Why do some fail to grow a good crop of gourds? There could be a number of reasons but these are my top five.
1. Failure to notice the length of the growing season.
Are you located in an area that has a long growing season? Lucky you! This factor shouldn't have much affect on your gourd crop. Those in the northern climates with short growing seasons should check carefully how many days that gourd variety you desperately want to grow needs to get to maturity.
2. Using fertilizer with too high of a nitrogen content.
Nitrogen is great for getting your plants off to a good start, but if you continue down that road, you will have all leaves and no fruit. The first number on the fertilizer bag stands for nitrogen. If that number is a lot higher than the other two you've got the wrong fertilizer for your gourd plants. Use it on the lawn instead.
3. Plenty of flowers but no gourds develop.
Looks like you don't have any pollinators. Gourd plants have both male and female flowers and the pollen from the male needs a way to get to the female. Since the hard-shell gourd flowers open at night, you need some nighttime insects to do the job. You may need to do some hand pollinating.
4. Poor Soil.
Gourds grow best in a light soil with plenty of good organic material added. Enrich your soil with some well-rotted manure or compost.
5. Harvesting gourds before they are mature.
Sure your gourds grew fast and they look like the right size, but that doesn't mean they are ready to be picked. Gourds need plenty of time to mature on the inside to make a good hard shell. Don't pick gourds until the vines are dead and dried up.
These are my five top reasons for gourd failures. There are some other things that could affect your gourd crop, like insects and critters, disease, and poor weather conditions, but the majority of the time, my top five reasons are the culprits.