Watermelon Guide

So, you've bought a watermelon kit. Here are some helpful tips to ensure your growing experience is a success!

watermelon growing indoors on a windowsill

Hand Pollination

Did you know that watermelon plants have separate male and female flowers? To ensure successful pollination and fruit set, consider hand pollination. Gently transfer pollen from the male flowers to the female flowers using a small paintbrush included with your kit. This technique will ensure fruit production when growing indoors.


@coco_and_seed Growing some 🍉 indoors. Lets hand pollinate this one. I missed two other female flowers but managed to get this one #Indoorgarden #watermelonplants #hydroponicsbeginner ♬ original sound - coco_and_seed


Identifying Male and Female Flowers

Male flowers typically appear first and outnumber female flowers about 7 to 1. Male flowers have thin stems and lack a round base (ovary), while female flowers have a miniature fruit at the base, indicating the presence of ovaries. This is where the magic will happen. When the flower is open, typically first thing in the morning you'll want to get your paintbrush ready to collect the pollen from the male flower and then "paint" or transfer it to the open female flower. Once pollination is complete you'll know when the female flower closes and the male flower dies. You'll have about a 24 hour window.


watermelon growing indoors on a windowsill

Pinch Your Flowers

Pinching flowers, particularly in the early stages of growth, can redirect the plant's energy towards producing larger fruits. Pinch off some of the early male flowers to encourage stronger vines and better fruit development. You'll get on average 2-4 watermelon fruit per plant!



Pruning watermelon plants can help manage vine growth and improve airflow, reducing the risk of any pests finding their way to your leaves and wreaking havoc. Remove any dead or diseased leaves and trim back extra foliage to promote healthier plants and larger fruits.

Sunlight Requirements

Watermelon plants thrive in full sunlight, requiring at least 6 to 8 hours of direct sunlight daily. Ensure your mason jar garden kit has a prime location to receive the best view of direct sunlight to support healthy growth and fruit development. This is typically on the south, south west, or west facing windows.

watermelon growing indoors on a windowsill


Knowing when to harvest your watermelons is crucial for optimal flavor and sweetness. Look for these signs:
- The underside of the watermelon turns from green to yellow.
- The tendrils near the stem start to dry and turn brown.
- Thump the watermelon – a deep, hollow sound indicates ripeness.

Harvesting Technique

Carefully cut the watermelon from the vine using sharp scissors or pruning shears, leaving a few inches of stem attached. Handle the fruits gently to avoid bruising or damaging them. To help clean the scissors after washing with warm soapy water try extra cleaning with rubbing alcohol, especially if using to prune other plants.

mini watermelon with full grown seeds on kitchen counter

Finally Save Your Seeds

To save watermelon seeds for future planting, scoop them out of the ripe fruit and rinse off any pulp. Spread the seeds on a paper towel or screen to dry thoroughly, then store them in a cool, dry place in an airtight container until the next time you want to plant. You can use replant packs available in the Coco and Seed store for the extra supplies you may need!

Some bonus things to note

1) Watermelon prefers warmer temps 75+ degrees farenheit. If you're growing these in the fall, winter, or particularly colder climates be sure to keep it away from drafts (open windows), single pane windows, etc. 

2) As your fruit begins to grow be mindful of making sure there is enough hydroponic plant food or some kind of water soluble plant fertilizer. 

3) Just as you want to be mindful of making sure there is enough plant food also be sure to balance out with plenty of plain water. This is to reduce excess buildup of nutrients so you can "flush" the system.

4) Although watermelon are sprawling plants if you don't have the horizontal room you can create a trellis for the plant to vine and grow upwards. Just be sure to create plenty of support for the melons as the weight will be too much to support on its own. 

5) Have some leaves falling off as the fruit grows? That is normal, don't worry! All the energy will be going towards growing the new watermelon so pruning excess leaves may help focus the plant's energy towards growing these big melons.


With these tips in hand, you're well-equipped to nurture your watermelon plants to fruition. Happy growing, and enjoy! Be sure to share pictures online tagging @coco_and_seed #cocoandseed on Instagram