness. Signs of stress include curled leaves and stunted growth.
To control aphids, spray plants with a stream of water early in the day to deter and knock the pests off plants. The beneficial insects visiting tomato companion plants prey on aphids and help with control. Ladybugs are attracted to coreopsis, sweet alyssum, and marigolds. A simple horticultural soap or oil like Neem rids plants of infestation if water and ladybugs don’t take care of the problem for you.
Diseases
Common tomato diseases manifest through symptoms like spotted and mutated.
Be prepared for a few standard disease issues, indicated by spotted, mutated, yellowed, or dropped leaves and stunted growth. Tomato diseases spread quickly, some doing minor damage while others cause significant decline.
Leaf Spot
Prevent the spread of leaf spot by removing affected leaves.
Septoria leaf spot is a fungal disease indicated by small brown spots between leaf veins. Leaves become yellow and drop. Septoria leaf spot appears after heavy rains and prolonged moisture and humidity periods. Alternaria leaf spot can also create spots in a bullseye pattern.
Remove any affected leaves to preserve the plant if you see leaf spot. Destroy them, but don’t add them to the compost pile, as spores can spread. Disinfect pruners after clipping.
Wilt
Symptoms of this include yellowing and wilting starting from lower leaves.
Fusarium and verticillium wilts are common fungal diseases. These pathogens affect the plant’s roots and spread quickly among nightshades.
You may notice one side of a plant yellowing and wilting, beginning with the lower leaves, followed by leaves dropping. Cut stems may have brown interior tissues.
Unfortunately, there’s no treatment for affected plants. To prevent wilt from spreading, remove and dispose of the impacted tomatoes. Do not plant susceptible plants in that area for multiple seasons. This is where crop rotation and planting wilt-resistant varieties comes in handy.
Mosaic Virus
Manage mosaic viruses by promptly removing infected plants.
Mosaic viruses, such as tobacco and tomato mosaic viruses, are prone to afflicting nightshades. Leaves bear a mottled mosaic pattern in light and dark greens and may curl and distort.
As with leaf spot and wilt, mosaic viruses do not have a treatment. The best action is to spot them early and remove infected plants. Also, remove any fallen leaves and debris from the impacted tomato to prevent the spread. Again, don’t plant susceptible plants in that area after removal.
Blossom End Rot
Apply low-nitrogen fertilizer to prevent blossom end rot.
Blossom end rot is a physiological disorder that likely results from fluctuations in watering and the plant’s inability to absorb nutrients, including calcium. You’ll know it is blossom end rot when a perfect tomato forms and suddenly becomes brown and rotted at the base.
There’s potential for healthy fruits after blossom end rot. The specific tomato fruits experiencing blossom end rot won’t reverse, so cutting off the damaged tomato is best. However, future tomatoes won’t necessarily be affected, given even moisture, compost-rich soils, and proper soil content.
Frequently Asked Questions
They are best for fresh eating. They have a rich, sweet, and slightly salty flavor. The unique fruits, in deep purple, red, and chocolate tones, add interest to the summer plate. These heirlooms are also good for roasting, canning, sauces, pastes, and freezing.
These indeterminate growers have vines averaging four to five feet long. They grow in pots and containers large enough to accommodate a robust root system and mature growth. Use a 15 to 20-gallon container and a well-draining potting mix amended with compost. At planting, install a large tomato cage or support structure to hold vines as they continue growing. Check pots regularly to ensure consistent soil moisture.
They ripen in late summer. Ripe fruits have a purple-red blush in cool climates and turn dark purple in warm regions. They’ll be tender given a light squeeze. However, as the large fruits ripen on the vine, they may crack or split. To avoid cracking, harvest fruits before they’re fully ripe, when half green and half purple-red in color with a firm feel. Let them fully ripen indoors.
Final Thoughts
This variety’s rich color, flavor, and form bring an interesting twist to the summer harvest. The unusual fruits stand out in the garden, making them a talking point regarding novel appearance and taste.
They are reliable heirloom growers with productive fruit. Call on ‘Black Krim’ to spice up the tomato collection and add rich tones to the summer harvest.
