Growing Watermelon

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

(Best months for growing Watermelon in New Zealand - cool/mountain regions)

S = Plant undercover in seed trays T = Plant out (transplant) seedlings

  • 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 21°C and 35°C. (Show °F/in)
  • Space plants: 60 - 75 cm apart
  • Harvest in 12-17 weeks.
  • Compatible with (can grow beside): Sweetcorn, Sunflowers
  • Avoid growing close to: Potatoes
  • Melon flower
  • Watermelon

Large, round or oval, smooth green skinned, delicious, sweet pink fleshed melon.

Some have stripes on the skin.

Some varieties will produce fruit up to 14 Kg (31 US pounds).

Harvest when the part in contact with the ground is turning yellow and the fruit sounds hollow when tapped.

Watermelon needs plenty of room to grow as it sends out long vines

Needs a long warm season to mature.

Culinary hints - cooking and eating Watermelon

Cut up and eat in slices.
Use to make fruit drinks.
Use in fruit salads.

Your comments and tips

03 Sep 20, Kay (Australia - sub-tropical climate)
What fertiliser is best for watermelons?
08 Sep 20, Danlo Troth (Australia - temperate climate)
My grandfather was always using old n dry cow poo. Just make sure to really dig it in and mix well into the dirt.
09 Sep 20, Anonymous (Australia - arid climate)
Old dried out cow poo has probably lost a lot of it's nutrient value, leached out with gravity and rain etc. Any manures need to be made into a compost material asap to retain as much of the nutrient as possible. Or you dig it into your soil over 6-12 weeks and with air water and turning it, it breaks down into the soil. The greatest benefit of organic material put back into the soil is it makes the soil loose and friable, which means it then drains well.
04 Sep 20, Anon (Australia - sub-tropical climate)
Just look for a general garden fertiliser. There is not that much difference in them
16 Jul 20, Jodie (USA - Zone 9b climate)
My grandkids want to grow watermelon with the seeds from a fresh watermelon. It's mid July and we're in zone 9b in the Arizona desert. Thank you in advance. Happy planting!
23 Jul 20, colleen (USA - Zone 10b climate)
Fun project! Be aware that seeds might be sterile from a store-bought melon (and likely won't be true to seed). But worth a shot for the surprise factor, I think. They should try the paper towel sprouting method to test viability. If seeds sprout, get them in the ground by August and there should still be time for fruits. They'll need plenty of water in hot weather (mulch helps too).
11 Jul 20, Cathy Mallen (USA - Zone 10a climate)
I am wondering what watermelon will grow in zone 10 (the coastal portion) Thank you.
29 May 20, Farai Mutsago (South Africa - Summer rainfall climate)
Where can l buy watermelon seeds in Polokwane or Mussina
26 Apr 20, Phillip Bellis (Australia - tropical climate)
We are having a watermelon growing comp. at a school just out of Darwin. Seedlings are just a week old in pots. When would be the best time/age of seedlings to transplant. Weather is warm at 32-35 C and dry but being watered 2x a day. Thanks
27 Apr 20, Another gardener (Australia - tropical climate)
The leaves that come out on germination are called the cotyledons, then come the first true leaves. When you have the 3-4 set of true leaves transplant them. I grow things in 500gm margarine containers, when the seedlings have grown to the above stage (like about 100mm high and round) the soil in the container has lots of roots in it to hold the soil together when you take the plant out to transplant, try and keep that all in tact. Best to tip upside down into one hand gently. Don't over do the nitrogen - you will end up with a lot of vine.
Showing 1 - 10 of 264 comments

I have a watermelon growing and setting teeny baby fruit but they all wither and drop off within a week of setting. Any ideas?

- Phoebe

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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. GardenGrow 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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