Every gardener or gardener dreams of fast and healthy sprouting of the plants he grows. In order for all the seeds to sprout together and in time, it is necessary to "deceive" them a little: to create conditions for the seeds that will imitate the natural ones.
What is seed stratification
The process of simulating natural winter conditions for seeds in order to speed up their germination and improve germination is called stratification.
Stratification should take 3 weeks or more. For this reason, it is necessary to purchase seeds in advance. On the seed packages, the timing of stratification is indicated.
Under natural conditions, the seeds of plants are for a long time under the snow, where they have embryonic sleep. When the seed enters the warm soil, it "wakes up" and sprouts much earlier. Without stratification, a large percentage of seeds die. If you are sowing seeds before winter, then nature will do all the work and you will not have to work yourself.
Stratification temperature
The most optimal temperature for seeds is 3-5 degrees. But it all depends on which plant the seeds are subject to stratification.
The timing of stratification
The most interesting thing is that the timing of stratification does not depend on the size of the seed. For example, grape seeds should be cold for 4 months and walnuts less than 3 months. The shortest period of stratification is in such plants as: carrots, celery, parsley and onions. It is from 2 to 3 weeks.
Seeds of many flowers show the best germination after stratification: clematis, peony, violet, iris, lavender (should be kept in the cold for up to 4 months). Seeds of primrose, Chinese rose and delphinium stratify within 3 weeks. The seeds of fruit trees have different periods of stratification: apricot (4-5 months), cherry plum (3-5 months), cherry (5-6 months), peach (at least 4 months). At the same time, only one or two months is enough for lilac and bird cherry seeds.
Seed stratification methods
Stratification can be done in different ways: cold, heat, combined and stepwise.
To choose the right method of stratification, you need to know some points:
- For perennials that grow in temperate climates, the cold method is preferable;
- The heat method is better suited for vegetable crops;
- For seeds with a very dense shell, it is better to apply a combined stratification.
- The most difficult way to stratify is stepwise. It is usually used for such plants as: aconite, primrose, some types of peonies.
The method of cold stratification is to keep the seeds at a temperature of no more than 4-6 degrees. Air humidity should be 60-70 percent. If in this way the seeds of sea buckthorn or honeysuckle are stratified, then the seedlings will be friendly and healthier.
The heat method is soaking the seeds in warm water or keeping them in a humid environment for several days.
With the combined method of stratification, the plants are created such conditions that they resemble the changing of the seasons. At first, the seeds are kept in a room with an air temperature of at least 25 degrees. This softens their hard skin. Then they lie for a long time in a cold place with a temperature of 1 to 5 degrees. This method works well for plums, apricots, hawthorns and other dense-skinned plants. The combined method is lengthy and requires some effort from the gardener. But, it fully justifies the time and effort spent.
The tricky way is step stratification. Unlike the combined method, here it is necessary to alternately change the temperature regime: then high, then low.
Stratification is either dry or wet.
Dry method: the seeds are washed with a solution of potassium permanganate to disinfect them. Then rinsed in clean water. After these procedures, it is necessary to dry the seeds and put them either in a plastic bag or in a plastic container. The second storage option is convenient. In the container, you can bury the seeds in the snow so as not to take up space in the refrigerator. And only with the onset of heat, return it to the refrigerator.
Wet stratification can be done in two ways: (1) using sand, moss, sawdust, peat, or (2) cloth.
- Rinse the seeds with a manganese solution, and then running water, dry and put in containers with natural material that has been treated with biofungicide. From above, the seeds are covered with the same material. If the containers are going to be stored in the refrigerator, then you can put them in plastic bags. From time to time, it is necessary to moisten the seeds.
- Cotton or moss is laid on fabric strips, seeds are placed on top of this material. The strips are then rolled up and tied. Each roll must be immersed in water for a while so that the moisture soaks through it. Squeeze the roll and place in a plastic bag. Keep refrigerated. Check seeds regularly for moisture and mold.
Stratification of seeds of various crops
Pome crops - apple, pear, quince: seeds are stratified in wet sand for 3 months at a temperature of 3-4 degrees.
Strawberries and strawberries: there is no need for long-term stratification, it is enough to put the seeds on a damp napkin, cover them with another napkin on top. Then roll everything up and place in a bag. Keep the seeds in a warm place for 1-2 days.
Conifers - thuja, pine, spruce: it is best to place the seeds in moist peat. Place the container with seeds in the refrigerator and keep it there until sowing.
Grapes: grape seeds must be washed with a solution of potassium permanganate and mixed with washed sand. Put the whole mixture in a container in a not very thick layer. Store them at a temperature of 1-5 degrees for a month. Then germinate the seeds at 20 degrees for 6 days. Sow cracked seeds without delay.
Walnut: put the nuts in wet sand and keep them there for at least 3 months at a temperature of 3-5 degrees. If the shell of the nuts is thin, then we reduce the period to one month, and the temperature should be increased to 10-15 degrees.
Cedar: pine nuts have a fairly hard shell and for this reason they germinate better after stratification. Like other seeds, they should be soaked for a couple of days in a solution of potassium permanganate. In addition, empty nuts, when hushed in water, will float up and can be thrown away. Then the nuts are mixed with wet sand (1: 2), placed in plastic bags or plastic containers. It is necessary to store pine nuts at a temperature not exceeding 1 degree for 4 months. The air humidity must be high enough. It is possible to extend the stratification up to 6 months.
Rose: Roses can be propagated not only by cuttings, but also by seeds. First you need to rinse the seeds with hydrogen peroxide.This can be done using a fine sieve, into which seeds should be poured. Moisten paper napkins or towels with the same solution and put the washed seeds on them. Then you need to roll everything up and put it in a plastic bag. Rose seeds are stratified at a temperature of 5-7 degrees for 2 months. Ventilate the seeds from time to time to prevent mold growth. You also need to moisten the napkins that contain the seeds.
Lavender seeds rise much better when stratified. This plant has very small seeds. They must be carefully laid out on damp cotton wool and covered with other pieces of moistened material on top. Then you should put the seeds in a bag. It is better to take a plastic bag for freezing food: such bags have zippers that are very convenient to close. The temperature in the refrigerator should be 5 degrees. Duration of lavender stratification is up to 2 months.
While stratification seems like a time-consuming process, it's worth it. Time and effort spent on stratification will not be wasted.
