Black Opal Tomatoes are early maturing (great for the UK) and produce great yields of black cherry tomatoes. An improved version of the heirloom black cherry tomato, Black Opal is one of the best black tomato varieties on the market. Selected for its improved growth habit, firmer texture and superior flavour, this extremely productive plant produces masses of 1/2 inch round (14-28g) fruits that are perfect eaten fresh from the vine, superior to red tomatoes when grilled, and also great in sauces and pastes. Every gardener should grow at least one black variety.
- Pack size: 10 seeds
- Type: Indeterminate, Cordon
- Time to germination: 7-21 days
- When to sow inside: February - March
- When to sow outside: March - April
- Spacing: 100cm +
- Soil preference: Fertile, well-drained
- Light preference: Full sun
- When to harvest: July - October
How to grow Black Opal Tomatoes from seed
Tomatoes belong to the same family as aubergines and peppers and should be grown much the same way. They require heat, light and well-drained, evenly moist soil and should be grown under glass.
Sow your Black Opal Tomato Seeds shallowly and aim to keep warm - 18 degrees is ideal. After germination, place on a sunny windowsill, or as we recommend, under LED lights, to grow on and develop in 8cm thin-wall pots before planting out in late spring, pot and all.
We start our tomato seeds under lights to ensure a compact, healthy seedling. If your plant does become leggy, it's fine to remove most of the leaves and plant, so just the crown is above the soil surface. The bonus here is an early, supercharged root system, as roots will grow from the buried stem. We plant along the north wall of the greenhouse to avoid shading out smaller specimens. Relatively drought tolerant, tomatoes thrive with even, consistent watering.
The Black Opal is a cordon or indeterminate variety, which means it will continue to grow and fruit throughout the growing season up until the frosts. Due to their tall vining nature, we recommend training up garden twine. It’s a commercial technique, far superior in time/labour, effort, and effectiveness to staking and tying in. Simply secure a length of twine above and let it hang down to your seedling. Wind the main stem around the twine as it grows. If you must stake, drive the stakes in at an angle, well clear of the root zone.
What to feed your tomato plants
Tomato plants enjoy free-draining soil loaded with plenty of organic matter. As they are heavy feeders, add a few handfuls of fish, blood and bone meal with some volcanic rock dust and some kelp powder to give them a rich, balanced and diverse diet for strong organic growth and cropping over the season. This diet will also help the plants to form strong, well-developed immunity.
By preparing the hole/soil with the above organics before planting and applying a side dressing of phosphorus-rich bone meal or wood ash just before fruiting, you feed the whole soil ecosystem, which provides your tomato plants with a much broader diet. Off the shelf bought chemical fertilisers are limited in their scope and kill life in the soil web, trapping the gardener into spending more time and money repeatedly fertilising. If you are worried or breaking the habit is hard, apply a seaweed or comfrey liquid fertilizer instead. Throw some seaweed or comfrey leaves in a water butt or large bucket and let steep.
Keeping pests away
Black Opal Cherry tomatoes are an open-pollinated type, so we encourage you to save your own seeds. By doing so from your best plants, your toms acclimatise to your particular microclimates and disease vectors year on year. Generally, fairly pest and disease resistant, tomatoes should be rotated every couple of years and given plenty of space as they don’t like humidity. It's for this reason that we plant them near to the open greenhouse door, leaving the moisture-loving cues to thrive in the humid back corners.
Tomatoes are susceptible to fungal issues and blight. Plant spaciously, remove the yellowing older leaves and remove side shoots regularly to increase airflow around your plants. The side shoots are the new growth at 45 degrees between the main stem and fan leaf; their removal will also increase yields.
When ordering Black Opal Tomato seeds from Grow Sow Greener, you will receive free marigold seeds. A beautiful plant that adds interest and beauty in its own right while also a great companion for Tomatoes. Plant marigolds close by to deter nematode attack and attract beneficial insects which prey on pests while boosting pollination.