Growing Cucumbers on the Balcony
I think next to tomatoes, cucumbers are one of my favorite plants to grow on the balcony. I use a trellis to get my plants growing tall so they take up less floor space and absorb late afternoon sunlight. They quickly produce a wall of large green leaves that turn my sterile grey concrete and brown brick balcony space into a lush jungle hideaway.
There are bush varieties of cucumber plants out there and I might have grown one or two many years ago. I don't remember. They are usually described by seed sellers as being perfect for containers and patios. But anything that grows short and bushy generally doesn't grow well on my balcony. I prefer the long vines of traditional cucumber plants.
Cucumbers are usually categorized as either pickling or slicing. And some cucumbers nicely fit into both categories. The perfect pickling cucumber is small, compact, stout... something that will pack nicely into a jar. It doesn't necessarily taste the best raw. They usually have prickly skin and gnarled skins. On the other hand, slicing cucumbers are much longer, usually have smooth skin and are great eaten freshly sliced.
Another term you may see that defines some cucumbers is "burpless". Cucumbers contain something known as cucurbitacin that concentrates in the skin and can give the cucumber a bitter taste, perhaps even causing an upset stomach. The concentration depends largely on the variety of cucumber and growing conditions. There are burpless varieties which have been bred to have less cucurbitacin, and therefor cause less gas in your digestive system. I've never grown any like that. When slicing cucumbers I almost always cut off the skin which should eliminate most of the cucurbitacin. Pickling is different. I leave the skin on for pickling.
Starting Cucumber Plants
The plant on the left was started on a window sill. And the plant on the right was started under a growlight.
I always start my cucumber seeds indoors. But cucumbers don't like being transplanted so I find it's best to do it before the plants get too big. Before the roots spread enough to fill the starter container. That way I'm not disturbing them too much when I pull them from their starter containers for replanting. Starting them under growlights has helped me produce much stockier plants than those I've started in the window sill and I find that helps with transplanting also. I've never had problems with cucumbers once they are established. It's getting them going that I find a bit more of a challenge.
Cucumbers will take a week to pop up from the soil once seeded, give or take a few days. Within a few weeks they're ready to go outside. I wait for the first few true leaves to appear. In the past I've been caught starting them too early so lately I've gone the other way and now I usually wait too long. In general, when they start shooting out tendrils, looking for something to grab onto, I know I need to get them out. But only when the weather is right. They are delicate plants that will not tolerate cold weather. I plant mine outside well after my last frost date. Even then I still have to be mindful of the weather. They don't do well on cool windy days. Especially when still growing, before they've anchored themselves onto the trellis. The winds beat them up constantly. Leaves get damaged. Hot days aren't much better.
Cucumber Flowers and Pollination
When it comes to flowering, cucumber seed will mostly be categorized as monoecious or gynoecious. This is kind of an important thing to keep in mind when selecting seeds for growing in limited space. The gynoecious plants are bred to produce mostly female flowers. The seed producers will add some seeds to the mix that are designed to produce only male flowers, or leave it up to you to plant them with another variety that has more male flowers. This is great for growing large crops of cucumbers. Not great if you only plan to grow one or two plants. The number of male flowers a gynoecious variety produces will vary. For small space growing, you'll have better luck with the traditional monoecious varieties.
The monoecious plants will produce a mix of female and male flowers throughout the growing season. And male flowers can pollinate the female flowers from the same plant. There is a bit of a pattern associated with when they produce more male or more female flowers which is most likely related to environmental conditions. I find the first few rounds of flowers tend to be more male than female. The female flowers show up in larger numbers once the plants mature. Generally, when I see a few female flowers open and ready for polenation, the same plant will have a few male flowers ready to go at the same time.
Wall of cucumber green.
Cucs on the vine, shaded by the leaves.
The flowers will not self-pollinate, unless you've purchased an expensive parthenocarpic variety which self-fertilize and produce seedless fruit. Cucumber polen does not float on the wind and will require the services of pollen loving insects for male to female transportation. I do not get a lot of insects up on my balcony so I take the time to hand-pollinate my cucumbers. It's doesn't take long and my success rate is quite high, relatively speaking. There have been times when I've neglected the balcony for whatever reason and cucumbers just magically appear without my help so maybe I do get enough insects up on my balcony to make it happen. Maybe by pulling all the male flowers and using them to pollinate the female flowers myself I'm actually preventing the bees from doing their job. It's always a nice surprise to pull back a few leaves on a cucumber plant and find a couple of giant cucumbers growing there that you hadn't noticed before.
Caring for Cucumbers
A trellis is the best way to grow a cucumber on the balcony. The plants will send out a couple of main vines that will grow several feet in length and eventually along those vines, other off-shoot vines will form. At intervals along the vines tendrils will reach out and wrap themselves around anything they can reach. A trellis made from poles 1/4 inch in diameter with 6-8 inch openings has always worked great for me but I'm sure there are other versions that work well and most likely even better. My only suggestion is to avoid netting made from plastic or cord unless there is tension on it to keep it tight. I prefer a sturdy structure that will not move much in high winds on my balcony.
Recently transplanted and doing well. I find cucumber plants are vulnerable to cold winds during early stages of growth and need protection from the wind.
For containers I use large plastic storage totes that I've converted into self watering containers, with false bottoms and a water reservoir beneath. Cucumber plants have lots of large leaves that transpire lots of moisture on hot, windy days. So a self watering container is my cucumber growing container of choice.
The trellises I build over my containers typically extend 3 or 4 feet wide and maybe 5 feet above the container. I take the time to train the vines along the poles of the trellis. Once they "take" they happily follow it along. When they reach the end I just loop them up to the next level. I tie the vines up here and there while they find something to grab onto. Once they get too bushy I find I have to prune some of the offshoot vines, or just snap off their growing tips. There are only so many nutrients to go around, and only so much sunlight space on the trellis.
Cucumbers are very thirsty plants. They also appreciate full sunlight but don't seem to crave it as much as other balcony crops, like tomatoes or peppers. On particularly hot days when they start to wilt a little in the heat, the leaves can burn in the sunlight if the plant starts to dry out, even a little. The problem with this is it becomes common to panic and overwater the poor things causing more root issues that reduce water intake and make the plants suffer even more. More reason to use a self-watering container.
When it comes to soil nutrients, I don't get overly fussed about what I feed my cucumbers. I give them the same general purpose vegetable fertilizer I give all my balcony plants. But as this is a plant grown for it's fruit, a fertilizer with less nitrogen should help promote fruit production over plant growth. I have a fairly lazy approach to gardening so it's 5-5-5 (or close to it) for my cucumbers, just like everything else.
Mildew has always been a problem for my plants and especially cucumbers. Like melons, they are highly susceptible to various forms of leaf mildew. So I prefer to choose varieties that have been bred to be resistant to mildews and other common diseases. I've tried a few different sprays and remedies to get rid of leaf mildew but it doesn't always work out. A plant that can tolerate it, even a little, will do much better.
Eureka
Talledaga
What I'm Growing
As I write this, I am starting another round of "Eureka" cucumbers from a packet of seed I purchased a couple of years ago. Eureka have amazing disease resistance and grow somewhat blocky shaped fruit that can be picked early for pickling or left to grow for a slicing cucumber. I actually find they grow a little too large for pickling. Doesn't stop me from using them for pickles though. I've had good luck with them.
Since a single packet of seed can last several seasons on my balcony I tend to just buy a packet of seed and keep growing that same variety every year until the seed runs out or they stop germinating. The previous cucumber variety I grew was "Talladega". It was not a good cucumber for pickling. The fruit were too long. But the skin was really smooth and dark. It was a nice slicing cucumber and I did alright with it, despite it being gynoecious. And I don't recall having any problems finding enough male flowers to get the job done.
Lately I've been using my balcony cucumbers to make refrigerator pickles. These are jarred pickles but not processed in a way that would give them a long shelf life. But that's ok because around here they don't last long and I don't produce so many that they crowd the fridge. Bucket pickles are another recipe to consider. Similar to fridge pickles but you skip the whole jarring process and just leave them in a tub or bucket in the fridge.