Growing Radish

Raphanus sativas : Brassicaceae / the mustard or cabbage family

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

(Best months for growing Radish in USA - Zone 5a regions)

  • 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

23 Apr 12, kate (Australia - cool/mountain climate)
I have to say I have had the best month for growing Radish this year! All of them have been a success and It's amazing. Soooo happy! I would love to add photos to show everyone!
04 Jan 12, Val (Australia - cool/mountain climate)
I cannot grow radishes, carrots or parsnips. Tops look great, but nothing below the soil. What type of soil should I concentrate on, type of fertiliser etc. I have fluid off the worm farm, is this ok to use.
12 Jan 12, kate (Australia - cool/mountain climate)
Hi! I had the same problem with just putting the radish seeds in the ground. I found it easier to germinate them first. I put the seeds into a wet tissue and then popped it into a ziplock bag until they germinated. Once they germinated (6-10 days), I put them into my soil and VOILA.... growing very well! This trick can be used for all seeds! Let me know how you find this.. Kate
02 Jul 12, Ash (Australia - temperate climate)
This was the same problem with me too last year. Then i notised that few plants with no shadow whole day grows well down under and lots of plants with shadow for even a short time in a day also remain smaller raddish. So this year i planted all under full sun and all good now.
14 Dec 10, Harry (Australia - temperate climate)
My radishes grow with long green stems coming out of the ground as seen in the pic. However, despite the rather large sized stems, the radishes are small or in other cases, not even there. Can someone please help???
02 Jul 10, Martin (Australia - temperate climate)
My radish seeds germinate OK but when the young seedling emerges something is eating them. My cabbages are similarly being eaten and some leaves are mere stalks. I never see the culprits even at night time. I suspect cutworms because I put a small barrier around the last two emerging plants and they seem to be surviving. If cutworms are my problem how do I control them?
03 Jul 10, Tassy Michele (Australia - cool/mountain climate)
Hiya Martin, Had the same problem with lettuce and broccoli -- found the culprit/s were garden birds, swallows and wrens (obviously love the fresh new growth). I covered my new plants with 1.25l drink bottles with the neck cut off -- also acts as a mini hothouse. Have you considered slugs and snails? Good Luck.
27 Feb 10, Carol (Australia - temperate climate)
Hello, My name is Carol. I am the wife of a farmer, J.Thompson, we grow all different types of fruits and veg, we grow a lot of carrots, tomatoes, snow peas and radish. All those rules and tips are nothing like the real deal. Basically depending on the type of radish, you use sufficent fertilizer, you dig a hole, place your seeds about 3-5cm apart (they need room to grow!) and give them 600mLs of water everyday. After about 2 weeks you should be finding some results. If nothing has changed and there is still no signs of radish, it is a dodgy brand of seeds, you are not giving it enough sunlight, it is just a dodgy seed or you need to take better care of it. THAT is the real deal. Do not believe any of that scientific stuff! it is just nature. Thankyou I hope your radish grow successfully.
01 Jul 10, Yasmin (Australia - cool/mountain climate)
Thankyou for the help Carol! :)
22 Jan 10, Chris (Australia - temperate climate)
my radishes seem to grow with the roots above the surface. The ground is a clay but I have it quite loose with some organic matter. would it be best to leave them as they are or to build the soil up around the base of each plant?
Showing 111 - 120 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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