Growing cucumbers

Posted: Monday 9 July 2012
by Adam Pasco

Thank goodness for the greenhouse. When garden life has been one long round of heavy rain [...] it's been great having somewhere to continue gardening.

Secateurs cutting a cucumber side shoot

Thank goodness for the greenhouse. When garden life has been one long round of heavy rain, interspersed with lighter showers, and the occasional bit of drizzle, it's been great having somewhere to continue gardening.

Warm weather combined with regular rainfall has certainly raised humidity levels, making it quite uncomfortable for us to sleep at night. But I think these conditions have resulted in one of the best crops of cucumbers I've had for years.

By July, the main summer crops are always well established in my greenhouse. The south side is about 4m long, and into this space I fit a run of six different tomato varieties and two cucumber varieties, all growing in self-watering systems that both feed and water the pots. All I have to do is top up the water reservoirs with a solution of liquid feed every week or so.

My cucumbers are grown from seed sown in April, with the seedlings raised in a heated propagator. Choosing the right varieties to grow is important. I'm not a fan of mini-cucumbers, preferring to grow varieties that produce full-sized fruits. Why grow tiny cucumbers, when you can have large ones?

From experience, I'd always recommend choosing a variety that provides excellent disease resistance, particularly to powdery mildew, a devastating fungal disease that spreads over leaves, killing them and then debilitating the whole plant.

This year I'm growing cucumbers called 'Carmen' and 'Tiffany'. They're quite similar, so I’m hedging my bets by growing one of each rather than two the same. Both provide excellent resistance to powdery mildew, while 'Carmen' is resistant to many other problems too. Both varieties are highly productive, vigorous, free from bitterness, and have received Awards of Garden Merit from the Royal Horticultural Society for their outstanding performance.

'Carmen' and 'Tiffany' are vigorous climbers, so I'll train the main shoot vertically to the ridge, then horizontally along the length of my greenhouse, and back again if it grows well, later in the season. I only allow one main shoot to develop, and all the flowers and fruits form on this. Side shoots are pinched off to prevent competition and congested growth. A high-potash tomato fertiliser is perfect for greenhouse crops.

Red spider mites show up every year in my greenhouse. High humidity is claimed to deter this pest, so with luck I’ll not spot any for a few weeks, after which conditions will hopefully turn warm and dry. I think we deserve to have a summer, don't we?

However, I won’t leave things to chance, so I regularly spray the plants with an environmentally safe growth stimulant and pesticide called SB Invigorator, to prevent the mites from getting established. I also keep organic sprays containing fatty acids (soaps) at hand. It's essential to apply these with a pressure sprayer so that they can treat the undersides as well as the tops of leaves. I always give a really good dose to shoot tips, too.

These safe and organic sprays need to touch pests to be effective, as they only act on the surfaces of plants, and are not taken into the tissue of the plant itself. For this reason they also need to be applied regularly, to continue catching new pests as they hatch from eggs, so spraying should be repeated regularly, usually at weekly intervals.

After such a great start to summer under glass, I'm looking forward to bumper crops ahead.

Now, where did I put my umbrella?

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Talkback: Growing cucumbers
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mjtclayton 10/07/2012 at 16:45

My cucumbers are not turning green but stay a yellow colour anybody know why they are fully grow or still growing.

donutsmrs 10/07/2012 at 18:45

I'm also growing cucumbers in the greenhouse, last year I grew them outside. Like you it has been great having the greenhouse to keep on gardening, as I write this it is pouring down again. Tomatoes I had in hanging baskets have got blight because of this weather, I wish now I had taken them into the greenhouse. The greenhouse tomatoes are doing really well though. It does seem so unfair, when you think of the countries that are desperate for rain and never see it and we have more than we know what to do with.

ThePotsmith 11/07/2012 at 19:22

What variety of Cucumber are you growing mjtclayton?

Mine are Marketmore and are green so far though they are still in flower at the moment.

dunnejames 14/07/2012 at 13:04

This is my first year growing cucumbers in my greenhouse could anybody tell me what to look for when removing side shoots on my cucumbers. My cucumbers
are flowering at the moment

Adam Pasco 14/07/2012 at 20:52

Hi dunnejames, I'd recommend growing greenhouse cucumbers as a single main stem. When side shoots develop from the main stem you can just cut them back at their base.

However, if few cucumbers are forming you could let the side shoots develop long enough to flower and form a fruit, and just cut off the tip of this side shoot a couple of leaves past the fruit.

Hope this helps

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