We started watermelons from seeds indoor to study how they grow closer.
This was our first vine plant and we had no idea how they would grow at all!
Right from the start, there were some challenges growing this plant inside our apartment.
A primary one is a lack of space for a huge pot of soil to support it.
Thus we chose to grow in KRATKY (non circulating hydroponic) method as they are easier to manage.
In a transparent reservoir like this, we could see how its roots progressed from a young seedling to fruiting stages.
TIP – Roots are massive, huge reservoir (pot) is better
Once the vine latched on to the support, it is very difficult to separate pot from the reservoir without harming the plant.
Thus, the largest possible pot or reservoir right from the beginning is best.
In soil, transplanting watermelon plants would be difficult as well.
OBSERVATION – Transplanting is difficult once vine latched on
About Pot or Reservoir Size
In a small reservoir like this 4L cookies jar, we are not able to support what the plant needs.
Some fruits and female flowers will be sacrificed.
As observed in the bottle below, roots mass is huge and they drink much especially on hot sunny days.
TIP – Need 5 gallon (19 Litre) reservoir for watermelon
We poured liquid nutrients from the top into the reservoir.
The transparent jar is shield from light to prevent algae growth.
TIP – PLAN AHEAD – BIG POT + SPACE TO SPREAD
In many countries, watermelons are grown on the ground on raised soil known as “hills” but in Singapore, many gardeners do not have land.
Thus we utilized vertical space and made adjustments as the plant grows.
TIP – Minimum 8 hours of strong sun
Last but not least, watermelon plants need long hours of brutal sun to grow better.
If there is insufficient sun, watermelon plants may not fruit.
TIP – Growlight Needed Indoor
From a very young plant, high-intensity grow light was utilized to supplement our short sun hours.
We tweaked our environment with grid frame and long L bracket hooks to allow these grow lights to climb with the vine as the plant grew taller!
Journal of our first watermelon plant
We sowed 2 seeds of strawberry watermelon on September 8 2019 at 3 pm and they germinated on the 10th.
Limited Packs of these seeds (Strawberry Watermelon, dwarf) available for Sale!
Emerging seed leaves showed on September 13.
Roots mass and more leaves within 10 days.
TIP – Set them in a permanent pot before vine starts (soil)
To save space, they were initially planted in cans and thereafter, moved to the big cookies jar (about 4 L ) to accommodate the growth of their rapid roots.
TIP – Easier to transplant from netcup for liquid-based plants
Netcup makes transplant easier.
We just plugged the plant into another reservoir without too much fuss.
About watermelon’s Flowers
Both male and female flowers are yellow in color.
To tell them apart, the female flower has an immature watermelon (ovary) attached beneath whereas the male’s flower is green and bald stalk.
Male flowers showed first before females.
Timing is KEY!
There were more male than female flowers, and they do not bloom at the same time.
Females tend to be slower.
When the female is ready, sometimes male flowers already wilted.
Male flowers bloom for two days and then they wilted.
About Hand Pollination
As there were no bees indoor, we pollinated the female flowers by hand.
The pollen in the male’s stamen is on the top and inner sides.
We found that it is easier to pollinate when we remove the male’s petals and used a rubbing motion on the female.
Thousands of pollen are needed to pollinate each female flower.
The rule of thumb is to use a minimum of 5 males to one female flower.
Quality and taste of the fruit also improved the more pollen applied.
This is the first successful pollination after numerous attempts!
Checked out how much it grew within 4 days!
More than one!
However they self abort before the fruits could ripen.
They were pleasantly juicy and slightly sweet, even though not fully ripe.
We had upgraded our reservoir size from 4L to 12 L, and are hopeful to see our fruits complete its fruiting journey.
Just for laughs, an NG behind the scene of a documentary project on December 9, 2019.
Filming crew focussed on watermelon’s flowers for this part.
Our grow lights are mobile as they are tied to the curtain rail and can be slid along as the plant grew.