Using your Cold Greenhouse or Polytunnel for Cucurbits
9th Apr 2005
If you have a cold greenhouse or even a polytunnel, you can now consider sowing a range of plants that are frost tender provided you keep an eye out for the weather forecast. The cucurbits family are certainly tender plants that would definitely suffer if they were exposed to a degree of frost. However, if you have some horticultural fleece close to hand, you should be able to harvest some lovely ripe fruit from the end of June onwards.
The cucurbits family includes the various cucumbers that are available as well as courgettes and pumpkins and the non edible ornamental gourds.
Pumpkins have been popular in America for many years and are now making steady inroads here as well. I find that of all the vegetables, the large or giant pumpkin is the one that seems to fascinate all the children particularly when you consider how popular Halloween has become here. There's no doubt that my three grandchildren love participating in carving out a pumpkin and turning into a ghostly flickering lantern. The good thing about this fascination is that we can, with a little thought, get some of the children really hooked on the growing. One certain way is to select a pumpkin for each child and when it"s the size of a small marrow, scratch their name deeply into the soft outer shell or skin. Any juices will soon stop running and the name will quickly dry out and calyx over. The fascinating thing for the children is that as the pumpkin grows to maturity, so the name swells out, leaving the children totally engrossed. The bigger the pumpkin, the bigger the name will be so you need to purchase seed of a variety that is capable of growing to large size. Atlantic Giant is one such variety and a good reselection of this one has the potential to grow to over 500lbs. With this very large variety I find it better to chit the seed first to make sure that they are going to germinate. Place some seed on a few layers of moist kitchen tissue in a container that has a sealed lid and cover over with some more moist tissue and place in a warm location. Check daily after about 5 days until the seed case opens and the radicle or young shoot appears. You can now plant each germinated seed individually, and on their edge in a 3 inch pot using some multi purpose seed compost. They will still take a few days for the roots to develop and the seedling to pop it's head through the compost. You will however know that they have already been chitted, or broken their dormancy, and everyone you plant should make good quality plants.
I generally start off my cucumbers in a seed tray using a seed based compost, again place each seed on its edge and about 1½ apart. The secret in germinating the large cucurbit seed is to have sufficient moisture within the compost to break dormancy without saturating it, thereby risking rotting the seed, water only when the compost appears to be drying out. There"s no doubt that the F1 hybrid all female cucumber varieties are far superior to the open pollinated types with the all female plant, every flower has a fruit behind it where as the others have a mixture of male and female flowers. You don't always have to grow the long standard type of cucumber. There are others such as Petita and Passandra which grow to just 6 inches in length and are often more adaptable for a small family. Why not be even more adventurous with your selection, the round to oval yellow fruited variety named Sunsweet F1 produces masses of lemon shaped fruits that are easy to grow and delicious to eat.
Courgettes and Marrows
I generally love to eat every vegetable, but I do tend to enjoy them better as an individual dish. This particularly applies to courgettes, I love them just plainly grilled and brushed with some olive oil rather than as a mixture in a ratatouille dish. The question I get asked quite often is 'when is a marrow a courgette and a courgette a marrow', generally, they are both one and the same thing although the breeders have of late been more selective with varieties for each class. The courgette is basically the young fruit of a marrow, selected when under 6 inches in length and before it's developed any large seed inside. The marrow is therefore simply a courgette that has been allowed to grow on to a mature size. The ones generally for sale at our supermarkets are the green types with 'Defender' being an ideal variety to grow. Two years ago, for my Chelsea display, I grew a new yellow kind called ‘Orelia', an F1 hybrid that is amazingly productive. This variety has hardly any male fruits therefore, as with the all female cucumbers, nearly every flower bears a fruit behind it and within days they are ready for harvesting. With all these fruits, space them out on the bench to maintain sturdiness and plant the cucumber in pots or Gro bags when about 6 to 8 inches tall. With the marrows and courgettes you have to be more in tune with the weather, plant them out only when there is no risk of any more frost and cover them initially with fleece or a cloche. If the plants are getting pot bound, and there is still a risk of frost, then you will have to continue potting them on.