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Vegetable musings from Sea Spring Seeds

Growing cucumbers outdoors


Outdoor cucumber trial

Outdoor cucumber trial at Sea Spring Seeds


Outdoor cucumber trial at Sea Spring Seeds

For years, I’ve been on a quest to find outdoor cucumbers that are productive and produce tasty fruit that are good for eating fresh, both out-of-hand and in salads. Sea Spring Seeds  currently only sells one outdoor cucumber. This is  Marketmore 76, an open-pollinated variety from the States, and though it’s a good yielder of good tasting fruit, it seems rather mean to have only the one outdoor variety in our catalogue.

Unhappy with such a paltry offering, we conducted a trial in 2015 to see if we could find other cucumbers to equal or better Marketmore 76. Fortunately, there are quite a few varieties being touted for growing outdoors, and in the end, the number in the trial was whittled down to a manageable eight varieties. Since we were already selling Marketmore 76, it was included as the standard against which everything else could be compared. Passandra – an all-female parthenocarpic variety we promote for growing inside a tunnel or greenhouse – was a wild card choice also included in the trial. I had read somewhere that Passandra could be grown outdoors and still produce a decent crop, and my curiosity demanded that this claim be tested.

The trial was started as transplants by sowing seed in an unheated greenhouse on 14 May. On the outdoor part of our nursery, a bed five feet wide was fertilised with pelleted chicken manure, rotovated and covered with black plastic mulch for weed control. Holes in the black plastic were made every 45cm, and on 6 June, five plants of each variety were transplanted through these holes.

The base of each transplant was then watered to settle the soil around the roots. Once they had become established, the plants were given a laissez faire style of care, except for watering during dry spells. The first harvests were made on 7 July, and the fruit were regularly picked for the duration of the trial, which was terminated on 4 September.

Unless otherwise stated below, all varieties were non-parthenocapic and monoecious (that is, they produced both male and female flowers on the same plant). Information was collected on a number of characteristics, including fruit yield; best size for fruit harvest; skin toughness; length of main stem; side shoot development; and mildew resistance.

Results of the outdoor cucumber trial

Results, starting with the highest yielding variety:

Passandra (F1)
Yielded 55 fruit per plant (fruit picked when 150 to 160mm long); plants very vigorous.

outdoor passandra

A harvest of Passandra in the Sea Spring Seeds outdoor cucumber trial.

Other comments: parthenocarpic and all-female flowering; early to produce; fruit have a rough skin finish, and will need peeling; blossom ends tend to be bulbous and seedy; plants displayed good mildew resistance.

Crystal Lemon
Yielded 51 fruit per plant (fruit picked when 40 to 50mm in diameter); plants are vigorous growers.

Other comments: andromonoecious; fruit shape short and ‘boxy’ in longitudinal section; skin is light-coloured and tough; late to produce fruit, though there is compensation later in the summer; susceptible to early mildew infection.

Crystal Lemon2-web6

Crystal Lemon cucumber cut in half to show internal flesh.

Crystal Lemon cucumber

Harvested Crystal Lemon in the outdoor cucumber trial.

La Diva
Yielded 43 fruit per plant (fruit picked when 135 to 170mm long); plants very vigorous.

Other comments: parthenocarpic and gynoecious, with some production of male flowers; skin tender enough to be eaten without peeling; slight bitterness in some fruit, but not enough to be a problem; plants display good resistance to mildew.

SM 5341 (F1)
Yielded 35 fruit per plant (fruit picked when 100 to 120mm long); moderate plant vigour.

Other comments: parthenocarpic; pickling variety suitable for eating fresh if picked small; early to produce; tough skin that needs peeling.

Yielded 33 fruit per plant (fruit picked when 80 to 85mm long); restricted plant growth.

Other comments: fruit are particularly small; they are bitter and have a soft texture; tough skin needs peeling.

Marketmore 76
Yielded 30 fruit per plant (fruit picked when 160 to 170mm long); moderate plant vigour.


Harvest of Marketmore 76 in the outdoor cucumber trial

Other comments: tough skin needs peeling; somewhat late to produce fruit.

Bush Champion
Yielded 14 fruit per plant (fruit when 180 to 200mm long); restricted plant growth.

Other comments: sweet taste and crunchy texture; tough skin needs peeling; late to produce; susceptible to early mildew infection

Peticue (F1)
Yielded 10 fruit per plant (fruit picked when 170 to 215mm long); restricted plant growth.

Other comments: tough skin needs peeling; late to produce; susceptible to early mildew infection.


Conclusions and further actions

Based on our results, La Diva and Crystal Lemon have been added to the 2016 Sea Spring Seeds catalogue. Yields of both were very good, while taste and texture were more than acceptable. To get the best from Crystal Lemon, fruit must be harvested when quite small, otherwise eating quality will deteriorate. Considering its parthenocarpic tendencies, La Diva should do well under cover, and we will be trialling it inside one of our polytunnels in the summer of 2016.

Cucumber seed packs

Sea Spring Seeds seed packs of Crystal Lemon and La Diva cucumbers.

Marketmore 76 yielded well and, therefore, has been kept in the catalogue. Despite its awful name, I was tempted to include SM 5311, but in truth, it would have been difficult convincing gardeners to grow a pickling cucumber for the purpose of eating fresh.

The surprise of the trial was Passandra, a parthenocarpic, all-female hybrid. Normally recommended for growing under cover, it proved to be a good yielder outdoors – the production of 50+ fruit per plant is certainly an admirable feat. Admittedly, the skin had a rough finish, though peeling it off easily remedies the condition.

Of greater concern, however, was the bulbous shape of the fruit’s blossom ends. These bulbous ends were full of seeds, detracting from the overall eating quality. Seediness and bulbiness are not traits usually associated with Passandra, which is usually grown on its own undercover. In our outdoor trial, the plants were surrounded by varieties that produced male flowers, and we assume pollen was carried by bees to Passandra’s female flowers, stimulating seed formation and probably causing the fruit’s bulbous shape.

Given the yields we got in our trial, we have high hopes for Passandra as an outdoor variety; and will try it again outdoors in 2016. This time, though, it will be isolated to eliminate the possibility of pollination, which should then result in seedless fruit with a normal shape. That’s the theory, anyway. And if it does perform  well – as we think it will – then we can unreservedly recommend Passandra for growing outdoors.