Even if we automatically think of spring when we think of fresh green seeds, autumn is an excellent time for planting new or reseeding lawns. Because the many small grass plants have their own requirements for the conditions for “happy growth”, which are usually easier to meet in autumn than in any other season:
Only good seeds bring good success
High-quality seeds are the first point in the “process chain” that have a decisive influence on the success of your sowing project.
To ensure that the right mix of grass plants is in the seed pack, the Landschaftsentwicklung Landschaftsbau Research Society e. V. has been putting together “regular seed mixtures for lawns” (RSM lawns) for a wide range of applications and site conditions since 1978/1979, the use of which guarantees lasting greening success when sowing and caring for the lawn properly.
These RSM lawns are usually sold in simple bags, but the quality differs significantly from some lawn mixtures on the market, which have well-known names, but only offer beautiful green lawns for a very short time. In addition, with these lawn mixtures you will find exactly the lawn you need: ornamental lawn and utility lawn (for dry areas, as play lawn or herb lawn), sports lawn and landscape lawn in a wide variety of variations and many other mixtures if you have a special use in mind for your property. Here: www.fll.de/shop/produktion-guteregulations/regel-saatgut-mischen-rasen-2017.html you can find information and the latest rules, you can buy the rule seed mixtures for lawns in any well-stocked seed shop.
With quality seeds, the seeds of perennial grass plants are adjusted after harvest in such a way that they can and will germinate all year round under conditions that trigger germination; a considerable effort:
- The seeds are harvested when they are optimally ripe
- To prevent premature germination, they are dried to an optimal moisture level
- For seeds of grass plants, the moisture content is 14%, standard for storable seeds
- The Seed Traffic Act also regulates minimum germination capacity (75 to 80% depending on the species)
- The seeds are stored in air-conditioned rooms, 10-15°C, humidity 30%
- The storage conditions are constantly and precisely monitored
- Before delivery, the individual batches are subjected to a germination test
This is how the seeds come to the market and from there to you in hopefully unchanged condition - which brings us to the next point: Nowadays, the beautiful green lawn often fails simply because the lawn seed mixture is bought somewhere. A package of seeds is so terribly unspectacular that it seems almost crazy to worry about “the well-being of this seed” during shipping, for example. B. to think. And yet a single seed is a real little “germ factory”, with complicated “equipment”: seed coat, embryo and nutrient tissue, all made up of many individual parts, everything small to tiny and sensitive. You can recognize a good nursery, among other things, by the fact that seeds have a place on the shelf where they are guaranteed never to grill in the sun or be otherwise unfavorably affected.
Seeds from the right source are germinable for at least two and a maximum of four years (guaranteed, often longer) after purchase. If you do not use the seeds immediately after purchase, you must now store them in such a way that they remain in optimal condition. You don't need an expensive industrial warehouse, but even if you store them for a short time, you should make sure that the germination capacity does not decrease before sowing (or is destroyed, which happens faster than you think with these living mini particles):
- Always store seeds in a dry place
- In a room with the lowest possible humidity
- Packaged in such a way that it never comes into contact with water
- Even small splashes can cause the seeds to swell
- More water can lead to germination, rot and mold growth
- The temperature is rather unimportant, a little frost e.g. B. no problem, just hot steam devices/ovens should stay away
- For longer storage, use plastic bags directly on the seeds to avoid possible condensation formation
- Better to hang in paper or cloth bags on the ceiling of an adjoining room
- Pests that have an appetite for nutritious seeds rarely come there
Tip:
Even with the best storage, the biological plant material does not last indefinitely; Grass seeds that have been stored (or have become moist or exposed to sunlight) should only be tried out when reseeding. If you want to close large gaps, you should also mix the precarious seeds with fresh ones; Large failures are too easy to see on small lawns in front of homes. Especially when sowing near the minimum temperatures, you can easily use up old, otherwise intact seeds because the germination temperature requirements decrease with the age of the seeds (according to the motto: “Either now or never”).
Optimal germination conditions for grass plants
For seeds to germinate after sowing, they must be in contact with the right soil, at the right temperature and with the right level of moisture.
The not particularly demanding grasses germinate on any normal to light, loose garden soil with a medium humus and nutrient content. A garden soil that deserves this name must actually exist. If you were to sow lawn directly on a new building site that has been compacted by construction vehicles, many beautiful herbs would emerge that are specialists in germination on such ruderal soils (and are also called weeds; there is no dense green cover). That's why a layer of topsoil is first applied to the construction site soil; ideally, even the site's own soil was removed before construction, stored at the back of the property and maintained during the construction period (this should always happen according to the relevant regulations, but often remains theory). You don't need a very thick layer of this topsoil because most sweet grasses have shallow roots and do not form main roots or taproots.
The right temperature for germination for grasses begins at an uncomfortable + 5° C. At this minimum temperature, not every seed may germinate, but certainly enough to create a (thin) green lawn. However, at 5 °C this occurs “at some point” because the germination time depends crucially on the temperature. At minimum temperatures it takes time, when it is warmer it happens faster; at around 16 to 23 °C, bluegrass germinates fastest. Since +5°C in autumn tends to be colder, when sowing at such temperatures you always run the risk that a) the seeds will freeze instead of germinating (which could at least bring greenery in spring after mild winters) or worse b) the frost catches the young stalks that have “just crawled out of the egg”, causing their certain death.
In addition to a little warmth, the grass seed needs water to germinate or before germinating, first of all the seed swells through water absorption. This not only increases its volume and creates a little space for the first tender, freshly produced root tissue, but also activates the enzymes that are important for the germination process. Very important, the best germination fails if the seedling immediately starves, which is why it is given to him by “Mother Grass Plant” e.g. B. the enzyme diastase is added, which converts the starch stored in the endosperm into nutritious, tasty foods? Sugar converts.
At the same time, the enzymes have broken down the germination-inhibiting reserve substances so that the seed starts germinating; if continued to provide sufficient moisture, the seed coat will next rupture to allow the radicle to grow through. In return, the cotyledons have developed in the upper part, and the leaves afterwards (to us still tiny needles) are the first “real leaves” with which the young grass plant begins to photosynthesize.
The climate in autumn
The autumn climate in Germany has always been somewhat friendlier than our country's northern position would suggest; cool temperate zone, but largely determined by its position in the transition between western European maritime climate and eastern continental climate. In the northwest, the westerly wind often brings in sea air from the Atlantic that has been warmed up by the warm Gulf Stream, with this “warm northwest” extending from the coast to around the Bay of Cologne. Autumn has always been good for sowing lawns in this large area: warm enough above ground, the ground temperatures even more pleasant because the summer heat is still in the ground.
In spring, the soil still needs quite a long time to warm up, when the air temperatures would already allow sowing. In addition, everyone knows late frosts in spring (in the colder southeast, spring sowing is traditionally only done after the ice saints in mid-May), but hardly anyone can remember “early frosts in autumn”.
Climate warming provides even more arguments for autumn sowing: Since the 1990s, the unstable April weather has turned into warm, sunny and very dry early summer weather; while autumn soil is well moistened by the wet summer months (most rain falls in summer) and is kept moist by lots of showers plus fog.
With the increase in the annual mean temperature (1961-1990: 8.2 °C, 1981-2010: 8.9 °C), the cold southeast of Germany is now approaching a climate in which autumn is perfect for sowing lawns is suitable.
Autumn and lawn seeds: Fits
This means that as long as the soil temperature is sufficient and remains sufficient during the germination period, you can still sow lawns in autumn - even in October and November.
When it comes to creating a completely new lawn, you should, however, determine the soil temperature before sowing and try to estimate how this soil temperature will develop during the germination period of the grass. To do this, you first need data about the germination time, followed by an overview of the average germination time of the most important grass species in normal ornamental and utility lawn mixtures:
- Perennial ryegrass, Lolium perenne: 7 – 15 days
- Comb grass, Cynosurus cristatus: 9 – 18 days
- Timothy grass, Phleum pratense / bertolonii: 8 -17 days
- Panel grasses, Poa ssp.: 14 – 24 days
- Red fescue, Festuca rubra: 10 -18 days
- Sheep fescue, Festuca ovina: 11 – 19 days
- Bentgrass, Agrostis ssp.: 12 – 20 days
This information assumes optimal germination conditions at 16-23 °C; If the soil temperature is lower, germination takes longer.
You can find the current ground temperature at the German Weather Service at www.dwd.de/DE/dienste/bodentemperatur/bodentemperatur.html, a forecast about the weather for the next 14 days is available at www.proplanta.de; For both, you choose the region for which values should be displayed.
The later you want to start, the more critical the sowing will of course be: If you start at a soil temperature of 8-10 °C, you have to expect that most of the grasses will need around a month to germinate. For the next 14 days you will find that there is no significant drop in temperature. But it is difficult to make realistic weather forecasts beyond 14 days, and if the weather in your region tends to be "bitchy", you should probably start at a ground temperature of around 15 °C, with a bit of a safety buffer, so to speak.
Tip:
Many articles on sowing lawns point out that grass seeds are light germinators and should only be spread superficially. That's right, light is necessary, and the seedling also has a harder time when the first tender greens have to make their way through large pieces of stone (grains of soil). On the other hand, lawn seeds are delicacies for birds, and in some residential areas that are planted 'conventionally' (with exotic ornamental plants), the birds are already starving in October because the 'foreign greenery' does not feed them. And the light has to be there, but it doesn't exert any direct stimulus; All in all, this means that you shouldn't "bury" the seeds when sowing them in October/November, but you can rake them in easily. Good soil contact even helps bring water to the seeds; Germination will be accelerated if you work the seeds a few millimeters into the soil.
Water from above comes out of the clouds at this time with a bit of luck. But you can't blindly trust in the autumn weather, grass seeds always need to have moisture around them during germination. If autumn sends one day too long of dry, golden autumn weather, the seedling can die if you don't step in with water from the garden hose. You should also pay attention to the opposite: If a freshly loosened soil is flooded by heavy rain, drainage channels may have to be “punched” with a spade so that the seedlings remain sufficiently supplied with oxygen.
Reseeding and care: Generally unproblematic
If you re-sow at the beginning of October, there should be no problems; Rather, you can expect optimal results without any further work.
There can hardly be any problems if you reseed later; in the worst case, you will have to reseed again in the spring.
When sowing in autumn, the care of the newly sprouted seeds must be carried out a little with an eye on the threat of cold snaps: When the stalks are a few centimeters high, they are mowed for the first time and then usually again as often as possible, only cutting away a little at a time becomes. You can do this as long as the temperatures remain reasonably friendly (around 10 °C). If it is likely that it will be colder soon, you should let the lawn grow for a few days longer if possible and then make the last cut of the year shortly before the predicted frosty weather (exactly at the height of the previous cuts, for new and reseeding a height of at least 5 cm is recommended).
