Many people will not eat or grow Cucumbers because they are bitter to the taste. This is true of older varieties and is caused by a bitter gene which is part of the make up of Cucumbers.
Almost all the research that has been devoted to the Cucumber has been in and aimed at trying to remove this bitterness. The result of this research has been a host of new varieties that do not contain this bitter gene, or very little of it.
If you are harvesting bitter Cucumbers, the most likely explanation is that you are growing them incorrectly.
On no account let your Cucumber become stressed (lack of water, for example), they tend to bitter up.
If you grow the right kind of Cucumber, and keep the plant free from anything that might check their growth then you will have perfectly nutritious cucumbers that are crisp, refreshing pick-me-ups on a hot summers day.
However, if you want to be on the safe side, there is a trick for removing bitterness. This bitterness is almost all concentrated in the leaves, stems and skin of the Cucumber. If you remove one inch of the cucumber’s stem end and peel the skin back to a thin layer of flesh directly beneath the skin.
I have also found that scoring cucumbers with a fork makes the difference between faintly bitter and palatable cucumbers. You can try this out yourself. Peel a Cucumber. Take two center section. Score one and leave the other alone. Cut a slice from each and taste. You will find that the slice that has been scored is less bitter.
All this is aimed at making the cucumber less bitter, however you may well like bitter ones, in which case grow old varieties.
In the main there are three types of cucumber: field or standard ones, which grow quite large with a bright green color; smaller pickling ones with a more yellowish tone to the skin; and greenhouse forced varieties, which are bred to grow fruit in somewhat lower temperatures like the UK. I find in a good summer here in Oxford I can grow all three. In cool summers the outside ones do not do so well.
You can sow cucumber seeds straight into the ground, however I prefer to start my off in seed-trays and them pot them on until they are big enough to be planted out in the open or glasshouse.
I could list varieties here, but the best is to see what your neighbors are growing or which plants are for sale in your local shop.
Cucumbers are very heavy feeders so grow them in enriched soil with well-rotted manure or compost. Watch out for the usual pest and deal with them.