Minowase Summer Cross daikon went into my Cairns plot this morning. That is a long white radish bred for heat, which is the only reason I’d risk it up here in the tropical zone in May. I sowed direct, two seeds per station, 12cm apart, about 1.5cm deep, then watered in with a proper soak rather than a sprinkle. Daikon sends a taproot straight down, so I never transplant it. Disturb that root and you get a forked, stumpy thing instead of a 40cm spear.
Sixty days to harvest puts me at roughly 10 July. The catch up here is temperature. This variety wants 15 to 20°C to do its best work, and my Cairns plot sits warmer than that for most of the year. I’m betting on the cooler nights of the dry season to carry it through. If it bolts early, that’s the experiment telling me something. Whether daikon is even worth direct sowing in your zone this week is exactly the call the what to plant now calendar makes for you.
I dropped a few lettuce and some cress along the same row. They sit happily next to daikon and I’ll pull them well before the radish needs the space. Strawberries, leeks and spinach all get on with daikon too, so there’s room to stack a bed if you’re tight on space. The climate zone growing guides spell out spacing and timing for each of those, zone by zone.
What to expect over the next eight weeks
I should see germination in 4 to 7 days. First true leaves the week after, if the slugs leave them alone. The roots do most of their swelling in the back half, so the bed will look unremarkable for a month and then suddenly there’s a radish shouldering out of the soil.
If you’re in the tropics or subtropics and want to follow along, now is a fair window to direct sow daikon while the nights are cooling off. Two things worth doing today: thin to one seedling per station once they’re up, because two daikon fighting for the same hole both lose, and keep the water consistent. A dry spell mid-growth splits the root, and a split daikon is a compost daikon. I’m leaning on the cooler nights of the Dayboro dry season to pull this off, and you can check the live station readings before you commit seed up north.
Cool temperate growers down south, hold off. Your soil is heading the wrong way for a heat-bred radish, and a spring sowing will treat you far better.
A 40cm daikon costs a few dollars at the shops if you can even find one that big. Mine cost a pinch of seed and a watering can. I log every harvest against its shelf price so the savings are a real number, not a guess. The only real risk is that I grow more daikon than anyone in this house actually wants to eat.
