When to sow which seeds for seedlings? A Guide for Beginners

“When should you plant seedlings?”, “When is the best time to sow tomatoes and peppers?”, “When do the seedlings go outdoors?” – Every hobby gardener has been asking these questions since January. In this article we explain when to sow which seeds, because properly grown seedlings are the keya good harvest in the vegetable patchor a lush bloom in the garden.

Sow and grow seeds: The vegetation cycle begins on the windowsill

The number of warm days in our latitudes is pitifully small for the full vegetation cycle of any plant species. That's why we start this cycle on the windowsill (by preferring seedlings) instead of planting the seeds directly in the garden soil. If there is insufficient light there, you can use artificial light sources. Plant lights, also called phytolamps, are ideal for this purpose.

The length of the growing season depends on the speed of maturation of the variety.This varies not only between species, but also between varieties. For example, there are specially bred early ripening varieties for cultivation in the conditions of a short northern summer (but those who are impatiently waiting for the first tomatoes will also be delighted).

However, there are still plants that have a very long growing season, such as: B. the Chabaud carnation (Dianthus caryophyllus var. schbaud), the busy lizard (Impatiens walleriana), lobelia (Lobelia), the garden strawberry (Fragaria ananassa) and others. For them, you need to apply additional lighting, which artificially increases the light day to 15-16 hours.

So when should you sow the seeds? And when should the young plants come out? The best time for sowing varies depending on the stage of plant development. It is important to know how many days it takes for the seedlings to emerge, if and when they need to be picked, and the recommended age for planting the seedlings. This information, as well as the total length of the growing season, is generally availableon the seed baglisted – for the respective variety. Everything is clear so far, but what to do if this is your first gardening season? Have you never sown tomatoes before and don't know anything about how long they germinate or sow? For your region, May 15th is early spring, but wouldn't it be too “late” for sowing by then? Try to count the first year strictly according to the calendar.

The average dates for the most popular vegetable crops are as follows:

(germination time / age of seedlings for sowing outdoors)
Cucumber – 2-3 days; 25-30 days;
Tomato – 6-8 days; 45-60 Take;
Paprika – 12-14 Days; 65-75 Take;
Eggplant – 10-12 days; 50-60 Take;
Zucchini – 3-5 days; 25-30 Take;
Pumpkin – 3-5 days; 25-30 days;
Lettuce – 3-5 days; 35-45 days;
Celeriac – 12-18 days; 75-85 days;
Leeks – 12-15 days; 45-55 days;
White cabbage – 4-6 days; 40-50 days.

To determine when to start seedlings, count from the expected date of planting in the ground: 80 days for peppers means sowing seeds in February, 60 for tomatoes = mid-March, 50 for cabbage = late March, and so on.

Being late isn't a problem either

As spring approaches, the daylight hours become longer, meaning the seedlings get more natural light. It has long been observed that tomato and pepper seedlings planted later easily catch up and then overtake the plants sown earlier.

The age of the seedlings is the most important factor for sowing outdoors. And it is better to plant seedlings slightly undergrown than overgrown. Overgrown seedlings are more difficult to transplant, take root much worse and are more susceptible to disease during the adaptation process. This is one of the reasons why the timing of sowing for seedlings should be calculated individually.

What is the climate like in your region?

The timing of when seedlings can be transplanted to a permanent place depends on the climatic conditions in your region. Look for a period of consistently warm temperatures without further frost. It is therefore important for every gardener to know the number of warm days in the month. It is clear that they can change from year to year, but here we can only rely on weather forecasts, the accuracy of which, unfortunately, leaves much to be desired. Therefore, you can initially base your sowing on average values ​​based on long-term meteorological observations.

Where to plant seedlings

There is a difference whether the young plants are planted outdoors, in a plastic tunnel, in a polycarbonate or glass greenhouse. The timing of planting seedlings and sowing seeds in open ground and in the greenhouse usually differs by 30-45 days. The higher the bed is, the sooner it warms up. Planting in raised beds can be done 2-3 weeks earlier than outdoors at ground level. As it turns out, peppers for seedlings in the greenhouse can be planted as early as January.

Outdoor sowing of cold-resistant and slow-germinating crops (radishes, lettuce, carrots, parsley, dill, radish, cabbage, beets) begins when the soil at a depth of 5-10 cm warms up to 8-10 degrees during the day. At the same time, the first seedlings of heat-loving plants such as peppers, tomatoes and cucumbers can be germinated in the greenhouse. Since Germany is largely in the cool temperate zone, that means roughly between May 1st and 10th. For the southern regions, early April to mid-March.

Tomatoes and seedlings of other heat-loving plants should be planted outdoors when the threat of another frost has passed and we have stable warm temperatures. Typically this means June 10th - 15th for northern Germany, the first decade of May for central Germany and the first decade of April for the southern regions.

Tip: Search Google for climate data for your city. Check out the temperatures based on recent years' data.

Sow seeds: Plan by week

Make a list of vegetables and annual flowers you want to plant this year. Immediately note which varieties you will grow, under what conditions, and indicate the expected planting dates. This way you will know exactly when to plant your seedlings.

It is convenient to create a table at the planning stage containing the following information:

• the name of the plant species and variety;
• Planting location – open ground or greenhouse (you can immediately plan the specific planting location and number of plants);
• days for germination of seedlings;
• the age at which the seedlings were planted;
• the best time to sow the seeds;
• The dates for sowing seedlings outdoors can now be easily calculated using the data you have in front of you.

Here is an example:

*This table is intended for mid-latitudes with a moderate climate. If you live in the southern regions, you can start sowing and planting seedlings 5-7 days earlier, but in the northern regions - a week later.

It is also useful to have a separate column with expected fruiting (or flowering time for ornamental plants). This can be calculated knowing the growing season of the respective variety. Sometimes the timing of sowing seeds for seedlings is calculated only based on the time of fruit formation.

The flowering and harvest time is particularly important for annual plants. After all, this is why you grow them. To achieve a longer lifespan, not only varieties with different flowering speeds can be used, but also the timing of sowing seedlings can be varied. By varying the age of the plants, fruiting will occur at different times. This will also help correct the vagaries of the weather.

Don't overdo it either. Remember that it is important to plant the seedlings outdoors on time. Consider your options. How often are you willing to take the time to transplant seedlings? It is more convenient to do this in large quantities for different species and varieties. So it's worth planning a few planting dates that suit the weather conditions and are convenient for you. You can use this to calculate the dates for sowing the seedlings so that they are mature in time for the planned planting dates.

Sowing seeds: Calculate sowing dates

Now you can calculate the sowing dates for seedlings based on the data entered in the table. To do this, subtract the age of the seedlings and the number of days of germination from the planned planting date. If you have to separate seedlings, you should deduct an additional 4-5 days for the young plants to adapt. This will give you a fairly accurate date for sowing your seeds. Given the ambiguity of weather factors and different growing conditions, a fluctuation of about 10 days is quite normal.

It would be optimal if you make your own calendar for sowing and planting seedlings. But in an average form for the cool temperate climate zone, the times will look like this:

February
Sow seeds: II decade of February – celery, chili, wild garlic, basil, oregano, parsley, mint, tarragon
Sow flower seeds: Sweet peas (Lathyrus odoratus), Levkojen (Matthiola), lobelia, bellflower (Campanula)

March
Sowing vegetable seeds: I. March decade – early varieties of tomatoes for growing in a greenhouse, white cabbage, leeks, arugula, rhubarb
II decade of March – late varieties (for growing in open ground) of tomatoes, peppers
III. March decade – early varieties of tomatoes for growing in open ground, eggplants

Sow flower seeds: petunia, busy lilies (Impatiens), marigold (Tagetes), delphiniums, ornamental onions, phlox
Sow herb seeds: watercress, dill

April
Sowing vegetable plants:
I. April decade – cucumbers for growing in the greenhouse, cauliflower, broccoli
III. April decade – zucchini, pumpkin, cucumber for outdoor cultivation, lettuce

Sowing flowers: nasturtiums, zinnias, forget-me-nots, cosmea, marigold (calendula), decorative sunflowers (helianthus, gerbera)
Sow herb seeds: thyme, sage

May
Planting seedlings outdoors or in a greenhouse:
First decade of May – cucumber, tomatoes in the greenhouse;
Second decade of May – leeks, white cabbage, peppers and eggplants in a greenhouse;
III. May decade – cauliflower, cucumber, pumpkin, zucchini, celery, cabbage

June
Planting seedlings outdoors:
I. June decade – The tomato, Paprika

If you take the time to plan and calculate the optimal dates for sowing seeds and planting seedlings in the ground, you can get healthy plants that require less care and give a stable harvest, extend the fruiting period and the Make work in the garden easier and more productive.

Growing cuttings from seeds: Here are a few basic rules you should know

Before you start sowing, you should calculate how many seedlings you need. You can still buy the missing specimens, borrow them from a neighbor, or plant another plant in the vacant space. But if there are too many seedlings, it is always difficult to find a place for them on the plot or in the raised bed. This is primarily due to the psychological inability to throw away a living plant. Don’t make yourself any extra work – less is better. Here are some tips on what else you should pay attention to when sowing seeds.

How many seedlings are needed?

Knowing the size of the greenhouse, bed or flower bed and the minimum distance between plants, you can easily calculate the required number of seedlings. Increase this amount by approximately 30% to account for unforeseen circumstances.

The second criterion for the number of seedlings is the area of ​​​​window sills and other suitable areas available to you for germination. After all, growing it at home requires quite a lot of space.

The right light for seedlings

Growing seedlings at home requires sufficient light. Without it, the seedlings will not develop properly and will grow poorly. Weakened seedlings are susceptible to various diseases. Therefore, one cannot count on a rich harvest or lush flowering.

Normal light bulbs are less suitable for additional lighting for seedlings, but daylight fluorescent lamps (from 5500 K) and grow lamps are. But since the pink-purple glow of the latter is unusual and even harmful to the human eye, they should be used in a set with special mirror reflectors and/or simultaneously with the fluorescent lamps.

The light source should be as close to the plants as possible, especially in the first few days after sowing seeds. Therefore, when installing the lights, take into account the possibility of slightly changing the mounting height.

What should seedlings grow in?

In preparation for the sowing season, also take care of the containers for growing seedlings. These should meet a few important requirements. First, they must have holes in the bottom and a separate tray for draining excess water. Second, choose containers made of a sturdy but lightweight material (wood or plastic) so that they can be transported from one place to another as needed. They also need to be cleaned and disinfected after use; Plastic is more suitable in this case.

The material of the container must have low thermal conductivity so that the roots of the plants do not suffer from the temperature differences.Cardboard or egg carton nursery potsare often used, but some gardeners report mold growth.

Notice: Do not place the boxes with seedlings directly on the windowsill. Choose a surface made of wood or Styrofoam. There are also growing trays on feet on the market.

Potting soil for seedlings

Growing seedlings at home requires sufficiently permeable, loose and moisture-absorbing soil so that when watering, water seeps better and quickly reaches the roots of the seedlings. Most varieties need pH-neutral soil, but some plants (e.g. gentians, ferns and conifers) prefer acidic soil - just like in the field.

You can buy ready-made potting soil from specialist stores or you canMake your own sowing soil. The mixture usually consists of turf and leaf mold (leaf humus) as well as coarse sand. Some gardeners add hydrogel to increase moisture.

The purchased soil does not need to be pretreated. The self-prepared soil mixture should be poured with boiling water or heated with steam to prevent fungal diseases in the seedlings.

Sowing seeds: the right depth

When all preparations are complete, you can start sowing. Here you should strictly adhere to the cultivation technology - it is different for each culture. The seeds of some plants (heliotrope, lobelia, petunia, etc.) germinate only in the light, they are simply distributed on the surface of moistened substrate. Most seeds are placed 1 to 4 cm deep and covered with soil.

Two rules apply to all crops: seeds should be sown in previously moistened soil, and after sowing they should be covered with glass or transparent film so that moisture is retained. As soon as the seedlings appear, the film is gradually removed.

Optimal temperature for seedlings

For each crop there are optimal, minimum and maximum temperatures for germination and subsequent growth. For example, begonias and petunias germinate at + 22-24 ° C, while the optimal temperature for cabbage is + 8-10 ° C. You can find all the necessary information on the Internet or in specialist literature. In any case, after germination you should reduce the temperature by 2-3°C so that the plants can root better and only then continue to grow.

Note that lower temperatures are also desirable at night. This is because photosynthesis and respiration in plants depend on temperature. Because photosynthesis stops at night but plants continue to breathe, the need for high temperatures is lower. Even with little light, the following applies: the less light, the lower the room temperature should be.

How should I water my seedlings?

Watering also directly depends on the amount of light. On a hot, sunny day, sprouts, especially those with large leaves, should be watered in the morning and evening. When there are few daylight hours and in cloudy weather with low air temperatures, 2 to 3 waterings per week are sufficient. Make sure the soil in the container remains moist but does not become waterlogged.

Irrigation should be done with tap water. At the beginning of growth, seedlings and small saplings should be watered with a spray bottle so as not to damage the weak stems and leaves.

Prick out cuttings

Growing plants should be transplanted into individual cups so they don't compete for nutrients and light. With good care and adequate light, most plants are ready to be separated as soon as two to three leaves are present.

Seedlings can be easily transplanted using a table fork or a special pricking fork by removing a few plants from the seed container and carefully pulling apart the roots. You can also shorten the central root with scissors so that the side roots form better. The branched root system allows the plant to absorb nutrients more intensively and over a larger area. This way the root system remains superficial. The plant requires frequent watering because the roots do not penetrate deep into the soil to provide themselves with moisture. Shortening is not recommended for plants with a taproot system.

And this is how pricking works: soil is poured onto the bottom of the individual cup and moistened thoroughly. Holes are now pierced into the substrate with the pricking fork. These should be large and deep enough so that the roots of the seedlings can fit into them without bending them. Now the seedling is placed straight into the hole and covered with soil.

Sometimes the small seedlings are transplanted “bouquet-like”, a few plants in a cup. In this way, the roots are less damaged and the plants acquire a decorative look more quickly.

Transplanting is carried out on a cloudy day and then the seedlings are shaded for a few days. This allows the plants weakened by transplanting to acclimate and begin to grow again.

Harden off seedlings

The cultivation technique involves hardening off the seedlings a few days before transplanting them outdoors - this will acclimate them to outdoor conditions.

Hardening of seedlings is carried out in warm, cloudy, windless weather by placing them outdoors for the first time for 10-15 minutes. Little by little, the time spent outdoors is increased. At the end of the week, if the weather remains consistently warm, the seedlings can be left outside overnight so that they become accustomed to the daily temperature fluctuations. To avoid sunburn, the seed containers should be shaded and protected with covering material at night. Hardening off seedlings prepares them for transplanting.

Transplanting seedlings outdoors

As a rule, heat-loving plants are grown through seedlings, so transplanting them into open ground is only possible when the danger of another frost has passed. The prepared hole is filled with the necessary fertilizers and watered abundantly. When the soil has already dried out a little, the seedlings are carefully removed from the cup and lowered together with the lump of soil into the prepared hole, covered with soil and compacted.

Extra-long tomato seedlings can be planted at an angle and, after cutting off the lower leaves, covered with soil to a greater height than in the tray. Lateral roots then form on the stem below the surface, and the plant itself assumes an upright position after a few days. Other types of plants should preferably be placed at the same depth as in the cup. After transplanting, mulch the soil, shade the seedlings and leave them without watering for a few days to allow the roots to spread and grow in search of moisture.

A few more tips

Of course, if you are not satisfied with the seedlings you have grown, you can also buy ready-made ones. When buying, pay attention to their appearance: the seedlings should be strong, deep green in color and free of external injuries and signs of disease.

Do not forget to mark the seedlings when sowing and transplanting, indicating the type of plant, variety and date of sowing. It is also worth recording this information in your sowing calendar.

When growing seedlings at home, keep them away from cats and other pets. They all like fresh greens and will not miss the opportunity to explore the taste of seedlings. So make sure that you plant the seedlings in a place that is inaccessible to animals.

Some species can be transplanted during flowering, such as wild pansy (Viola tricolor var. hortensis), petunias, marigolds and some others.