I'm an amateur gardener and I've tried growing sweet peas, yard long beans, cucumbers with no results. The plants grow but never bear fruit. The only thing that grows in my soil is tomatoes. Can anyone explain why only tomatoes grow in my garden?
It seems to be a pollination/fertilization issue, because you've said all your plants flower, but only the tomatoes go on to produce fruit. That would indicate there's nothing wrong with the soil ph nor your fertilizer, if you're using any. Are you treating the tomatoes differently compared to the other things you're growing, such as, growing in a different area of the garden, or watering more regularly and so on? Tomatoes don't need insects to be pollinated, movement of air will do it, but cucumbers, for instance, do need pollinating insects, and without those you may need to pollinate by hand. As for the beans, you haven't said which variety of beans, and some do require insect pollination, though many don't. I'm also not sure what you mean by 'sweet pea' - sweet peas in the UK are a flowering climbing plant, grown for flowers, not for fruit. If you think there might be a lack of pollinating insects in your growing area, it would be wise to consider what flowering plants you can grow nearby that would attract them.
The other possibility is that the flowers are dying or falling off before they're able to be pollinated, and that might be a water or temperature issue.
UPDATE: I suddenly noticed you mentioned yard long beans as the ones you're growing - they do, indeed, need pollinating insects to fertilize the flowers. Good in hot areas and pretty drought tolerant, so we're back to the major problem being lack of pollinating insects. In relation to flowers to attract insects, native, or wild plants, and herbs (plants used for medicinal or culinary purposes) are usually the best ones to use, provided they're not too invasive.
You should look into hand pollination as well if the local pollinators are not cooperating. I had this same issue with my cucumbers and squash when I first started my garden.
- First, identify the male and female flowers. This is easiest to do by
just looking under the base of the flower:
- Females will have what looks like a miniature squash or cucumber under the flower.
- Males will have a plain stem.
- Pick a male flower and expose the "anther" on the inside of the flower.
- Rub this gently to the center of the "stigma" on the inside of the female flowers.
- You can use one male flower for several females.
You will be producing in no time, and hopefully from every female flower.