There can be few crops that are worth more apiece than melons and watermelons. These are so much better home grown than bought and yet are not commonly grown in most kitchen gardens. Melons are not actually difficult to grow, and it’s only a little more effort to get really good ones, watermelons are difficult but worth it. First though forget about growing them outdoors, without some sort of cover, cold frame or cloche, I have tried for twenty five years and the results have always been pathetic.
However give them some extra warmth and shelter and suddenly they thrive and crop remarkably easily. How well they crop depends on many factors but of course enough sun comes into it, and good soil conditions etc. but I reckon the apparent complications all come from inappropriate advice, in other words melon growing suffers badly from years of the wrong instructions.
The major problem is the accepted advice is all about how to get uniform crops of moderate sized fruits. Thus the recommendations of nipping out the tip after the first four leaves to get four shoots, each of which is to have a female flower on it pollinated on the same day. All in order to get four equal sized fruits, of saleable size and then to clear the beds. No more fruits or they will all be too small, and no less as fewer bigger fruits would make less profit. And all must be got to be equal in size because if one gets bigger than the others it may cause them to stop or even abort. so the necessity of starting them off together. And then with good culture all four ripened and sold together or as near as can be.
But I, and maybe you, don’t sell melons but eat them. And despite our best efforts we are often not as practiced or as well provided with the right conditions as professional growers. Thus to aim to have four melons per plant is not what we want and all that advice is redundant.
From the kitchen gardeners point of view four per plant, if achievable, is not the optimum as it necessarily wastes four shells, pith and seeds instead of say two lots or one. And if fewer bigger fruits are produced there is even less waste as the ratio of skin and uneatable rind to flesh is much more favourable with bigger fruits. (The volume goes up by the cube while the surface area goes up by the square so huge specimens waste little on rind whereas tiny ones are almost all rind.) And of course the strain on the plant is to produce all the seeds not the flesh so aiming for fewer fruits means the plants should be able to swell the remaining ones the more, not just to the same weight of four but of five or six. And surely you do want to grow really big ones!
True if you let the plant make but one shoot this may go on growing without flowering, and stopping does encourage the more productive sideshoots. But don’t stop plants as recommended after just four leaves but leave them to grow and only if no female flowers are being produced after a dozen leaves then stop it. Very rampant plants still may not produce female flowers and only few males, so then nip out all the tips and reduce it’s feeding. If only male flowers appear then the plant is probably too hot, so ventilate more. (Shading may be needed under glass in the very sunniest weather, but not often enough!) When a female flower (there is a wee melon just behind it) appears then pollinate it either with pollen on a brush from a male flower or by rubbing a male flower (with yellow pollen on wee stalky bits) onto the female sticky cushion in the middle. Then place a cork mat or wooden cushion underneath so that later as the fruit swells it will have something clean, dry and warm to rest upon. Tiles and stones hold the damp so wood is better though I find expanded polystyrene packaging best of all even if an eyesore. Melons do not like being moved once swelling commences, though it is better to support them when spotted than to leave them dangle. Melons get bigger if held up in a net or stocking than if hanging. This also stops them dropping off and bursting when ripe.
You see there are few fruits eaten so ripe they drop off but the melon is at it’s best then. A week or so before ripening little tiny cracks appear round the stalk end as it prepares to fall off, at this point withhold further water except to stop wilting. By now even the very best of the commercial ones would have been picked as they have to travel and if the stalk comes out they rot. But at home we can risk leaving a melon until it is so ripe it drops. It is best then chilled a tad before eating. The perfume will be exquisite, but too powerful for some more used to unripe shop bought fruits.
But I leap ahead. As you or I are probably happy with a few huge melons and then some small ones coming over a few weeks instead of all at once then sporadic setting and swelling of fruits is no great problem. Thus melons can even be planted and effectively left to ramble, though if by any unlikely chance more than a few fruits set at once and start swelling it helps to thin them out to no more than three.
Unlike cucumbers melons are not worth forcing for very early or late crops, those ripening with plentiful sun are the only ones worth having.
They are not tricky to germinate just needing warmth and do best grown undisturbed in individual pots sown in early spring. Their compost needs to be moist, rich, open (aerated not muddy or claggy) and quite limey. The crucial point though is to keep the stem neck out of the compost and dry as if wetted it usually rots. (Though the stem will layer and root elsewhere.) That is why melons are often grown on mounds, and always watered from underneath; it keeps the susceptible neck bone dry.
As the plants grow add dilute liquid feeds to their water such especially seaweed and fish emulsion. These are of great benefit but do not use rank ones, such as fish emulsion or manure tea, once the fruits are near ripening as these may taint. Top dressing their compost is also useful as they will root up into it but keep that stem neck dry and uncovered. If it does get rot you can try to dust it gently with sulphur but a safer bet is to try and root the stem further on, preferably with bottom heat.
There is no doubt that melon plants grown with bottom heat are the best and most productive. I have had excellent results from a cold-frame placed on top of a freshly made and well earthed over compost heap. Likewise I have grown melons in tyres, dustbins and deep freezer bodies all warmed by deep fillings of mostly grass clippings, with straw and compost to mix them up a bit. The beauty of grass hot beds (use horse manure etc if you have it, I have the grass unprocessed by a horse) is they give off a warm dampness melons just love, and feed them for free, the disadvantage is the fillings, plus their toppings and the plants in them sink and cause problems with the trailing stems getting pulled. However the syems are easy enough to tie up to strings if you can’t let them sprawl.
Without a hotbed grow melons in big tubs raised up on staging or similar as they will be warmer than in the ground. Of course you can add heat to the ground with soil warming cables but that makes it all too expensive. However it is warmth as much as light they crave. Then surprisingly water. In old Persia, and other regions, they were often grown on floating beds on lakes. The tops and necks were bone dry but rooted in rich moist soil only saved from water-logging by it’s depth. But that is in full hot sun, they don’t like it cold and wet. Thus they are only happy under cover in the UK.
However they can be grown sort of outdoors if the soil is pre-warmed and kept warm with black plastic sheet laid down and a cloche, or with a second sheet of clear plastic suspended above this on sticks or similar to make a wide low tent. With plastic sheet underneath and a cloche or tent the soil gets very warm by early summer and melons can be planted. The plants need a lot of water when the weather is warm, and need the sides of the tent lifted to allow plenty of ventilation on hot days or they scorch.
Under glass where they build up and over-winter red spider mites will be a problem. They love melons and watermelons and massacre them. Get the predators Phytoseulis persimilis by mail order (see small ads) and they work if introduced in time. Otherwise you need near continuous misting under the leaves to keep the pests under control. I find that plants rambling amongst ground cover suffer less than those growing in bare soil.
As to variety. Avoid the hardier and reputedly easier such as Sweetheart, Romeo and so on, even the popular Charentais and go for the more difficult but very rewarding such as Ogen, Galia, the traditional Blenheim Orange, the heritage Nutmeg and Jenny Lind. These will stagger you with their size, intoxicating syrupy sweetness and overwhelming perfume.
Equally impressive and needing similar but even warmer conditions are watermelons. The healthiest and most prolific, heavily cropping plants I’ve ever seen were on sandy flats running next to the beach on a Caribbean island. These revel in lighter sandier composts than the rich ones made for melons, and rather resent the confinement of even large pots though they can just be cropped in very big tubs. They are best grown by the plastic sheet super-cloche come tent method suggested above for melons or allowed to run over a bed under cover say in a poly-tunnel, the average greenhouse is likely too confining to get really big fruits but will manage one or two modest ones.
Watermelons are grown similarly to melons but are more tender and simply die away at the roots if the soil temperatures drop too low, and they are rather prone to root infections anyway. I’ve heard of watermelon tops being grafted on other more resilient cucurbit roots, in Spain, –has anyone tried it, I’d love to hear? One other item of difference with melons though is that watermelon plants are always best left unstopped to run, and should have all other fruits removed once one gets past golf ball size as your chances of getting more than one worth having are slim. Watermelons take even more water than melons, they need less feeding though, and are ready when they give a hollow sound when tapped. There are many varieties but few are really well suited for the UK summer even under cover mostly preferring it much hotter. Sugar Baby is probably the best currently, the old fashioned Charleston Grey does fairly well, as does Pasteque à confiture a French one originally for preserving; it’s excellent if small and seedy. There are dozens to try and any might just be THE one, so go on have a go.