Plant Doctor Archive

Producing giant pumpkins

SOME workmates and I are having a competition to see who can grow the biggest pumpkin this year. We're all starting with the same variety of pumpkin seeds. How can I get mine off to an early start so that they have as much time as possible to grow huge?

IT doesn't pay to plant pumpkins out too early as they just won't grow if the soil is too cool. Usually late October is as early as you can get away with planting them out, and even then waiting another couple of weeks won't have any adverse effect on the final result.

You could start the seedlings off indoors in October, sowing seeds individually in small pots and growing them on a sunny window ledge.

Make sure you prepare the soil really well before planting them out, adding barrow loads of compost and manure. Think big, as one of the secrets to success with giant pumpkins is in the soil preparation. Ideally, build it up into a raised bed so there's good drainage. The soil then stays warmer, which encourages better root growth early in the season.

Shelter the young plant for the first few weeks after planting until the weather has settled - you could make a cloche with three or four stakes and a clear plastic surround, but make sure to leave the top open to avoid overheating.

Water and feed regularly - daily in summer when there are masses of leaves and the fruit is forming. And spray regularly with a fungicide like Bravo to prevent and control powdery mildew, ideally before it becomes a problem.

Another tip worth considering is once one or two fruits have set, remove all others to concentrate the plant's energy into producing one or two huge pumpkins rather than a whole lot of smaller ones.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.