It’s time for Medwyn Williams to sow giant vegetables

Growing mammoth veg is great fun and a good way to get youngsters involved

Growing a giant pumpkin or marrow can really get kids motivated as they can see the size increasing on an almost daily basis. Another good way to keep their interest is to scratch their name fairly deep in the skin with a nail or other sharp object. As the veg grows in size so does their name as it heals over.

I’ll be sowing both pumpkins and marrows this week as they need a long season to put on weight. I’ll plant mine indoors in a shallow tray filled with some Levington F2S compost, with the pointed end facing downwards. Before pushing it into the compost I like to chip off the front bit to allow the moisture to enter the seed case.

The problem with these giant marrow and pumpkin seeds is that the seed case can be hard and very thick, so if you bury the whole seed it can often rot before it germinates. We grow a large amount of these to sell as plants and my daughterin-law, Alina, is excellent at germinating them. She pushes the seed into the compost a third of the way into the seed tray, then places the seed tray on a heated blanket.

Within three or four days you can pull a seed out and usually you’ll be able to see the white radicle showing through at the end. At this stage remove the seeds and plant deeper into a 7.5cm (3in) pot of compost, with the radicle end facing downwards.

This way you’ll get a far greater germination rate and the seedling leaf will quickly emerge. More often than not the empty seed case will be attached to the seedling leaf and I like to remove this seed case as it can cause part of the leaf to rot.

Another job that needs doing this week is to plant up my giant Cornish cabbage and giant ‘Klimaro’ red cabbage plants. They need to be spaced out at 2m (6ft 6in) apart to ensure plenty of room for expansion.