“You can’t grow Watermelons in the UK…… can you?”

If I was to tell you that I don’t actually like the taste of Watermelons, it would be a fair question to ask me just why I dedicated so much time last year to growing them and indeed, why I plan to do the same this year.

The answer to this question is made up of a few key factors. Firstly, I picked up a cheap packet of Watermelon seeds in my local garden centre. They were half price and that alone was enough for me to pick them up and add them to my basket on a bit of a whim! Upon researching how to grow Watermelon’s in the UK, it was amazing how many sources I came upon that said it couldn’t be successfully done. I read numerous articles stating that Watermelons are incredibly difficult to grow in the UK and that you would be better off sticking to other Melon varieties.

This insistence that growing Watermelon’s would be (literally) fruitless and a waste of time did not put me off, quite the opposite in fact. I love a challenge and the more I read that it couldn’t be done, the more I wanted to do it!

I also find there to be a strange kind of romance to growing exotic fruits here in the UK. To be able to stroll down to the allotment and be greeted by glossy, green fruit, content with growing (albeit under a poly cover) in my little corner of the world, which happens to be the south coast of England, hundreds of miles from their own natural habitat. Then, after months of love and care to be able to harvest this fruit, take it home and cut into it to find that sweet, red flesh. A true reward for all that hard work and attention.

When I decided to write this post about growing Watermelon’s in the UK, I originally thought I would list all the ways that I read that it could be done, as there are a few slightly different methods I researched. However, I quickly dismissed this idea as firstly it would have been far too long and confusing to try and list all methods and secondly, I want this post to be a tried and tested method that I personally have found to work for me. I want to know I am writing about something I personally have tested and found to work, so that I can be sure of the information I lay out here! The growing guide I am going to share with you here is how I managed to successfully grow Watermelon’s.

Obviously, this method may not work for everyone in the UK. I am lucky to live on the South Coast, where we tend to get the best of the UK weather. Lovely warm summer days drift into mild evenings and this definitely helped my Watermelons. Other areas of the UK may well not experience such favourable conditions and so what worked for me may not work for you, but as gardeners, all we can do is cross our fingers and try!

When I began my Watermelon journey last year, armed with little more than a cheap packet of seed and a handful of internet guides I honestly wasn’t expecting to achieve much. The variety that I chose to grow was “Valentina”. As mentioned above, I chose this variety as it was half price at the garden centre. Up until I spotted these seeds, I had never researched or considered growing Watermelon. I wish I could say I selected this seed on the basis of knowledge and intelligence, but I am afraid that is not the case at all! Nevertheless, back in late February 2017, I opened this little packet of seed and buried 6 individual seeds on their side in 3″ pots of seed compost. I sowed each seed approximately half an inch deep, covered them with compost and watered them well.


At the time, I did not own a heated propagator and so I simply placed each individual pot on the floor in a corner of my bedroom in an area where they were away from possible temperature fluctuations. To my surprise, the seeds were fairly quick to germinate and within a week, I could see the tips of the tiny seedlings just starting to poke their heads above the soil.

Once the seedlings had unfurled their first “baby” leaves, I moved them to a windowsill to ensure they received plenty of light, as I wanted to avoid them becoming too leggy. Over the next few weeks I left them to their own devices, just performing the usual checks such as ensuring they were sufficiently watered. I repotted each seedling into a larger 5″pot once I saw the first true leaves beginning to grow. I wanted to ensure that the plants did not become root bound. Once in their new pots, the seedlings went from strength to strength and it was only a few days later that all my seedlings fully developed their first true leaves.


By now, it was early April and though it was still far too early to move the Watermelon plants outside, I had some work to do on their final outdoor position. I had already selected the sunniest area of my allotment as the “Watermelon zone”. Now I wanted to prepare the soil for these little plants. I did this by digging the soil very well, removing all weeds and stones as you would before planting any young plants or seeds and then adding in some pelleted Chicken manure.

I then had to consider that Watermelon’s are a tropical plant and as such, they need warmer conditions than what is natural here in the UK. The soil really needed to be warmed up before the Watermelons were planted. To achieve this, I covered the soil with some black, weed resistant plastic material. This was actually beneficial for more than one reason. Firstly, the black material would absorb the heat from the sun and as a result, warm the soil below it. Secondly, it had the added bonus of stopping any weed growth that may have occurred while the bed was waiting for the Watermelons to be planted out. As well as this, I then covered the whole Watermelon bed with a mini polytunnel style seedling cloche, the same as this one here. Again, I did this to help to raise both the ground and air temperature surrounding the Watermelon bed.

By Mid May, the Watermelon plants were doing very well at home on my windowsill. I had repotted them again into 7″ pots and the plants were now looking strong and healthy. The weather outside had warmed up considerably and I made the decision to plant them out. My Son (in full Stormtrooper get up) and I headed over to the allotment with the strongest three Watermelon plants.

It was a very warm day and as I sat in the seedling cloche the difference in air temperature was very obvious – it was, to put it mildly, exceedingly tropical inside the cloche, perfect for the Watermelons! I started the transplanting by cutting a hole through the black weed resistant material, large enough to take the entire pot size as I wanted to minimise root disturbance to the plants.  This way I could simply tip them out of the flower pots they were living in along with all the soil and then pop everything into the newly dug planting hole in the seedling cloche.

I managed to fit three planting holes inside the seedling cloche, each was spaced approximately 60cm apart. I then added some compost into each hole and carefully placed two of the three plants into the holes, back filling each one and firming them in gently. My Son had been watching me do this with interest and he insisted on planting the third plant, which he did with the kind of style and flair that only a Stormtooper can!


Once the plants were in, we watered them well and then closed up the seedling cloche. Over the next couple of weeks I kept a close eye on the young plants. On the days where it was very warm I opened the vents in the cloche to avoid it getting too warm and I also watered the plants well in the evening just as it was starting to get dark so that the water didn’t scorch their leaves or evaporate in the heat. All our love and care did the trick, as by late May / early June our little plants were getting bigger.

I had researched two methods of growing Watermelons. In the first, I was advised to train them up a cane to avoid the fruit resting on the ground and to save space. The second method advised allowing the Watermelons to trail along the ground so that the weight of the fruit didn’t cause them to weigh the plant down. As this was my first attempt, I decided to try both methods and I left the two plants on the outside to trail, while inserting a cane for the middle plant and lightly tying the plant to the cane to train it upwards. For reference, I actually decided I preferred the trailing method and this is the method that I will be solely using this year.


It was mid June when I checked on the plants and noticed to my excitement, that we had flowers forming on our plants. I kept checking these almost daily and a few days later I noticed our very first Watermelon starting to form behind one of the open flowers. Needless to say I was almost beside myself! I couldn’t believe that we actually had fruit! I did know that now was a crucial time for the survival of the fruit though. Watermelon flowers do need to be pollinated in order to grow. If a female flower is not pollinated by a male then the growing fruit will simply rot away, it will not develop into a larger Watermelon without pollination. As my plants were housed in a closed up cloche, the Bee’s could not do this crucial job for me and so successful pollination was entirely down to me.

To pollinate the Watermelon’s, I had to firstly locate the male flowers. It is easy to tell the difference between the male and female flowers. If you look just behind the flower head, the females will have a slight bump, where the fruit is forming. The males do not have this bump and are formed on a normal, straight stem.

Once I located the male flowers, I took a small paintbrush and carefully rubbed it over the centre of the flower, making sure to cover the bristles in pollen. I then located the female flowers, with the tiny fruit growing behind them and transferred this pollen from the paintbrush to the centre of each flower. I tried to get as much pollen as possible from the male flowers into the females, as I wanted to give my Watermelons the best possible chance of successful pollination.


It was now a case of crossing my fingers and hoping! Out of the female flowers that I pollinated only about 30% did actually go on to develop bigger fruit. I did lose approximately 70% of the others, which I am sure was down to inadequate pollination by me – what can I say, I am not as efficient as a Bee! However, as it was only my first attempt, I am pretty proud that I did actually manage to pollinate the remaining fruit successfully.

As the days ticked past and the majority of the fruit shrivelled and died, I concentrated on the remaining ones, which were getting bigger by the day. I kept the plants well watered and I fed them with a liquid seaweed based fertiliser. It wasn’t long before the tiny fruits had grown to the size of a small egg.


At this stage, all I did was continue with my regime of watering, feeding and opening the cloche vents if the days got too hot. Once the fruit had actually set, they were pretty quick to grow larger. By Mid July, our first Watermelon had grown to what turned out to be pretty much its final size. It wasn’t huge, but it was large enough for us and definitely something to be proud of. I placed the fruit on cardboard to prevent it from coming into direct contact with the ground as I was trying to avoid it getting attacked by slugs or rotting if it was in constant contact with damp ground.


It is difficult to know when to harvest Watermelons and there are different theories online as to what the best way to tell when a Watermelon is ready to be harvested. I decided to look for two key tell tale signs. The first was the skin of the Watermelon. I was looking for my Watermelon skin to be a deep green and for the underside of the Watermelon (where it was resting on the cardboard) to have turned from a pale yellow colour to a deeper yellow.

The second sign was the sound of the Watermelon! By this, I mean that I carefully knocked on the Watermelon. I was waiting for the sound to turn from a metallic sort of sound to a dull “thud”. At the end of July, our first Watermelon was showing all the signs of being ripe. The skin had turned deep yellow and when I tapped on it, I got the long awaited, dull, hollow sound that I was waiting for.

It was still nerve wracking actually cutting the Watermelon from the vine though, I was worried about whether I had misjudged the signs and was cutting it down too early. The last thing I wanted to do after all those months of love and care was fall at the final hurdle by cutting an unripe Watermelon from the vine. As soon as I had cut the Watermelon, I rushed it home and tentatively cut into it. It was red, it had worked!


The next step was, of course, the taste test. Now, as I mentioned at the start, I actually don’t like Watermelon, I wish I did, but I have tried it so many times in the past and it is just not for me. So for this task, I had to enlist the help of my two most honest critics – my children! Both my Son and my Daughter love Watermelon and would be sure to give me a brutally honest review. As they each bit into a freshly cut slice, I watched their faces with the kind of scrutiny usually only reserved for when trying to detect a lie. As their eyes lit up and they went in for a second bite, I breathed a sigh of relief. “They taste like real Watermelons!” Exclaimed my son in surprise! My Daughter was too busy munching through her slice to make any comment at all, other than “Mmmm.” It was safe to say that our first Watermelon was a success!


Over the following couple of weeks, we managed to harvest a further two Watermelon’s from our plot, both of which were equally as delicious (according to the Children). Although three fruit was not a huge amount to reap from all the care, time and attention they had taken to grow, they were without a doubt well worth it. We will definitely be growing them again this year – in fact, the seedlings are already coming on nicely on my windowsill as I write this!

This year, I will tweak a couple of things, such as improving my pollination skills and not bothering with trying to stake any plants, instead allowing them to all trail along the ground. I am hoping that if I can perfect my pollinating that we may be able to increase our Watermelon yield this year to three or four fruits from each plant, as opposed to the one fruit per plant that we achieved last year. Mind you, even if this year turns out to be the same as last year and we only get two or three usable fruit, I can say without doubt that it will all be absolutely worth it. I have grown a lot of fruit and veg in the past and I can honestly say that I think the Watermelon’s would be in my top three for pure enjoyment and pride in growing!


2 Comments Add yours

  1. Adam Leone says:

    I tried once – wasn’t very successful :/


    1. Annie says:

      Oh no 😦 Will you be giving it another go? My main priority for them this year is to improve my pollination technique to try and yield more fruit as apart from that, my plants did pretty well.


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