Among the various vegetables that can be grown in the garden, hot peppers are certainly one of the most fascinating and their cultivation fascinates many growers throughout Italy.
There are hundreds of varieties of chili peppers (hot peppers), with varying degrees of spiciness. How spicy the fruit depends on the content of capsaicin, a chemical compound naturally present in the fruit of the pepper plant. Sweet peppers are those with fruits with a very low content of this substance, while in this article we are dealing with cultivars with a high content of capsaicin. To measure how hot a pepper is, a metric called the Scoville scale is used.
From the point of view of cultivation, chilies are not particularly difficult to grow in the garden and can also be kept in pots, however, they require some precautions in choosing the sowing period. This is because some cultivars are plants of tropical origin and in our climate they only survive during the summer months, to remedy this some enthusiasts delight in indoor cultivation.
Variety: which peppers to grow
Before starting to sow or plant chilies in the garden, we are faced with a very interesting choice: which varieties of chili to grow?
The possibilities are innumerable: there are many pepper cultivars, belonging to 5 distinct species at a botanical level:
- Capsicum annuum (to which most varieties belong)
- Capsicum baccatum (South American chillies, the aji family)
- Capsicum chinense (the species of the hottest peppers in the world, including habanero)
- Capsicum frutescens (peppers with sapling plants, including the famous tabasco)
- Capsicum pubescens (Mexican peppers such as rocoto)
We can choose delicate peppers, with a balanced spiciness and a lot of space for flavor (my favorites are jalapeno and aji Amarillo in this sense), opt for national glories (i.e. Calabrian peppers, such as devil pepper), or compare ourselves with super spicy peppers ( such as Naga Morich, habanero red Savina, Carolina reaper). To find out how hot a pepper is, the score in SHU (Scoville Heat Units) is taken into account, which measures the spiciness based on the capsaicin content as established by the Scoville scale. Before starting to cultivate, I recommend a deepening.
Perennial plants or annual cultivation
Many do not know that the chili pepper plant is perennial, unlike many garden plants which are generally biennial. In Italy, due to the climate that provides for a cold winter, chili is often treated as an annual, so it is sown every year, harvesting and then removing the plant, knowing that it would not withstand the winter.
Those who manage to keep the chili pepper sheltered in the cold months can cultivate it as a perennial, avoiding having to restart every year with sowing and transplanting. But be careful that temperatures below 12 degrees cause suffering to the plant, so in our climate, a cold greenhouse or a non-woven fabric cover is generally not enough to overwinter the plant.
Where to plant chillies
We can decide to grow the peppers in the open field, in the right soil and climate conditions, or opt for cultivation in a pot and even indoors with a grow box. If we choose to put the plant in a container, we have the possibility to choose the soil, with the cultivation inside we also control the climatic conditions to which the plant is subjected.
Climate and soil necessary for field cultivation
Ground. The pepper plant, just like that of pepper, requires draining soil very rich in organic substance, for this reason, it is good to remember to fertilize it generously before planting, using well-ripened compost and manure. Chilli prefers a soil pH value between 5.5 and 7 and does well on a moderately sandy substrate.
Suitable climate. In general, chili plants require excellent sun exposure and mild temperatures, depending on which cultivar you sow there are differences, some varieties tolerate the cold better, for example, the rocoto and the aji Amarillo and others that instead ask hotter, like the super hot Carolina reaper and habanero.
Grow chillies in pots
The cultivation of hot peppers in pots is perfect for those who do not have a vegetable garden and want to keep this plant on the terrace or balcony. It is better to choose a variety of chili that tends to form a small plant so that it can fit well inside the container. In any case, the pot size must be discreet (30 cm in diameter, 30 cm in depth).
The pot must have drainage at the bottom that avoids stagnation of water during irrigation (a layer of expanded clay, for example) and must be kept in a sunny position, the climatic conditions already specified when talking about cultivation in the field apply. The advantage of having a potted plant is that it can be repaired more easily.
In addition to the normal cultivation measures that we will explain below to keep chilies in pots, you must remember to irrigate constantly and also to make periodic fertilization. In fact, the restricted space of the container does not allow to have all the water and nutritional resources that allow the plant to be productive throughout the entire crop cycle.
More details can be found in the article dedicated to the cultivation of hot peppers on the balcony.
Indoor cultivation and growbox
If we want to grow peppers inside a house, with the advantage of controlling every pedoclimatic aspect (therefore temperatures, light, humidity, type of soil) you can build a suitable grow box, which must have the right lighting, a heating system, and an of ventilation. I talked about it better in the article on indoor pepper cultivation, although I admit that I’m not particularly passionate about it because I find it a bit artificial. I would not give up on anything in the world to put my hands in the land of the vegetable garden.
How and when to sow chillies
The important feature to know is that chilies require high temperatures to germinate, around 25 degrees.
Wanting to sow directly in the field would imply waiting for the month of May indicatively (obviously it then depends on the vintage and the geographical area), but the risk is that it is too late for the plant to be able to ripen the fruits before winter, so it is much better to sow in a heated seedbed.
The aim is to give birth to the seedlings between February and March and then transplant them into the field in April or May when they are already formed.
The pepper seed has a rather rigid outer integument, so it is not the easiest to germinate, but it is not a problem anyway, as long as there are the right conditions (heat and humidity).
Three important tips in planting:
If you want to give birth to the chili pepper seeds on your own, I suggest you read the dedicated guide.
Preserve the seeds
A particularly exciting and rather simple thing to do is to preserve the hot pepper seeds from one year to the next. In this way, you can make your cultivation self-sufficient and above all keep the cultivars you like best.
There are enthusiasts who “collect” and exchange pepper seeds of various types. It is also useful to dedicate a specific guide to this topic.
Before transplanting a pepper plant, the soil must be properly prepared, this is very important for our horticultural crop to find the right environment in which to take root. The ideal is to move well in advance, working the garden at least 10 days before the transplant.
Here are the steps I recommend:
- Deep digging, preferably done without turning the clod (thus maintaining the soil layers).
- Fertilization. I “sponsor the use of real, mature manure. A good quantity can be 3-6 kg per square meter, which we can partially replace with the same amount of compost. If you want to use pellets, consider one tenth of the weight (therefore 300-600 grams per meter). It is also worth spreading other enriching substances, for example, lithotamnium. You can learn more about the topic of fertilization by reading the post dedicated to how to fertilize hot peppers.
- Hoeing. The hoe work serves to refine the surface, breaking the clods in the first 5-10 cm. As you do this, the manure spread over the surface is also incorporated into the earth.
- Rake work. With an iron-toothed rake we move on to level the surface.
Transplant the seedlings
Whether you have sown the chilies yourself or bought ready-made seedlings, you arrive at the time of transplantation, which usually takes place in the months of May or April, in any case when we are sure that there will be no cold returns.
I recommend leaving the seedling outdoors still in pots for one or two days, in order to allow it to acclimate. We then move on to planting them in the garden by digging a hole and putting them again in the earthen bread (see explanation on how to transplant garden plants).
A little earthworm humus in the hole facilitates rooting and reduces transplant shock.
The distance to keep between the seedlings depends on the variety chosen, indicatively we can keep 50 cm between one plant and another, planting sixth to be enlarged if it is a question of plants that tend to develop a lot, such as the classic tabasco, or to be tightened for more dwarf varieties, such as prairie fire.
After planting the peppers you need to have them, avoid a lack of water, provide reinforcement of fertilization if necessary, clean the flowerbed, and defend the plants from pathologies and parasites.
The chili pepper plant is quite robust, so it can also be grown without using braces, in some cases, however (for example where there is exposure to the wind), a support rod is useful.
During the whole life of the plant, it is good practice to keep the parcel dedicated to chilies clean of spontaneous herbs. We must not do it in a maniacal way: the pepper is a beautiful vertical shrub that does not fear competition from small herbs, but we must not let an excessive vegetative luxuriance of weeds steal resources from our crop.
A good strategy to save time and effort is to mulch, covering the surface around the plants with a cloth or even better straw.
Irrigation and fertilization
During the crop cycle, chili peppers must not be subjected to dryness. For this it is useful to irrigate when needed, keeping the soil slightly moist. The recommendations are to avoid excess water and not to wet the leaves. During the fruiting phase, the water requirement is greater, as well as when the plants have just been transplanted.
A periodic fertilizer supplement is also welcome, we can sprinkle a few handfuls of pelleted manure or droppings, but also do fertigation with nettle macerate or comfrey macerate.
For the most demanding, there are specific fertilizers for hot peppers, but I recommend checking that they are products allowed in organic farming, avoiding the use of chemicals in the garden.
Prune the chillies
During the perennial cultivation of chilies, it is useful to make pruning cuts, which can adjust the plant and keep it tidy and productive, it is not a demanding job, generally, it involves some simple cutting and possible trimming of the branches. It is best to do this in winter or early spring. Talking about pruning in the abstract is never easy because they are operations that should be evaluated plant by plant, and how much to cut also depends on the variety.
The objectives in pruning are first of all to clean up (removal of sick, dry, or damaged branches from the cold) and to select a little to guarantee the plant lighting and air circulation between the branches (eliminating, in particular, the branches under the first node of bifurcation).
Biological defense against diseases
During cultivation, it is also important to defend the peppers from the problems that can occur due to pathogens. Among the diseases, the peppers are subject in particular to problems of a fungal nature, which manifest themselves with brownish patches on the leaves, necrosis, and rot.
Among the most frequent problems, we mention fusarium, verticillium, Alternaria, and downy mildew.
Without detailing disease by disease, it is important to recognize when the pepper plant is sick and to intervene in time by removing the affected parts and possibly treating with cupric products (allowed in organic farming). In addition to these, we also mention powdery mildew, recognizable because it shows a dusty white patina on the leaves, to be contrasted with treatments based on potassium bicarbonate, in more serious cases sulfur.
To defend the peppers from diseases under organic cultivation, the most important thing is prevention:
- Carry out crop rotation, avoiding growing peppers for several years in a row on the same land. Better not to follow other solanaceae with peppers (potatoes, tomatoes, aubergines).
- Work the soil well, ensuring rainwater and irrigation drainage.
- Do not overdo it with fertilizations, which weaken the plant tissues.
- Do not over-water, creating excessive moisture and stagnation in the soil.
- Prune as needed, to maintain an illuminated and airy canopy with some thinning where necessary.
- Periodically distribute horsetail macerates or treatments with propolis, which have a strengthening effect.
In addition to diseases, there are also problems due to an adverse climate or a lack of nutrients, which are not dependent on pathogens. Here are the most common chili pepper pathologies:
- Scalding of the fruit. A strong sun during the summer can burn the fruit, causing blackening of the skin. We can avoid the problem with shading nets or by spraying protective rock powders.
- Leaf yellowing. It can be due to deficiencies in a specific microelement or to an abnormal pH value of the soil. I recommend measuring the pH first, then fertilizing with a quick-to-absorb fertilizer.
- Drop some flowers. When the flowers fall without fruiting it is a big problem, if it is not solved you will lose the harvest. The cause may be in imbalances of nutrients, too much heat, lack of water or late frosts, usually at night.
The most frequent parasitic insects that we can meet when growing chilies are:
The collection of chillies
Understanding when to pick a chili is simple: we can rely on the color of the peel which must all be in a uniform color. If we cut a slightly unripe chili in half, we can see a greenish color in the placenta (the inner part that connects the seeds).
The ripening time varies according to the variety, generally, capsicum annum are the peppers with the shortest cycle, while the exotic varieties are often slower. In any case, from the setting of the flower to the complete ripening of the fruit, the plant can take at least a month, for many cultivars 45 days.
Use of chillies
Some pepper cultivars are very productive and when it comes to harvest you find yourself with a quantity of chili that is above your immediate cooking needs. Here are some ideas for storage and use: