Chili Plant Temperatures
Several temperatures are important for chillies. For example, there is a night and day temperature. Whether seeds are germinating or the plant is in the growth phase. In addition, there is a corresponding earth temperature.
The simplest way to answer the question of an optimal germination temperature is to use a temperature sensor. It is between 22 °C and 26 °C for all Capsicum species. If your greenhouse is adjusted accordingly, more chili seeds will germinate than at temperatures below 20 °C. They also germinate much faster.
In some tests with different degrees we came to the following result: At 18 °C only half of the seedlings germinated after three weeks. At 22 °C we achieved the same result after only nine days. Overall, the germination rate after 20 days was about 75%. In the case of seeds that are not so difficult to obtain, this is completely sufficient for us. Instead of the usual 10 seeds, we prefer to plant twice as much and sort out sickly seedlings early.
Experience has shown that some plants simply do not want to grow. Don’t be too sad if you have to sort out one or the other plant. On the other hand, the chili growers sometimes have the miserable ones growing on their hearts. The grower is particularly pleased when such a plant produces a handful of pods after two years. Also, among chili growers there are especially social people.
Naturally, however, a higher harvest can only be harvested from strong chili plants. But already during germination a difference between the different species can be seen.
Those who study the climate in the natural environment of Chilis have a clear advantage over other gardeners. This is true for Habaneros, Paprika as well as Rocotos.
The demand for warmth can hardly be more different from Habaneros and Rocotos. Habanero grows wild in the Caribbean and Amazon basin. Here, temperatures of 30 °C per day are normal. At night rarely below 19 °C. At this point we want to mention a high humidity of about 70 %.
It looks different in the home of the Rocoto. The day temperatures seldom climb above 15° during the day and drop to about 8° at night. Many confirmed breeders of the Capsicum pubescens point out that the hairy plants need a clear temperature gradient to feel comfortable.
Capsicum annuum and frutescens like it warm, but the requirements within the species cannot be interpreted so precisely. In the original distribution area in Mexico there are different climatic conditions. From tropical forests to steppe-like regions. Just think of Lipstick or Tabasco Chilis in contrast to Prairie Fire.
The closer you can bring your plants to the local climate, the more comfortable your protege will feel. They will then usually thank you with a full harvest.
If you want to arouse the minds of hotheads, ask about the minimum temperatures for chili plants. One will fervently say 0 degrees, the other will throw a 15 degrees Celsius into the round and the grower with the sharpest chili will hardly let himself be pressed below 20 degrees. The funny thing is, they are all right.
For Capsicum annuum there is a threshold of 16 °C at which the chilli slowly stops growing. A constantly warm environment with around 26 °C is ideal. A stable soil temperature of 20 °C plus minus 2° seems to have the best effect on growth. Permanent temperatures below and above ground of 6 °C inevitably lead to cold damage. Flowers and leaves then fall off. The requirements of Capsicum frutescens are very similar to those of annuum.
Capsicum pubescens germinate reliably at 20 °C and then need 20–28 days to grow their fresh green out of the soil. It is the only Chili species that can tolerate light frost. Some publications speak of - 5 °C. According to our own experience, the lower end of the flagpole has been reached at - 0.8 °C. This is the temperature at which the chili is most likely to be found. If you have precise information, please let us know in the comments. We will then be happy to change the paragraph.
Capsicum baccatum lies somewhere between annuum and pubescens. This is no wonder, since the chilli has its roots in the area of today’s Peru. The “berry-like” plants come from a region where temperatures between 20° and 30° are common. Here there are several strong influences on temperature and climate. Essentially it is the gigantically high mountains and the Pacific with its currents. In some Peruvian regions the weather hardly fluctuates. Constant 20 °C is completely normal. Is Rarely the weather cooler than 15 °C.
The Capsicum chinense still loves the warmth high two. In the area around the city of Cayenne day temperatures of 30 °C are normal. However, over 33 °C which would have a negative influence on the pollination. At night, it rarely gets colder than 23 degrees Celsius.
Have you ever noticed that at high night temperatures the flowers are small? Conversely, the lower they are, the bigger the chili flowers. Below 14 °C there are problems with pollination. The female reproductive organs of the flower inside cannot open well if it is too cool.
As a plant lover, get an idea of the natural environment of your plant. This is the only way to simulate optimal conditions in your home climate zone. In our latitudes, chillies should not be planted outside before 15 May due to night frosts.
A temperature of 20 °C and more is ok for all chillies in the apartment. Rocotos are allowed in cooler rooms. Make sure that the air does not get too dry. In our own article we have already discussed an optimal humidity for chillies.
In summer, a south-facing house wall is a good location in the open country and garden. The wall stores the heat rays of the sun. At night it is warmer here.
A greenhouse is also a good place to grow chillies. But here you have to take care that it doesn’t get too hot. In the hot summer months it is best to shade 10% of the greenhouse.
From about 32° C you have to expect about 10 % smaller chilli peppers. It will be time to ventilate from 38 °C at the latest. It is usually too late to grow more than fifty chilies.