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
  • Cherry radish
  • French Breakfast radishes

Small, spicy tasting root vegetable usually round but some longer varieties. Available in a range of colours between red and white.

Very easy to grow. Good for a child's first garden as seedlings appear in two or three days. Sow between other vegetables as they will mark the rows until the slower germinating plants appear.

Culinary hints - cooking and eating Radish

Wash well and remove leaves and roots.
Use raw in salads or on their own with bread and butter.

Your comments and tips

06 Jan 23, Andres S Del Villar (USA - Zone 8b climate)
You may want to do a soil test so you know what you have and what you don't. Using all that potting soil you may need some lime mix in there. If your organic is right out of the bag and not aged you just have to wait several yeas before it's broken down well.
23 Dec 22, Andres S Del Villar (USA - Zone 8b climate)
Hello, I have been growing vegetables here in Manteo, NC for the last 10 years, zone 8b. I believe your planting times are at least 30 days too early . I plant most of it by seed outdoors maybe and that may be the reason.
05 Jan 23, (Australia - temperate climate)
Read the paragraph at the bottom of the page. It is general advice, There could be many different sub climates within the same climate. Generally it is about soil temperature required for germination.
12 Dec 22, (USA - Zone 9a climate)
what radishes grow best in zone 9A?
18 Dec 22, (Australia - sub-tropical climate)
It is about picking the variety you like.
04 Oct 22, ELIZABETH (USA - Zone 7b climate)
I had no idea you could actually eat the green end of a radish until i started gardening myself this past year. doing research on the when and hows has taught me so much and the green end of the radish was actually really good! Great flavor! thank you for gardeners and gardening! So much peace in my life now!!
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.
22 Sep 19, Gerty (USA - Zone 7b climate)
My radishes came out too small or not developed a full bulb/root at all. I used a peat based potting soil and compost + vermiculite also amended with fish/kelp emulsion. I am growing them in 6 inch deep flats with proper drainage holes. The variety is Cherry Belles, Rover, French Breakfast. Planted them in late summer for fall.
25 Apr 20, Dr. Peeper (USA - Zone 9b climate)
Sounds like your soil is too rich, probably in nitrogen.
Showing 1 - 10 of 16 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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