Summarize the following:
Dragon fruits, unlike many other fruits, do not ripen as much after harvest and as a result should be harvested when they are almost fully ripe.  Once the color of the fruit has changed from green to yellow or red, then it is ready to harvest. The small leaves on the sides of the fruit (also known as the “wings”) will also start to fade or turn brown as the fruit ripens. You can also determine the ripeness by counting the days after the plant flowers. Typically the fruit is ripe a minimum of 27 to 33 days after the plant flowers. Proper time of harvesting is four days after the color of the fruit changes. For export purpose, however, it is important to harvest slightly sooner, a day after the color changes. You can remove the thorns by using pliers, brushing them off, or with gloves. When the fruit is ripe the needles should begin to shed anyways, and as a result they should not be too difficult to remove. However, you should always wear gloves and be cautious because the needles are very sharp. When a dragon fruit is ripe and ready to be harvested, it will detach from the plant easily by twisting a few times. If you have to pull too hard on the fruit then it is likely not ready to be harvested. Do not wait until the dragon fruit has fallen off the plant. This means that the fruit is overripe.

Summary:
Harvest dragon fruits when they are close to fully ripe. Remove the thorns from the fruit before picking. Detach the dragon fruit from the vine by twisting.