Preparing the soil
Start by preparing the soil by applying three to five barrow loads of compost or manure for each plant you want to grow. This is best done in the Autumn but can be done in early spring so long as the manure isn’t too strong.
In Spring, apply a good granular fertiliser like Growmore or Chicken Manure to the area about a fortnight before you will be planting out.
Plant your young plant into the garden when the first true leaves appear or when roots begin to grow through the peat pot (usually 7-10 days after germination). Handle with care as the plants will be set back if they are damaged during transplanting. Protect your plant from wind and night frosts.
Setting & selecting the pumpkin
Getting a pumpkin set as early as possible, if possible by mid-July is crucial. The earlier the pumpkin is set, the longer it will have to grow until harvest. This is why we recommend you pollinate by hand.
First select a female flower; they are easy to spot because they have a small pumpkin at the base. Early in the morning, locate a freshly opened male flower, pick it and carefully remove the outer petals to reveal the stamen which is covered in pollen. Next, find a newly opened female flower and gently apply the pollen from the male flower to the stigma of the female flower.
If the weather is on your side you should achieve successful pollination, if not the bees will hopefully have done it for you. It is recommended that you reposition pumpkins when they have set. A pumpkin’s position on the vine is an important factor. The stem often grows at an acute angle to the vine but for optimal growth you want that angle to be perpendicular to the vine. If you do not have a pumpkin set at right-angles to the vine, you will need to gently and gradually adjust the angle over a week or two until it is in the best position. Be very careful not to damage the fruit. when you do this.
If one plant has several strong vines you could have as many as twelve pumpkins growing on the plant by the end of July. To get the big ones, you need to cull to just two or three per plant. Many growers will only let one fruit grow to maturity on each plant.
When deciding which pumpkins to keep, measure each pumpkin’s circumference at the widest point regularly with a tape measure and select the one that is growing the fastest. Young pumpkins that are round and especially tall grow the largest, so shape also plays a part in your selection.
It is important to control growth and start pruning your plant early in the season to discourage random growth. Prune each main vine when it has reached 3-4m (10-12ft) beyond a set fruit. If you have a pumpkin on a vine that is 10 feet from the main root, cut the end of that vine once it is 20-24ft long. This is of course dependent on the space you have and harder pruning can be done if you have limited space. Side shoots off the main vines should have the tips cut out at about 12ft, again dependent on your space. Side shoots should be trained at right angles to the main vine for easy access to vines and pumpkins.
During the growing season you need to apply water-soluble plant foods on a weekly basis. Early season fertiliser would ideally be Superphosphate, followed by a high nitrogen feed such as Sulphate of Ammonia then a balanced fertiliser before fruit set. By August switch to a high potash feed (either Sulphate of Potash or Tomorite). Be careful not to over-fertilise, as this will do more harm than good to your attempt at growing a giant. Measure your pumpkins at least weekly to check their progress. Measure the circumference of your pumpkins parallel to the ground around the widest part of the pumpkin. Then measure over the top in both directions from ground to ground across the middle from stem to blossom end. Measure across the other way in the same manner. Once you know the total inches of these three measurements added together, simply multiply by 1.9 to attain an estimate of the pumpkin’s weight.
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