Question
Hi, Im  growing watermelons.Do you recommend putting something underheath the melons to help protect them from ground rot.I've grown melons before and I had some success but I also loss  a lot for various reasons.I'm wondering if its best to put something under neath or should I just let them grow on the ground.They say you can normally tell when a watermelon is ready because of the ground spot.I've heard that its suppose to be yellow.But im wondering if you put something underneath the melon does that take away from the "ground spot" because its no longer sitting on the ground.I guess the rotting of the melons might depend on where the melon is grown?Maybe if the melons is on dry grass or dirt it makes it .Or maybe if the grass or dirt stays wet perhaps that;s why they rot.

Answer
A.M., my mysterious friend, there is no other way to say this.

To grow Watermelons, you have to know what's in your Soil. And the only way to know that is by testing it.  You need a Soil test.

It doesn't matter where you live.  How much you love Watermelons.  Not even how much you spend growing them.

Nope, the only way you can grow a great Watermelon, the only way to optimize its flavor and food value, or its size if you care about that (some people do), is by totally controlling what goes into building it.  Garbage in, garbage out.

The garbage we're talking about includes fertilizer.  Fertilizer is not plant food.  Because of the way molecules work, too much of certain elements completely stops others from getting into the plant.  It is way too difficult to look at your Soil and just know which fertilizer IF ANY you should use.  It is way too easy to screw it up.

That's not all.

You need heat.  You have not identified where in the world you want to grow Watermelons, so I can only hope you have the heat you need for the high sugar flavor to develop to its fullest potential.  Without the right air temperatures, and the long season it takes to sweeten all Melons, not even Einstein could grow a wonderful Watermelon.

Hilary Rinaldi, the green-thumbed "Weekend Gardener", says it best: "Watermelons need hot days, warm nights and plenty of room to spread out. Choose the right varieties for your conditions, employ these simple, organic techniques and you'll have a hefty harvest of juicy, sweet melons this season..."

I love Rinaldi's way with words.  Not only does she know what she's doing, she knows how to tell you.  Here's her Watermelon-growing webpage:

www.weekendgardener.net/about-us.htm

Let's go back to the Soil issue I mentioned earlier.

Soil testing is that single pain in the neck that no one ever wants to bother with.  People figure, I'll just fertilize the thing to death.  That way, it'll have everything it needs.

And it does not work that way.

Let's say you want to make a cake.  What do you have to do?

First, you get out the cookbook and find a recipe.  You check all the Ingredients and you make a list.  Then you look in the cupboard, and you check to see what you have.

Do you have Flour?  If you already have Flour, you don't need to buy any more.  

Maybe you already have Eggs.  Cross those off the shopping list.

But you need Sugar.  Vanilla.  Milk.  You go to the store and buy those.

Now you're home again.  Time to preheat the oven.

And I ask you, A.M. or whatever your name is, what is the oven temperature?

You have an oven, but you don't set the temperature?

Did you measure the flour?  Or do you just dump it in?

Do you even have a recipe?  

A.M., What's the pH of your Soil?

YOU DON'T KNOW!

A Soil test will tell you what's in the cupboard, what's the temperature, how long the cake is in there... These are things you need to know to grow Watermelons.  

But you have to get a Soil test.

AND....

I GUARANTEE YOU WILL BE ABLE TO GROW WATERMELONS IF YOU DO!!!!

But you may as well push this envelope.  After all, if you're going to go to the trouble to get a Soil test, why stop there?

Science is always coming up with new information we can use for stuff like this.  Watermelons are the world's most popular fruit or something like that, it's late and my mind is a blur, everybody grows Tomatoes and Watermelons and Pumpkins.  So let's move on to Watermelons 102: Mycorrhizae.

One of the more recent discoveries you may have heard about is that many plants have underground supply networks attached  to their roots.  You don't have to know how to pronounce it, you don't have to spell it, you just have to know about them.

And we can translate this word, mycorrhizae, into a user-friendly phrsae: FRIENDLY FUNGI.

Before you think ewwww, fungus, let me remind you that when you go to the doctor and get those shots in the arm, the syringe is filled up with FRIENDLY FUNGI called Streptomycin and Pennicillin and various other mold-ish microbes.  Some are good, others can kill you.

So it goes with Watermelons.

These are very complicated, highly effective nutrient delivery systems that grow huge, beautiful Tomatoes and gigantic, juicy Watermelons.  

Scientists have been going through the Plants kingdom, learning which Fungi seem to work best.  One Plant's friend is another Plant's foe.  

In the case of the Watermelon plant, Citrullus lanatus, some scientists did an experiment on the famous "Crimson Sweet" hybrid and learned that the right Friendly Fungus in your soil helps grow more Watermelons with more vitamins using less water.  This particular study was published in Plant and Soil magazine in 2003 ("Mycorrhizal colonisation improves fruit yield and water use efficiency in Watermelon grown under well-watered and water-stressed conditions" by Cengiz Kaya, D.E.B. Higgs, Halil Kirnak and I. Tas).  

Where do you get these Friendly Fungi?

Easy.  Just don't kill them.  Live and let live.  Use no Fungicides, no Herbicides, no Chemical Fertilizers. If you're not sure, you can innoculate your Soil with various cultures and they'll thrive if you're growing Watermelons.  Look for Soil that puts "Mycorrhizae" on the label.

No, they don't sell that in Home Depot.  Keep looking.

Now, Watermelons as a rule CAN NOT transplant.  You can start a lot of vegetables and flowers indoors, but NOT Watermelons.  However, in your region, if your Summers are short, you can compensate for the shorter growing season by treating the seedlings.  Soil temperature must be at least 60 degrees F first ?a week past the last frost. Let me know if you need this information.  

Finally, let's address your concern about the developing fruit and contact with the Soil.

Anything that grows that close to the ground, as all melons do, is inclined to catch a soil-borne disease sooner or later.  In fact, many commercial growers start their Watermelons early despite their transplant troubles.  Friendly Fungi to the rescue.  Growers tested 3 formulas of commercial Fungus treatments (yes, you can buy these): MycoApply, Mycor Vam Mini, and Myconate (formononetin).  Then they gave the Watermelons diseases. All the Watermelons grew better with one of them.

Organic growers, who use these Friendly Fungi to their advantage instead of slaughtering them, have less to worry about when it comes to potential blemishes from the Watermelon rind touching the Soil.  Watermelons are less inclined to be damaged, due to their thick outer rind.  But if you have all those nice Fungi to fight on your behalf, there won't be microbes defacing the fruit when you're not looking.  A layer of mulch or thin sheet of newspaper would not really hurt.  There are many other ways to identify the ripeness of one of these fruits.  Fear not.

One more thing: A.M., I specifically ask people to provide their approximate locations so I can factor that into my answer. In the Southeast, Rootknot Nematodes are a major cause of failure in these crops.  In the Midwest, wrecked Watermelons are often caused by an overdose of Ozone.  So if you write back, give me more information to work with -- are you in the South of France?  India?  Plano?  Kansas City?  It's a big world out there.  Enquiring minds need to know these things to give you a good answer.

There you are.  I hope it was worth waiting for.  I'd like to know more about uyour Watermelon patch problems.  Keep me posted and do send that zipcode or countrycode when you get a chance.  Now I'll go pour myself a nice, cold beer and a slice of... pizza.

L.I.G.