In the summer time, you should grow Cucumber plant because they are grow really fast and only need a few months of growing time. Cucumber plant matures faster and produces delicious cucumber. The only downside is that they are very sensitive to cold weather and frost. They are highly susceptible to insects and other fungus which can easily destroy the whole plant if proper care were not taken in time. When winter comes, the cucumber plants dies off quick and cannot be planted indoors. They need good sunlight to survive.
Chilli plant is good to grow all year round. Chilli plant produces lots of chillies during the summer and they grow pretty fast. Unlike Cucumber plant, they don't require insects to pollinate their flowers to produce chillies. Also during the winter, you can bring the chilli plant into your house indoors and they won't die off. They will only stop producing new chillies or new leaves. The old leaves stays green and some of the leaves do not fall off the stem. Just remember to water your chilli plant once every week and give them fertilizers once a month. Then in the summer time, take your chilli plant outdoors and it will grow back to its original glory. Grow chilli plants in a containers pot because you wanna take them indoors during the winter.