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A chilli and pepper guide for spring
Spring is coming in a few months, and it is not too early to start prepping for the coming summer half-year in the greenhouse. Chilli and pepper are great for spring, as the strongest chillies should be sown in January/February. Mild peppers and chillies can be sown later in March.
The guide for chilli and pepper are the same.
An early start for chilli and pepper
The germination process, of the strongest chilli seeds, start late January or early February. The milder sorts can wait a little longer. If you choose to start the germination process early, you need more light for your plants. There are several types of LED lights for plants that are available online. Chilli and pepper can be planted in a seed tray, either together or separately. Always use soil adapted for sprouting seeds. In Denmark it is called ‘Så og Priklemuld’, in Germany ‘Anzucht & Kräutererde’ and in the UK ‘sow and potting soil’.
Avoid the common 3 beginner mistakes
In our online seed shop Spirekassen.dk, we often come across a few beginner mistakes when planting the seed. It is therefore a good idea to read the following three points.
Filling the seed tray – beginner mistake 1
A mistake is filling the seed tray with too much soil. Beginners often pour a lot of soil into the seed tray and press it down, or sometimes even stick their fingers into the soil to make a hole for the seed. Soil MUST NEVER be packed or pressed down. It reduces the oxygen, and the seed needs oxygen during the sprouting process and for the development of the root. Lightly pour the soil in to the tray and then hit the edge of the tray, so the soil naturally finds its way deeper into the tray.
The seed is planted too deep – beginner mistake 2
If you make a hole in the soil for your seed, you are 110 % guaranteed to make the hole too deep. A seed must only be covered with three times the soil, as the seed is wide. A pepper/chilli seed is only a few millimetres big and must only be covered with 6 millimetres of soil. Seeds that are planted much deeper, sprout very late or not at all.
A slow sprouting process – beginner mistake 3
A slow sprouting process is often because of soil that is too hard or seeds that are planted too deep. The next element is temperature. The sprouting process is enzyme dependent, and the efficiency of the enzymes is depending on the temperature. If you chit chilli or pepper at 15 degrees, you will prolong the sprouting process. At 25 degrees it is much faster. The best is for the temperature to be even, day and night, and it is best at 25 degrees.
How to
- Fill up your seed tray with the sow and potting soil.
- Make the soil damp and make a little hole for the seed.
- It is important that the hole isn’t deeper than three times the size of the seed.
- Put a lid on the seed tray.
- Place the seed tray in a warm and bright spot.
- Remember, a chilli seed can take from two to five weeks to sprout.
- Seed and soil must be kept damp during the entire sprouting process.
The little plants
When the first seed leaves are starting to show, the lid should be taken off. It is important that the plants get as much sunlight as possible. The temperature on the windowsill should not be higher than 20 degrees.
After a few weeks, the little chilli and pepper plants get 2-4 sets of leaves. It is now time to replant the plants into bigger pots, with a diameter of at least 10 cm. Approx. 6 weeks after replanting, start fertilizing with a liquid fertilizer. Add fertilizer a few times a week in the irrigation water.
Outdoor life
Keep your chilli and pepper plants inside, on your windowsill until mid-March. In the UK and in Germany, the plants can be planted outside a few weeks earlier. Slowly accustom the plants to outdoor life over a weeks’ time.
Cultivation containers
A good advice is to grow your chilli in pots and jars in the greenhouse. The cultivation containers should at least contain 10 litres of soil. It is wise to grow in movable containers. Chilli is often attacked by aphid during summer. If you don’t want your plants to infect other plants with aphid, it will be easy to take the pot, with the chilli or pepper, outside of the greenhouse, if the problem arises.
Harvest and strength
Usually, the first chilli fruits will be ready to harvest in the beginning of august. Some sorts can be harvested earlier.
Fun to know
The spiciness of chillies is measured in Scoville units on a scale from 0 to 10 (some are also stronger than that). The spiciness is harmless to the body, although it often doesn’t feel that way. The spiciness is not a flavour, but a pain caused by the capsaicin in the fruit. You can train yourself and your body to eat stronger and stronger chillies. That is the reason why some can eat stronger chillies than others. All chilli fruits are mildest in the tip of the fruit. If you are a little cautious, start by eating a piece of the fruits tip. The real spice is in the seeds: approx. 90 % of the power is in the seeds. Slowly taste your way to your limit. Use rubber gloves when handling and cutting the strongest chillies.
Have fun with your peppers and chillies!
Spirekassen.

Om Spirekassen
Christine Wiemann is a greenhouse grower and an agricultural technician and owner of the seed company Spirekassen. Christine is an author of several books about lifestyle, garden life and plant cultivation. Today she writes blogs and shares her knowledge and passion for greenhouses. Christine is a greenhouse expert and an ambassador for Juliana Drivhuse.
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