How to Properly Grow Seedlings? Guide to Equipment for the Spring Season

Spring is approaching, and it is time to start preparing for the upcoming growing season. If you want to get ahead of the weather, raise seedlings at home and your plants will reward you with rapid growth, strong health and an early harvest. What will you need, and how do you do it? We have prepared a clear guide to raising seedlings for you.

Why raise seedlings?

Raising seedlings indoors in the comfort of your home is an excellent way to get ahead of the start of the season. Avoid the risks associated with unpredictable spring weather, and your plants will quickly adapt to outdoor conditions after transplanting. Another advantage is that, thanks to raising seedlings, you can also grow plant species that would otherwise not thrive in our climatic conditions.

• Ideal conditions: Germination and raising seedlings indoors allows you to create an optimal environment for plants.
• Faster growth and earlier harvest: Plants spend the first weeks of their lives in a protected environment, where they can strengthen and develop a rich root system. Once planted outdoors, they then grow faster and ripen earlier than with direct outdoor sowing.
• Ability to grow different species: Many plants take too long to grow and ripen to mature in our geographical conditions. However, if you raise these species before the start of spring, you can shorten this period.

Which plants are suitable for raising?

Not all plant species need to be raised first, and some, such as radishes, peas or carrots, are sown directly into the bed because they do not tolerate transplanting or they grow quickly and ripen very early. The most common crops that are raised include:

• Fruit vegetables: tomatoes, peppers, aubergines, chilli
• Medicinal and exotic species: hemp
• Cucurbit vegetables: cucumbers, courgettes, pumpkins
• Leafy vegetables and brassicas: lettuces, broccoli, cauliflower, cabbage
• Aromatic herbs: basil, marjoram, thyme, rosemary
• Ornamental flowers: marigold, petunia, snapdragon, lobelia

What will you need to raise seedlings at home?

Although it is possible to raise seedlings on a windowsill or in a conservatory, you will achieve the best results in a grow tent (growbox), where you can create a protected and stable environment for the plants. Inside a grow tent, you can easily control temperature, humidity and the amount of light, and the plants can germinate and grow without the influence of weather fluctuations. Seedlings in a stable environment grow faster and are more resistant to pests, mould and disease. In addition to a growbox, for raising seedlings you will also need:

• Propagator: Miniature greenhouses will help you create the ideal climate for germinating seeds and young plants. For growing some species, propagators with heating are suitable.
• Seedling tablets, cubes or cylinders: Seedling cubes make germination and handling seedlings easier. They can be made from various materials, such as rockwool, coco or peat. Remember that seedling cubes are intended for germination, and after a few days it will be necessary to transplant the plants into a suitable growing medium.
• Growing medium: The choice of growing medium for seedlings depends on the species and the growing method. It is important that the medium is airy and does not contain a high amount of fertilisers that could burn young plants. You can read about the advantages and disadvantages of different growing media here.
• Grow lighting: For rapid growth, plants need enough light. For raising seedlings, the most suitable option is energy-efficient LED grow panels with a growth spectrum.
• Heating mat: Some species germinate and grow better at higher temperatures. Heating mats are especially suitable when growing heat-loving species, such as tomatoes or chilli.
• Sprayer: Watering young plants by hand can easily wash them out of the medium, so we recommend adding a hand sprayer to your basket.

Unsure which equipment to choose for raising seedlings? We have prepared complete seedling-raising sets for you, containing everything you need to get the outdoor season started.

How to raise seedlings – step-by-step instructions

1. Seed selection and preparation

• Use only quality seeds with high germination rates.
• It is advisable to soak the seeds of some species (tomatoes, peppers) in lukewarm water for several hours before sowing.
• To increase the success rate of germination for rare or old seeds, use a germination stimulant.

2. Sowing and first watering

• Sow the seeds into seed-starting medium or into a seedling tablet, cube or cylinder.
• Cover them with a thin layer of medium and gently moisten with a sprayer.
• Place the seeds in a warm, well-lit place (20–25 °C).

3. Ideal conditions

• Temperature: Seeds of most plants germinate best at a temperature of 20–25 °C.
• Light: Provide at least 12–16 hours of light per day.
• Humidity: Keep the medium moist, but not waterlogged.
• Ventilation: Ventilate the propagator regularly to prevent mould growth.

4. Transplanting and hardening off

• As soon as the seedlings produce their first true leaves, transplant them into larger pots.
• Water the seedlings regularly and you can use a weak growth fertiliser.
• Before planting them out in their final outdoor position, harden the plants off. First leave them outside for a few hours a day, then for the whole day later on.

Looking for more growing tips and expert gardening advice? Take a look at our Higarden blog, where you will find recommendations and guides for beginners and advanced growers alike.