How to Grow Seedless Watermelons

by Juanita Schulze

Seeded watermelons are delicious but seedless melons are the best!

I had a customer tell me that his seeds did not grow--both the hybrid and its pollinator. He  wanted a refund. I told him I would not refund him and he threatened to leave bad reviews unless I did. I don't give in to threats. This is the best thing you can say to me for me not to help you. (Some customers ask me to send more seeds. I never do this because if you messed up the first batch of seeds you will probably have the same success with the second batch).

There are many things that can go wrong when you garden, the least of these being the seeds themselves. As gardening guru Bob Webster likes to say, "Gardening is a lot like gambling,  only the odds are worse."

Now I did check this customer's weather conditions and it was too cold to plant these in his area. Most seeds need a soil temperature of around 70 degrees Fahrenheit. I have no way of knowing what his soil temperature was, but when the day time temp does not get above 75° and night time temps drop to the mid 40s, then I am pretty sure it is not warm enough to plant this watermelon. For germination, this watermelon needs the ambient temperature to be between 80 to 90 degrees Fahrenheit. 

And not all watermelons are the same. He told me others he had planted had come up already. You cannot judge one variety by another. Seedless watermelons are highly specialized seeds. They require a lot more attention.

I think he direct sowed them. If he did this, then there is no way he maintained the proper temperature. I always start my seeds as transplants first unless they are beans or corn.  It takes a lot of patience and practice to know how to grow seedless watermelons properly.

I decided to start some seedless watermelons for the fall. I am going to let one of my new team members handle this by reading this website and seeing what she can do. I will not give her any guidance.

I am going to be planting the same variety as the customer. It is the Orange Crisp.  The customer's complaint is only two or three seeds germinated. This included the pollinator. I have told him if my seeds do not grow then I will refund his money.

Tips On How To Grow Seedless Watermelons

It will take about 14 days to germinate. Then we go to a hardening off process

We will take photos of our process. I know, I have said this before and then failed to follow through. We will do it this time.

We will start this project around the sixth of July since this is the new moon and the best time for planting transplants. We will go by the phases of the moon. Then they should be ready to transplant out when the next new moon shows.

The team member will start these in CowPots. We will use CowPots since we will be able to drop these into the ground without disturbing the roots. We will have to be careful since CowPots dry out fairly quickly.

We will check our soil temperature with a temperature gauge and not guess.

We will perform a soil test on the soil so we know exactly where it stands. We will probably do this with in the next few days in case there are any changes we need to make to the soil.

What are Seedless Watermelons?

First of all, there is really no such thing as a "seedless" watermelon. Instead of black seeds, they will have white pips that are almost unnoticable and edible.

Seedless watermelons, are more difficult to grow than regular watermelon varieties. However, they can be grown successfully with some extra care and management. The seedless trait is a result of a traditional cross of an open pollinated seed with two chromosomes and an open pollinated seed with four chromosomes known as tetraploid.

Black seeds can be formed if the watermelon comes under stress from lack of water to excess heat.

How To Grow Seedless Watermelons

First thing when you learn how to grow seedless watermelons is to make sure the soil temperature, in our case our germinating mix, is at least 70 degrees Fahrenheit and the ambient temperature is 80 to 90 degrees. Unless you live in the deep south, you will most likely need some sort of hothouse or a cold frame of some sort.

You may want to read our article on germinating seeds before you start.

Keeping them in the house or on a window ledge will not work. How many of us really keep our homes at 80 degrees? It just dawned on me that there was a time when I could not afford to keep the house lower than 80. But for the most part, we do not keep our homes at 80 degrees and definitely not 90 degrees. 

We put our pots in a tray so we can bottom water. The mix we use draws up just what it needs from the tray. If you try to water the plants from the top, you take a chance on dislodging the seeds.

Plant the seeds 1/4 inch deep. Measure; do not guess. We have made a four inch ruler with 1/4 inch marked on it. These are free with seed orders from our website. 

Once this is done, you will fill the tray until the pots just start to float. Wait an hour and they should absorb enough water so they do not float. Then keep the tray 1/2 to 3/4 of the way filled with water.

This is it. In about 14 days or so, you will have seedlings.

8 Days from Planting


To show you how easy this is, we had our newest team member, Linda, hired on Monday, plant these on Tuesday. For the first three days here, all she did was do seed starts for us. Most everything she planted has come up, is coming up or needs more time. Some of the items, like hot peppers, will need three to four weeks to germinate.

Orange Crisp Watermelon seedlings 7 days old. As you can see, they have not all come up yet. Patience is needed to learn how to grow seedless watermelons and everything else!

These are our seedlings.Some have come up. They still need another week to germinate. If you notice, I forgot to have Linda put these in the CowPots.

They are looking good. I think some people do not realize that you have to give your seeds at least the exact number of days to germinate. A few come up, they lose patience and say the seeds are bad.


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