Growing Watermelon

Cucurbitaceae c. lanatus : Cucurbitaceae / the gourd family

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

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

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • P = Sow seed
  • Grow in seed trays, and plant out in 4-6 weeks. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 70°F and 95°F. (Show °C/cm)
  • Space plants: 24 - 30 inches apart
  • Harvest in 12-17 weeks.
  • Compatible with (can grow beside): Sweetcorn, Sunflowers
  • Avoid growing close to: Potatoes

Your comments and tips

04 Sep 22, (USA - Zone 10b climate)
March or Aug Sept
02 Aug 22, rhonda (USA - Zone 9a climate)
It is now the beginning of August 2022 and I was wondering if it is possible to grow watermelons from seed in grow zone 9a (Houston Texas) if I grow them in a giant pot and keep it in a shady area of my yard out of the extreme heat we are experiencxing now in Texas? I planted some seeds (direct seeded into the top of a compost pile I have in direct sunlight) they did germinate into very small seedling plants, but because the weather was hitting over 100 degrees they immediately died back. So I am attempting to grow some in a large pot and keeping them out of direct sunlight and seeing if they will continue growing, if so I will try to grow them vertically on a trellis. Has anyone else ever attempted such a experiment? If so, were they successful in getting a watermelon to grow out of season?
13 Jun 22, Fifita Filipe (New Zealand - temperate climate)
Will the seed collected from hybrid watermelon can be ok to grow in our garden???
24 Aug 22, Richard (New Zealand - temperate climate)
It will grow but will not be true to type. You don't know what you will get. Hybrids are produced by pollinating specific flowers with specific pollen. So when the hybrid grows fruit it is neither of these. It is a mix of both, just like our children. If we plant seeds from that fruit we have broken the hybrid chain. The result will be a lottery
17 Jun 22, (New Zealand - sub-tropical climate)
Hybrid is a cross of different varieties - plant these seeds and the watermelons may be hybrid or like one of the crosses.
15 Jun 22, Liz (New Zealand - sub-tropical climate)
Seeds saved from hybrids don't usually grow true.
08 Jun 22, Marlow (USA - Zone 9a climate)
I seem to have bottom rot on my watermelons. Two out of 3 are effected. I've read that it's because the soil is lacking calcium. I'll be getting a soil tester tomorrow to check the pH. What would be the best thing to add calcium to the soil? I just don't know if that would work or if I should start new seeds and plant in an area that already has the pH suitable for watermelons...
17 Jun 22, (USA - Zone 4a climate)
Probably too late now but use Epsom Salts - scatter some of this in your soil in future especially where you plant the seeds.
13 Jun 22, Sarah (USA - Zone 9b climate)
Maybe adding eggshells to the soil will help
26 Apr 22, Noelle (USA - Zone 10a climate)
Spacing for vertical watermelon growing? I have a 2x4 bed and planted watermelon on opposite ends on one side (Sugar Baby variety) and one on the center on the opposite side (Crimson) with the goal of having them grow vertically. I only expected three plants total but planted more seeds since these were older seeds. I now have eight watermelon plants that are growing beautifully. I don't want to thin, but I'm sure it's necessary. Any advice on spacing for vertical growth? I've read all sorts of different suggestions online.
Showing 41 - 50 of 350 comments

Hi I live just south of Perth and have planted organic watermelon seeds, the seedlings seem to be taking a lonnnnggg time to get bigger. They are planted on mounds and i have improved the soil (read sand) but am thinking maybe i did not improve it enough?? I am a newby having just turned into a garden nut, any help would be appreciated. Thanks

- Rosie

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