When I first started our tropical garden I wasn’t sure if you could grow pumpkins in the tropics or not. Being from the northern, temperate, hemisphere, I associated pumpkins with the autumn harvest, Thanksgiving, winter storage, and spring plantings. I decided to just plant some seeds and see what happened. Most certainly, yes, you can grow pumpkins in the tropics and this post is about experiences, tips, and must-know facts, about growing pumpkins in a tropical climate.
Growing Pumpkins in The Tropics
A few words of wisdom, born of trial and error, successeses and failures, growing pumpkins in the tropics.
Growing Pumpkins From Supermarket Pumpkins
This is one of my favourite tricks for gardening on a tight budget in the tropics – grow plants from your supermarket-bought food. I do this all the time and it’s absolutely worth just having a go. Sure, some things fail, but that’s part of the learning process. Just try, you don’t know until you try.
Yes, you can grow pumpkins from the seeds in supermarket or store-bought pumpkins. In fact, all of my pumpkins started that way. Every time we eat a pumpkin, be it shop-bought or homegrown, the seeds go back in the ground. We don’t even care what time of year it is. They usually grow, some more successfully than others.
Male and Female Pumpkin Flowers
When your young pumpkin plants first start producing flowers, they’l likely all be male. Pumpkin plants produce a lot more male flowers than female. A week or two later, you’ll likely see your first female flowers, This also applies for cucumbers, corgettes, zuchini, any type of squash in this family.
If you have plenty of bees around and multiple pumpkin plants, all flowering, you’ll likely find your pumpkins become polimated naturally, but I like to make sure those precious femal flowers result in a pumpkin we can eat, so I hand pollinate pumpkin flowers.
Hand Pollinating Pumpkin Flowers
Pollen reportedly works best when it’s cool. Also your flowers are more likely to be fully open at dawn. So every morning, when you do your early morning garden inspection, coffee in hand, check for female pumpkin flowers. If you spot one, take action.
You need to get the pollen from a male flower, ideally on another plant. I don’t know if it’s possible to use a flower from the same plant, but it’s never worked for me. We always make sure we have three or more pumpkin plants to give us plenty of flowers of both genders.
To transfer the pollen to the female flower you can use a child’s paintbrush, a cotton bud (please choose bamboo stick buds, not plastic), or you can just break off the male flower, remove its petals and touch it to the female flower.
If pollination has been successful the ovary (containing the ovule and destined to become the fruit) at the base of the female flower will swell quickly. If the female flower isn’t pollinated this ovary, the potential baby pumpkin, will whither and die.
Protecting Your Baby Pumpkins
Maximise your chances of harvesting a healthy pumpkin by giving your pumpkin babies a little love. Ideally the pumpkin plant’s leaves will shade the fruit, they won’t like to be in the full tropical sun. If the leaves aren’t shading them you could maybe set something up with palm fronds or whatever you have handy.
Just as your pumpkins don’t like sitting in the sun, they don’t like sitting in a puddle. Try to lift them off the ground and keep their under-sides as dry as possible. This will help stop rotting and deter pumpkin-eating bugs. I just shove a couple of handfuls of dry sugar cane mulch under each fruit to lift it and let the air circulate a bit.
Conditions For Growing Pumpkins
If you have soil of any kind, with shade, full sun or part shade, try growing pumpkins, they might just work! Be careful not to grow anything near CCA treated wood or any soil contaminated with, for instance, lead from old lead paint or fuels. You don’t want to eat that. I mostly grow my pumpkins in a spot that gets some shade. “Full sun” in the tropics is pretty scary for any plant, unless it’s a cactus. Just about any plant likes fertile, rich, well draining soil. So don’t grow them in dust or in a swamp. A bit of a raised mound should stop your crops getting too waterlogged in the wet season.
Try not to dig and never leave your soil bare. Add nutrients from home-made compost or rotted manure, from the top, mulch well, and either keep the soil moist or water deeply. Don’t superficially surface water. Encourage all those good soil bacteria and plant other plants nearby to support each other. Soil is a mysterious thing. All of your gardening revolves around building the best soil possible. But rule #1, never leave your soil uncovered, is probably the most vital.
Pumpkins in the Wet Season
Our pumpkin vines grow like crazy during the wet and keep on producing flowers. However, I’ve not once been able to fertilise a female flower during the wet season. I don’t know why this is, but the same applies for all members of this family. I’ll keep trying. The latest I’ve harvested pumpkins is December, the start of summer, after this fruit is very likely to rot or be attacked by pests. The other time we harvest a lot of pumpkins is autumn into early winter, about April into May and June. That said, we have pumpkins forming in June too, but by that time some of our vines have died back, others are flourishing. That’s when the pumpkins that formed on the tail-end of the wet should be done. Honestly, most of our pumpkin plants come from seeds in our home-made compost, we never purposely sew pumpkins at a particular time of year, they just have their own little permaculture thing going on out there.
Pumpkins in the Dry Season
You will be doing a lot of watering to keep pumpkins alive or healthy through the worst of the dry, particularly towards the end of spring when heat and no rain make our gardening lives really difficult. I usually manage to keep mine alive to go crazy during the wet.
When to Harvest Your Pumpkins?
Depending on variety of course, you should notice when your pumpkins are “cured”. We grow Japanese pumpkins, so they turn from green and white to a little bit orange in the white parts. Other than that, if the vine starts to shrivel and brown, your pumkins should be ripe. The pumpkins in the photo above, taken in May, are just right and these will keep months.
If you have more pumpkins than you can eat, well done! Also, this is quite likely, pumpkin plants produce a lot of food. Pumpkins are one of the best storing foods out there, they’ll keep a long time, just keep them as cool and dry as you can. Make sure you don’t leave them out in the wet season rain sitting on soggy ground, they don’t like that.
So have fun growing pumpkins. We use them in soup, roast them, mash them, add them to just about anything. If you grow them in rich soil they will be nutrient-dense and add sweetness to any dish. My tropical garden is my laboratory (did you know I used to be a scientist?). Right now I’m experimenting with various types of pumpkin, different levels of shade and some exciting home made fertilisers and soil bacteria cultures. I never buy shop-bought synthetic fertilisers, they’re bad news for your microbes. I’ll let you know how we go!