Growing Radish

Raphanus sativas : Brassicaceae / the mustard or cabbage family

Jan F M A M J J A S O N Dec
T                      
P P P           P P    

(Best months for growing Radish in USA - Zone 7a regions)

  • T = Plant out (transplant) seedlings
  • P = Sow seed
  • Easy to grow. Sow in garden. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 8°C and 30°C. (Show °F/in)
  • Space plants: 3 - 5 cm apart
  • Harvest in 5-7 weeks.
  • Compatible with (can grow beside): Chervil, cress,lettuce, leeks, spinach, strawberries, tomatoes
  • Avoid growing close to: Hyssop, gherkins

Your comments and tips

12 Dec 20, Vanessa (USA - Zone 10b climate)
My baby sprouts were devoured in my raised bed, despite using bird netting. No bugs visible. What could it be??? So bummed.
14 Dec 20, (USA - Zone 3a climate)
You may have to go out at night to see what eats them. Could be snails or worms etc. If you can buy it, try some veggie netting.
24 Nov 20, Sarah Browne (South Africa - Semi-arid climate)
Someone is eating my radish leaves. Tiny pinprick holes. Any advice?
25 Sep 20, Dennis Naidoo (South Africa - Summer rainfall climate)
Hi I planted bell peppers tomatoes and brinjals They are flowering and some peppers and tomatoes are showing some fruit. What fertlizer can i use to increase fruit Dennis
05 Oct 20, Nick Baxendale (South Africa - Summer rainfall climate)
Hi Dennis, I use borax, dilute one tablespoon in four litres of water and spray plants when they start to flower, worked like a bomb on my brinjal plants, they also like calcium, take egg shells wash them and then crush into jar of water let stand for a couple of days them treat brinjal plants by pouring water into soil. Please don't forget to wash shells first otherwise you will have a hell of a stink, like my first time. Cheers Nick
27 Sep 20, (South Africa - Semi-arid climate)
A general fertiliser will do. If you start with good rich soil then you really don't need to fertilise again.
31 Aug 20, Kishinchand Chellaram (Australia - temperate climate)
HI, I planet white radish , the laves where the green leaves where long and well but the radish was very thin like a stick very thin . so what is the reason? thanks
03 Sep 20, Anonymous (Australia - sub-tropical climate)
I have grown Daiken and White Hailstone radishes the last couple of years and find they have a far bigger leaf top. As mentioned too much nitrogen probably. In the tropics and sub tropics more a autumn winter crop. Too much shade and they will not grow very well. A picket fence (on the north side of the garden) shading my radishes is enough to stop them from producing a crop.
01 Sep 20, Jon Hosford (Australia - cool/mountain climate)
Radishes typically grow a long thin root with healthy leaves before filling out as the plant matures at about 6 weeks. There could be a number of reasons as to why your plants didn't mature: the soil was over rich in nitrogen fertilizer ( radishes prefer a modestly fertilised soil ); you may not have let them mature long enough before harvesting. Keep sowing the seed about 2 weeks apart for a continuous crop. In warm climates it is wise to grow radishes in between shady plants such as sweet corn. They do best in weather that is not too hot ( 20-25 celcius)
11 May 20, Noah (Australia - cool/mountain climate)
I highly recommend radish to beginners as they are fun and easy to grow
Showing 21 - 30 of 144 comments

Your Black Spanish Radishes are a a winter variety - Germination (seed to seedling) happens at temps of 50f - 75f (10c - 24c) and will take 6 to 10 days. --they take anywhere from 30 to 70 days to mature (that is from sprouted seedling to harvest) - you can harvest them when they are about 3" to about 5". Plant anywhere from about two months before the first expected fall frost to 3 weeks before the first expected fall frost. Your best option is to figure out your first expected frost date - count back 8 weeks and call that your "expected planting date" - then check LAST years temperatures at or around your "expected planting date" -- if the temperatures sync up with the germination temperatures (10c - 24c) for Black Spanish Radishes, then it is a good time to plant, if not try and tweak your "expected planting date" so you will have the correct germination temperatures - and enough time for your radishes to grow. The reason your days to harvest has such a wide range is: you can harvest from 3" up to 5" -- additionally, when planting closer to fall/winter the number of hours of sunlight (and the intensity) varies a lot - for example: in my area on August 10th I get 14:36:05 hours of daylight .... and on September 30th I get 11:43:20 hours of daylight -- both are fairly good planting dates with August 10, 2022 having temps of (high/low) 20.4c/ 12.8c AND September 30th having temps highs of 20.4c and lows of 8.7c ==> but September has about 20% less daylight hours and the suns intensity is much weaker -- this means radishes planted in September will take longer to grow and mature than radishes planted in August.

- Celeste Archer

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This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. Gardenate is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
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