How to Tell If Watermelon Growth Is Going Well?

Watermelons are a sweet summer treat.

Watermelons are a cool, sweet treat during the heat of summer. Seeds of several varieties of this vining plant are available to home gardeners with a bit of space and a warm climate. The larger the melon, the longer it takes to ripen to maturity. Growing watermelon vines on a trellis or fence can help to minimize the amount of ground the plant needs to spread out. Also, mulching with black plastic will help to keep the soil nice and warm, which watermelons need in order to produce large, juicy fruit.

Things You'll Need

• Compost
• Shovel
• Water
• Fertilizer
• Insecticidal soap
• Iron phosphate granules
• Plywood or roof shingle

Instructions

1. Examine the leaves of young watermelon plants from time to time. They should be large, often green with white stripes and free from holes that insects can cause. Healthy plants produce healthy melons.

2. Watch for flowers and forming fruit. If flowers drop from the plant before they become pollinated, your plant will not produce fruit. To prevent this, grow your watermelons in the warmest part of the summer. You might also need to manually pollinate the female flowers with pollen from the male flowers.

3. Read the watermelon seed packet or catalog description to learn the mature size of your variety of melon: some watermelons grow to be very large, while others are smaller. A small variety will never attain the size of a large one. Knowing which variety you are growing and the expected mature size will guide you in knowing when to harvest your melons.

4. Search for brown, dry tendrils on the stem: this indicates that your melon is ready to harvest. At harvest time, the skin will harden to the point where it is difficult to force your fingernail into it. Also, ripe melons turn yellow on the side against the soil, so check for this coloration.

5. Thump melons by flicking your fingers against them to determine ripeness: some varieties of watermelon will have a hollow sound. However, this technique is not foolproof and can indicate overripe fruit for certain varieties.

Tips & Warnings

• Give your melons plenty of water by flooding the moat around their hill at least once each week.

• Check vines for signs of insect pests every week because plants that are stressed will not be able to produce large, healthy fruit. Control aphids and other sucking insects by spraying vines with insecticidal soap; control snails and slugs by scattering iron phosphate granules on the soil surface around your plants.

• Fertilize your young vines when flowers begin to form on the vines. Use a plant food with an N-P-K ratio of 5-10-10 to encourage blooming and strong, healthy plants.

• To pollinate female blossoms, look for flowers that have a very small bulb at the base. This is the young watermelon. Then search for flowers without this bulb: they are the males. Use a cotton swab to collect male pollen and then insert it into a female flower to transfer the pollen.

• Prop up developing melons on top of a flat board such as plywood or a roof shingle to prevent them from rotting on moist soil.

References

• University of Illinois Extension: Watermelon
• Oregon State University Extension: Why Do Flowers Drop Off Veggie Plants?