Growing tomatoes: best varieties to plant
I'd be lying if I said I was on friendly terms with homegrown tomatoes. The last time I grew a cracker crop was 2013, the same year I developed a severe allergy to even the gentlest encounter with their hairy foliage. I'm a strictly gloves-on gardener now.
But rashes and blisters aren't the only reason for my fraught affair with tomatoes. Blight is another perennial bugbear and the wet start to spring can't help. In the past 12 months we've had 2240mm of rain in Hunua, a metre more than the 22-year average.
Every year my tomatoes succumb to blight but that only makes me more determined to find a practical solution. Rather than turning to sprays, I'm trying a new tack and only planting early-ripening bush or determinate varieties. I'm dead keen to see how the apparently crack-resistant cherry variety 'Gardener's Delight' (King Seeds) goes as it was one of the star performers from the Auckland Botanic Gardens' tomato trial last year. Results are summarised in the photo gallery below.
As a rule, if your climate thwarts your tomato crop – if it's too cold in spring or summers are short – seek out varieties with "early" in their name. Try 'Baxter's Early Bush', 'Early Doll', 'Early Girl' (or improved 'New Girl').
Every microclimate has its quirks. "When you grow on the margins," says Catlins gardener Wendy De Boer, "the biggest problem is getting the calves out of my polytunnel so the tomatoes can move in!"
Last summer, the Auckland Botanic Gardens set out to investigate how best to grow tomatoes outdoors without blight, bugs and blossom-end rot ruining your crop. The Botanic Gardens actively avoid using sprays so one of the aims of their trial was to find out how much (if any) chemical intervention is required to get a great crop in Auckland's humid climate.
• For the trial, 152 plants of 13 varieties were sown (in mid-August), grown on, and planted out (at the end of October) in trial beds prepared with 1 cup of biofert/m². The plants were spaced 80cm apart in rows running north to south, in full sun, and exposed to the prevailing wind. The laterals were removed and the plants were tied to supporting trellis.
• Some plants were sprayed weekly with liquid copper, while control plants were not. However, last summer wasn't bad for blight and only one 'Money Maker' plant in the trial was affected, so it was impossible to tell if the copper sprays made any difference.
• Is liquid fertiliser worth it? No. Despite fortnightly applications of seaweed-based liquid fertiliser during the growing season, there was no noticeable difference to either yield or flavour. "An unnecessary expense," the trial team concluded.
• Of the 13 varieties chosen, five were cherry tomatoes, five were medium-sized and three were large meaty types. There wasn't much variation in the weight or size of the cherry varieties, regardless of how they were grown, but 'Sweet 100' and 'Sweet Gold' produced the greatest numbers of tomatoes.
• Of the medium-fruited cultivars, 'Juliet' had a significantly higher number of fruit but because they weighed less on average, the other cultivars produced similar yields. The individual fruit of 'Chef's Choice Orange' and 'Early Money' were larger and heavier.
• Big isn't always best. Of the three large-fruited cultivars, 'Country Taste' was the most prolific. The plants of 'Beef Maestro' weren't particularly vigorous and were first to die back (before the end of the trial), causing their grades to slip! Meanwhile, 'Marriage Big Brandy' didn't always live up to its name, with some plants producing juicy big whoppers while others yielded cherry-sized tiddlers.
• If you're impatient, note that there was a one-month difference between the earliest and latest varieties to ripen. 'Sweet Gold' and 'Gold Nugget' were quick to colour up, while 'Beef Maestro' and 'Marriage Big Brandy' came in last. This isn't unusual, as cherry tomatoes always ripen first. In general, cherry varieties seem to do better than other tomatoes.
• A public taste test of all 13 varieties threw up some surprising results. When asked to rate each tomato for flavour, sweetness, appearance and personal preference, everyone agreed that 'Sweet 100' was the sweetest. But as for flavour, the public's palates showed "variable results with no consistent preference" and opinions didn't align with the Brix testing results.
• 'Sweet 100' had the highest sugar levels for a cherry tomato; 'Juliet' won the medium category; and 'Country Taste' was the sweetest large fruit.
Tips for growing tomatoes in New Zealand
• Don't transplant tomato seedlings until Labour Weekend. The weather is too unsettled until then.
• Tired of tasteless tomatoes? Try "dry farming" (halt all watering once the fruit is forming) or give them a splash of sea water. Research at Rutgers University in the US found that tomatoes given a one-time drench with 1.5 litres of sea water (or 4 teaspoons of salt dissolved in the same volume of water) tasted better and also ripened up to 15 per cent faster.
• F1 hybrids are the work of plant breeders. They are the first generation raised by cross-pollinating two different types of tomato. You can save your own seed from F1 fruit but when they grow the following season they won't necessarily turn out the same (be "true to type"). But open-pollinated tomatoes, such as heirloom varieties, are more stable and will look like their parents.
• Indeterminate varieties grow as tall vines. They keep growing and produce fruit until the first autumn frosts kill the plants off, whereas determinate or bush types are more compact with a strong central leader. They don't need as much staking but fruit for a shorter season.
Tips for growing tomatoes in containers
• If you want to grow tomatoes in pots, choose varieties bred for this purpose. Stick to cherry tomatoes, tumbling tomatoes and determinate or bush tomatoes. Most are quick to crop within 120 days from seed.
• Take your pick from 'Tumbling Tom Red' (Egmont Seeds, pictured) or its cousin 'Tumbling Tom Yellow'; 'Tiny Tim' (Yates); 'Balcony' (Egmont Seeds), 'Container Choice Red F1' (Kings Seeds) or 'Patio F1' (Egmont Seeds).
• Aim for non-permeable pots at least as big as a 10-litre plastic bucket (for a single plant) or cut holes in a 40-litre bag of potting mix and slip seedlings straight into it.
• The main challenge is always watering. Tomatoes in hanging baskets need a good soak twice a day; an automatic irrigation dripper is best. Never water the foliage. Use a potting mix that includes a wetting agent.
Read more about growing veges in pots and small spaces.
- NZ Gardener