Cucumbers

A yellow cucumber is usually over ripe. But a pale cucumber can also be caused by a virus, too much water, or a nutrient imbalance. Try adding some aged manure or compost to the soil around the plants.

Cucumbers depend on water and you need to make sure they get a consistent level of moisture. Your pots may be too small to retain the water. Consider transplanting to bigger pots. Cucumbers are also heavy feeders. Add a diluted liquid fish emulsion every other week during the growing season.

Cucumbers need a lot of water. Make sure to water often and add mulch around your plants to keep the moisture in the soil. The wooden garden boxes may dry out quickly in hot weather. Add compost or fertilizer to provide nutrients that the growing cucumbers need.

You’ll want to keep the leaves; they make food for the plant. As for pruning, you do not need to do any if you have a bush cucumber. If you have a vining cucumber that will be trained on a trellis, then pruning is a way to encourage yield and quality fruit. In this case, allow the plant to grow until it forms about 6 or 7 leaves on the main stem. A node is where the leaves connect to the stem. At these nodes, there can also be tendrils, a side shoot (also called a growth point, sucker, or lateral shoot), and a flower or fruit. At the first 5 or 6 nodes counting up from the base of the plant, pinch off the side shoot. [Side shoots are vining branches that grow off the main stem, and will form their own leaves, flowers, fruits, etc.] Also, remove any flowers as they develop on these 5 to 6 lower nodes. Many growers allow just one flower to form on the upper nodes, as well. Depending on the training system, side shoots on the upper nodes are either allowed to grow along a wire or other support, or removed so that there is just one vertical stem.

You can prune the lateral shoots, but do keep the main stem. You may want to do this several times during the growing season.

Female flowers are swollen at the base. This swell is the ovary and a tiny pickle. Note that the early flowers are males so sometimes it's just a question of patience. Both flowers need to be available to bees at the same time without fluky weather interference. Here are pictures of female and male flowers if it helps:
http://vric.ucdavis.edu/pdf/fruitsetproblems.pdf

One crop should produce fruit for about 5 to 6 weeks. The more you pick, the more the vines will produce. Growing vertically increases your yield, too. In terms of the green color of your soil, has it been very wet? Are you using a soluable fertilizer? We'd advise that you add organic matter such as compost and organic mulch to improve your soil.

If you're fertilizing, back off. If you're watering, be sure it's consistent and at the base of the plants, not overhead. Ensure the plants get 6 to 8 hours of sun per day. Otherwise, it's often a pollination issue. You need to plenty of bees which also do not get deterred by fickle weather. You could always hand pollinate. The good news is that cucumbers for pickling should be picked when they are short: 2 to 4 inches long!

There are "vine" cucumbers and bush types. Bush types take up less room and are great for containers. If you have a vine type, you'll need a vertical trellis for the vine to climb--a bamboo trellis would work. In terms of size pot, 1 cucumber needs 1 gallon container. Here's a great source to help you grow your cucumbers and any vegetables in containers: http://aggie-horticulture.tamu.edu/publications/guides/e-545_vegetable_gardening_containers.pdf

Sounds like your plant has powdery mildew.

Try treating with a safe fungicide. To prevent it in the future, try a slow-release fertilizer and make sure they get good sun.

For disease control, avoid picking cucumbers when wet. Also, be sure to water at base of plant and try not to let water splash on leaves. And ensure your plants have good air circulation.

Cucumbers usually need 1 inch of water each week. The usual reasons for yellow cucumbers are: too much watering, nutrient imbalance, or a virus. In terms of bitterness, this can happen in dry weather. Bitterness also due to the way you eat cucumbers. To minimize their "bite," remove the skin and trim both stem and blossom ends. Scooping the seeds and seed membrane from the center also results in milder-tasting cucumbers. European (or English) cucumbers do not need such treatment; they may be served skin and all.

For climbing cucumbers on a trellis, the side shoots form right where the cucumbers form at the joint of the main stem. Keep the plant to one stem by pruning off all the lateral shoots that appear. Be ruthless as it will keep trying to send out lateral shoots everywhere; it's a daily task. Wait until the vine has 7 leaves before you start.
If you a bush variety of cucumber (picking types), you do not need to prune.

It may vary--I'd say flowers form after three weeks. Male blooms are usually first. They may drop off. A week or two later, you'll see female flowers (differentiated by a cucumber-shaped bulb at the base).

Hadn't heard this. You want to let the fruit develop and pick your cucumbers when they're at the right size -- which depends on the variety. For slicing varieties: 6 to 8 inches long. For pickles: they can be no more than 2 inches long. Once they start producing, the fruit grows quickly so expect to harvest every day or every other day.