This is how you get difficult seeds to germinate.

Some seeds may be more difficult to germinate than others. Some may need to be cooled for a period, soaked or even lightly filed with a nail file before they sprout. Here are the tips you need to succeed with even the most stubborn seeds.
This is how you get difficult seeds to germinate.
This is how you get difficult seeds to germinate.
Liselotte Roll
Written by: Liselotte Roll

Swedish garden inspirer, journalist and author of books about nature, cultivation and animals, such as "Soil", "Grow for insects" and "Chickens as a hobby".

Have you ever planted a whole bag of seeds that just refuse to grow? Many of us have been there, and there could be several reasons why.

Seeds that require cold

Maybe it is because the seeds need one or more periods of cold to get started. Some seeds actually need cold, darkness, and moisture to germinate, a process called stratification. This usually applies to plants that normally live in cold places, such as many tree-like perennials, shrubs, and trees. The seeds have evolved this unique trait to survive the winters. If they had started to sprout in late summer or fall in their wild habitat, the tender and fragile plants would freeze to death during the winter. Therefore, the seed is wise to go dormant until spring arrives.

One way to succeed with seeds that need a cold period is to sow them outdoors in winter and cover the seeds with snow - or even easier, let the plants sow themselves. Another option is to collect the seeds in February/March, after they have already been stratified outdoors.If you prefer to sow indoors, you can use the refrigerator. You can either place the pots with newly sown seeds in the refrigerator for a while, or you can put the seeds in the refrigerator before sowing. If you choose the latter, it often works well to place the seeds in a box with sand, white moss, or vermiculite. Once you see the seeds starting to sprout, take them out and sow them in soil so that the germination process does not stop.

Do not give up if the seeds refuse to sprout after one treatment. Try again! Some seed types, such as Queen Anne's lace and giant verbena, may need several rounds of cold and warm temperatures before they germinate.

Seeds that need to be soaked or ground

Seeds with hard shells can sometimes have difficulty germinating, as the shell prevents moisture from penetrating. By soaking the seeds before planting them, they usually germinate more easily. Place the seeds in lukewarm water for a day, unless otherwise stated on the seed packet. The most important thing is that they swell a little. Chili, peas, and beans are examples of seeds that benefit from being soaked. Some seeds with thick shells may benefit from being scarified before planting. This can be done by gently filing with fine sandpaper or a nail file. Some seeds require both soaking and scarification.

Seeds that grow in the darkness

A few seeds are not satisfied with just being covered with a little soil, they want it completely dark before they germinate. In these cases, you can place a cover or a bit of black plastic with tiny air holes over the newly sown seeds. Check them every day, because when they start to sprout, the opposite applies - then they need fresh plants light!

Seeds that need a lot of light

Some plants only sprout if the seeds receive plenty of light. These are sown on the surface of the soil and covered only with a thin layer of perlite or similar, which allows light to pass through. Plant lighting is often necessary to speed up the growth of these seeds, and the light should be on for 12-14 hours per day. To prevent them from drying out, it may be wise to cover the newly sown seeds with plastic with air holes, or keep them in a mini greenhouse.

Temperature and bottom heat

Various seeds prefer different temperatures. To succeed with seeds that require extra warmth, such as chili, it may be worth investing in a special heating mat for cultivation. The heating mat helps to increase the bottom heat. Just remember to keep an eye on the seeds you have sown, so they don't dry out.

All seeds need moisture

All seeds that have started to sprout need moisture. To control the humidity, it is wise to put the newly sown seeds in a greenhouse or under transparent plastic with holes in it. Check the moisture level daily. Tender new plants that dry out will die. But it should not be too wet either, as the plants may suffer from lack of oxygen.
Sometimes there may be things in the soil that you definitely do not want there, for example pests like fungus gnats. For the most sensitive seeds, it may be worth sterilizing the soil. This is easiest done in an oven or microwave. In a regular oven, the soil should be kept at 100 degrees for half an hour. In the microwave, it takes less time, around 4 minutes. To preserve the moisture in the soil, you should place a plastic cover with holes over it when heating up the soil.

Which soil should I plant in?

As long as it doesn't say anything else on the seed packet, seed soil is usually the best choice. Regular soil can be too rich in nutrients for young plants. But there are exceptions - some seeds can be planted directly in planting soil.

You need help? Ask me!