When considering a sow out of a new grass re seed, there are many factors to consider. Soil health, type of soil and the purpose of the field i.e. grazing and cutting, grazing only, cutting only and how long you want the grass down for.
The above factors are very important to consider as this will determine which grass mixture suits your situation and most importantly will help you on your way to achieve a successful and productive re seed.
Two other crucial factors that you need to consider are sowing method and how to manage the grass once it’s through the ground.
There are a range of sowing methods from a complete plough re seed to a direct drill onto sprayed off ley, with each way treated differently when it comes to a re seed.
A complete plough re seed is the preferred option for many as this tends to happen following crop rotation in an arable situation and following a forage crop. It is very important that the soil health and fertility are assessed beforehand as this will help with the establishment of the grass and make the job a lot easier and more pleasant to the eye once sown.
Once ploughed, preparing the seed bed is vital, whether you are using a power harrow, chain harrows, discs, crumbler land leveller or paddle rollers. A fine, crumbly soil needs to be achieved as this will help the seed settle in evenly and distribute fairly. A well consolidated seed bed is preferred as this locks in moisture and allows good seed to soil contact. Ways this can be achieved are by using the power harrow or leveller after ploughing, then heavy rolled or Cambridge rolled prior to sowing.
Once the grass seed is sown, a heavy roll is imperative as this will ensure seed to soil contact and help with further consolidation of the ground. An application of a balanced fertiliser can be applied if chosen, either pre or post sowing.
A common problem after a complete plough re seed is, the number of weeds and unwanted trash that appear through the grass. Weeds like spear thistle, docks and nettles are increasingly frustrating as these are perennial weeds that ideally need to be eradicated by a spray application. Other weeds like chickweed, fat hen, and day nettle are all annual, so once these are either grazed or mowed down, the likelihood of them re appearing is very low. Another method that is used is “a stale seedbed”. This method is performed once the field has been prepared for sowing, it is then left for any annual weeds or perennial weeds to appear, these are then sprayed off and this then leaves the field ready to sow while minimising soil disturbance. The final method that is growing in popularity is direct drilling onto a sprayed off grass ley. This is often chosen, if the field is prone to be shallow, stoney and difficult to cultivate. There are a range of direct drills on the market, some that are gravity driven, some that are pneumatically driven and some that are broadcast driven. Different methods of seed planting are also available from, slotting the seed straight into the existing ley to aggressively harrowing the seed into the existing ley. Either method is appropriate for whatever situation you have and it is important to remember the principles are the exact same when it comes to re seeding, soil health, fertility, moisture and especially when it comes to direct drilling, a weed and trash free seed surface to plant on. What is very important to remember after a direct drill reseed is, avoid any application of artificial fertiliser until you see the new seedling appear. An application prior to this will only benefit what grass was previously burnt off. The establishment time for any method of grass re seeding is really dependant on how well the field has been sown e.g. the consolidation, the soil health, the application of artificial or organic fertiliser and moisture. Usually, the time frame is about 6-8 weeks before the first light graze or another technique that is used is the “tear test”. This is when you tear the grass with your thumb and fore finger, and if the roots don’t come out then the grass is ready to be grazed. Giving the new re seed a light graze on and off, helps with the tillering of the plants, leaving you with a thick dense sward.
