The Best Gardening Tips, Growing Guides, Recipes & More!

Melon Sowing and Growing Guide

Published: 27th April 2023

Melon Growing Guide


Melons, like cucumbers benefit from warmer temperatures so unless you have a heated greenhouse it is better to delay sowing until late April or early May. A sowing made in late April for planting in an unheated greenhouse in late May will produce a good crop of fruit from the middle of August. Early varieties like ‘Mangomel’ will start to produce ripe fruit from early August from a mid-April sowing.


A kitchen windowsill or a heated propagator is perfect for germination. You can use either a seed tray (with or without grids), or a few small pots – filled with a seedling specific compost. Make sure you moisten the compost before planting your seeds. Plant your seeds evenly apart from each other with at least 1cm between each seed and sprinkle with a dusting of compost on top. Cover the seeds with a plastic bag if they are on a windowsill – this will keep the conditions warm and moist. If your seeds are in a heated propagator this won’t be necessary.

Melons need to be kept very warm in the germination period. A temperature between 20-22 degrees Celsius is optimum.


Prepare to transplant your seedlings after about 10-12 days. Your seedlings should have one leaf on them before you consider moving over to pots. 9cm pots are perfect for melon seedlings, and they can stay in these for up to 4 weeks. Your melons will still not withstand being outside at this point and will need to be kept inside on either a windowsill, in a conservatory or moved into a greenhouse/cold frame. Plants should not be moved outside into a non-heated greenhouse/cold frame before the mid-end of April. Melons have no frost tolerance and will not survive in a non-heated greenhouse or a cold frame if there were a cold snap.


Indeterminate melons must be planted in a greenhouse or conservatory in the UK climate to ensure strong growth and fruit development. Plants can be moved from 9cm pots into the soil, grow bags or a large pot (15 Litres in volume as minimum). 

  1. Plants should be supported on a bamboo cane and trained vertically or on a string attached to a horizontal wire running the length of the greenhouse. Female flowers will start to develop fruits when pollinated so do not exclude bees from the greenhouse.
  2. Plants can be grown horizontally but will spread significantly, up to 2m, so unless you have a large greenhouse it is best to grow vertically.


Harvest melons when the blossom end starts to soften and the aroma from the fruit becomes rich and fragrant. Mangomel changes skin colour from yellow to a buff/beige as it ripens and the aroma becomes intense.

back to top

Receive Gardening Tips & More To Your Inbox