Getting out in the garden can be so much fun! Choosing your plants, planning out your plot, and harvesting the fruits of your labors are all reasons that many gardeners love this spring to fall activity. But, even the most enjoyable hobbies needs a BIGGER challenge now and again. If you love thinking big, putting in time in the dirt, and reaping HUGE rewards for your efforts, then growing a GIANT PUMPKIN might be your next gardening adventure!
This Instructable will guide you through everything you need to know to grow the biggest pumpkin of your life. But, BEWARE, growing giants is an addictive hobby and once you get a taste of success you will only want to grow bigger and bigger. YOU HAVE BEEN WARNED!!! Have fun, and grow 'em BIG!
Step 1: Step 1: SEEDS...Choose Wisely
If you want a Huge pumpkin to compete with on a large scale, or just want to show off your growing skills to the neighbors with a massive Halloween jack-o-lantern that you grew yourself, you need to start with the right seed. Any brand of "Atlantic Giant Pumpkin Seeds" that you can find at your local garden store will grow you a big pumpkin. However, there are some extreme growers out there using their green thumbs to coax giants to over 2000lbs. These genetically tracked seeds sell at auction for hundreds of dollars each. So, go as thrifty or as spendy as you like; but, starting with the right seed starts your giant in the right direction.
Step 2: Step 2: Seed Starting/Germination
If you want to grow a Giant, you need to get that seed sprouted. Use soil specifically for seed germination (sprouting) to give your seed the best chance of starting strong.
Step 3: Step 3: Your Seed's First Tiny Home
There are many nifty ways to start your seeds; egg-shells, egg cartons, seed trays, jiffy pots, etc... However, Giant pumpkin seeds are very big and grow very fast, so they will not be hanging around in their first containers very long. This step makes transplanting easy on you and the baby GIANT as well. Using 2 large plastic party cups; label the outside cup with what specific seed you are using it for (fancy pants seeds...if you are using regular seeds you can skip the labeling) that way you don't lose track of what is growing in each one. Cut the very bottom off of the second cup and cut it top to bottom so it resembles an ugly plastic armband/bracelet/cuff. Place the cut cup inside the labeled cup and you are ready for soil and seeds.
Step 4: Step 4: Soil and Seed
With your Starter Cup ready to go, you need to add the seed starter soil and that baby giant seed. Pre-soak your soil with non-chlorine water. You should water it enough that when you squeeze a handful, you can see the water trying to come out but won't drip and the squeezed soil should hold it's shape.
-Fill the cup to the top without packing the soil down, the seed needs loose soil to fill with roots
-Poke your finger into the center about to the first joint ~1inch.
-Push the seed (pointy end down) into the hole until the top of the seed is the only thing showing at the bottom of the finger hole you made.
-Lightly cover the hole with soil. you can pat it down to get good contact but you DONT want to PACK IT DOWN! like we said before, the roots need loose soil to move through and fill up. BIGGER roots means BIGGER pumpkins.
Step 5: Step 5: Sprouting/Germination
Your seeds are planted and now is the worst part...waiting. But, to help speed the seed...see what i did there...here are some tips.
-Putting your seeds in the window or on top of the fridge will still work, but it is always better to control the environment yourself to maximize and accelerate a successful germination.
--Pumpkin seeds like temperatures around 85*F so a germination mat with a thermometer is very helpful. Plug the mat into the thermometer, set your desired temp, insert temperature probe into the centermost pot, put the top on and let it grow.
--Seeds like the dark so I put a towel over the top. This is not a required step.
--As soon as these little guys sprout you need to get them under the Grow Light.
Step 6: Step 6: Growlights and Transplants
Again, Grow Lights are not mandatory to grow a GIANT pumpkin. However, they can be very helpful. After your seeds have germinated, you need to get them under the grow lights. This will help them grow deep roots and not get super leggy (stretched out stems) because they won't be stretching up for sunlight. You will be giving them all the light they need to turn a nice green and grow out those first leaves, called "cots."
The job of the cots is to feed the first "True Leaf" the cots will spread out pretty wide and your roots will go deep very quickly under the lights so your seedlings will need to be transplanted into roomier containers within a couple of days.
Use the same moistening trick as when you were planting the seeds to prepare your potting soil, we don't want to drown our plants with too much water. Use a regular potting soil with good drainage amendments like perlite (white chunks like little rocks in the otherwise black potting mix.)
Put enough potting mix into the new container so that your sprouting cup is flush with the top. Leave the cup in the center of the new container and fill around it until the potting soil and the top of the cup is flush (the same level.) Again, don't pack the soil down, just pat it a little to get any air pockets out.
Now you can pull out the seed pot and you should have a perfect hole prepared for your transplant. Pull the inside cup (with the seedling still in it) out of the labeled outer cup. Put it (still inside the cut cup) into the waiting transplant hole. Gently lift the cut cup straight up and out of the new container; leaving your seedling perfectly in its new pot surrounded by fresh potting soil waiting to be filled with GIANT feeding roots.
LABEL, LABEL, LABEL!!! Make sure to label your plants so you know what you are planting, especially if you are trying with some spendy seeds. I like to use a 12" paint paddle...because they are free...and I am a cheapo. OR, you could integrate some 3-D PRINTING and print your specific Labels using TINKERCAD.
Put your newly transplanted baby Giants back under the grow light. Keep the light between 2" and 3" above your leaves. If they are too close they will burn; if they are too high your plants will stretch and have skinny weak stems. SHORT FAT plants are the goal!
Step 7: Step 7: True Leaves and Acclimating
The leaves that emerge from the cots are called "True Leaves." In your new pots, the cots will spread way out and get pretty big. your true leaves will grow fast and can be the size of your hand or bigger in only a day or two. make sure to keep an eye on them so they don't get too close to your lights and get burned.
After the first few true leaves have emerged, and the last chances of frost in your planting area have passed, you need to get your plants ready to be moved into the ground. They need to adjust to the outside weather just like people do. To prevent your plant from going into shock we need to acclimate the plant before we put it in the ground.
Find a shaded area where the plant won't be in direct sunlight, but can still be exposed to the brightness thereof. most people put them out on a shady porch or under a tree. Bring them back inside before it cools off too much outside. do this for a few days or a week, leaving them outside longer each day and even overnight.
Step 8: Step 8: Planting Time
Ideally, a giant pumpkin needs around 1000sq.ft. per plant, and that's for one pumpkin per plant as well. Realistically, not everyone has that kind of space. So, wherever you are going to plant, make sure the soil is well tilled, well drained, and gets good sun.
Fertilizers and soil amendments would be a whole different post so I will put some links to growers far smarter than me, at the bottom.
Pumpkins are very heavy feeders so they will need lots of water and lots of good organic matter in your soil. you can go as simple or as crazy as you want.
NOW THE GOOD STUFF!!
Just like our first transplant, dig out a hole so that the soil is flush with the top of your plant's current container. make sure the dirt in the bottom of the hole is nice and loose so the roots don't have to try and break up the dirt to grow deeper. Remove the container and gently set it into the hole. the FIRST true-leaf that grew out of the cots will point in the direction opposite of which way the pumpkin vine will grow. so point that first true-leaf away from where you want your plant to go. gently backfill the planting hole and pat it down. DONT SMASH IT DOWN! We want good soil contact with no air bubbles.
Use your hands to make a trench around the plant to hold water in the root zone when you water kind of like a bowl. This bowl should be wider than the spread of your current leaves. Water in gently to get that GIANT growing.
Step 9: Step 9: Vine Training
There are a tone of ways that growers train their giant pumpkin vines. One of the most tried and true methods is known as the Christmas Tree Pattern. The main vine is grown in a straight line away from the stump. Secondary vines grow out at a 90* angle from the main vine. As each new set of secondary vines grows out, it forms a Christmas tree pattern. Any vines that try to grow off of the secondaries should be pruned so that there isn't any crowding of the leaves. Each leaf needs lots of space they can be up to two feet across each.
Use small sticks to steer your vines in the exact direction you want them to go. Be gentle, these will break.
Many growers have different theories on how long the main-vine should be before trying to set a pumpkin. Really, it depends on how much space you have. YOU WANT AS MUCH PLANT BEHIND THE PUMPKIN AS POSSIBLE. The plant behind the pumpkin is what feeds the pumpkin.
Step 10: Step 10: Vine Burying
ROOTS, ROOTS, ROOTS!!!
The more roots you have the better. Evert leaf that grows will try to put down two roots; one from the bottom of the vine, and one from the top of the vine. If we can get more roots pulling water and nutrients from the soil, that's more weight going right on our pumpkin. So, we are going to help the process along and get as many roots as possible by BURYING OUR VINES.
There are two ways that most giant growers go about vine burying; trenching, and clumping. Both are easy, so it is really up to you.
Trenching is just digging a 3-4" trench in the direction your vine is growing and as it grows, you fill in the dirt over the top of the vine in the trench. Easy.
Clumping is waiting until the leaf and vine are grown out a little and the root node is almost or starting to show, making a pre-moistened soil-ball and smooshing it over the whole node area.
Whichever you choose, the additional roots will only benefit your Giant and your final weight. DONT skip this step, it really does your pumpkin a lot of good.
Step 11: Step 11: Pollination to Set Fruit
Having a big beautiful plant is great, but we want a pumpkin to work with. which means that we need to set fruit by pollinating a flower. Once your main vine has reached at least 8 feet, but preferably more like 12 feet, from the stump, start looking for female flowers. You will know it is female because it has a little baby yellow pumpkin right under the flower itself. the male flowers won't.
Once the female flower opens, it is ready to be pollinated. Find a freshly opened male flower and carefully remove the petals. Try not to be too rough so all that pollen (yellow dusty stuff) stays on the male flower's stamen (the long middle part.) Rub the stamen around and on all the female flower's Stigma and Style.
You can let nature do the hard work for you and have the bees get it done. This works just as well if you don't mind possible contamination of other kinds of pumpkins or squash. If you want to ensure a truly HUGE pumpkin, pollinate your flowers yourself and cover with a little cheesecloth to keep out other cross contaminating pesky pollinators (bees.)
Step 12: Step 12: Watch It Grow
YOU DID IT! You've put in the work and now you get to watch your baby grow into a GIANT. Once the fruit is set, you just need to position it at a 90degree angle from the vine so that as it grows it won't smash it. the vine will also rise off of the ground as the GIANT grows so try to arrange it so it has some slack as it grows; your vine will be working hard for the next 90 days. And yes, it only takes 90 days for these big guys to go from a flower to 2000lbs.
You and your pumpkin are now off to the races. During peak growing season, your GIANT can put on 5 to 40lbs per-day depending on how much you are watering and fertilizing. It is amazing to Watch!
There you have it. (Most) Everything you need to know about how to grow a Giant Pumpkin to compete with, put on your porch, or just show off. I hope you have as much fun with this hobby as I have. Have a blast, and grow a GIANT!
Step 13: References
This is an entry in the