Fast, and relatively cheap, undersowing lets you re-seed thin pastures without losing much feed in the process. But it can also be a waste of money if it’s not timed right.

 

The single most important step to success with undersowing is getting your new seed into the ground before weeds have colonised bare patches of soil. In open pastures it’s a race between you and the weeds in your soil.

 

Weeds will take hold faster than many people realise; you may only have 3-4 weeks to beat them. After that, the gains from undersowing are usually much less, and you may be best to look at other options.

 

The diagram below illustrates just how quickly the situation can change, as the balance of plant species in a damaged paddock tips from sown ryegrass and clover to weeds. 

 

• For best results: undersow after hard grazing; use treated seed and sow at 50-75% of the normal rate (using more seed in thinner pastures). Graze normally, to prevent seedlings from being shaded.

 

Fast establishing pasture cultivars like Forge or Shogun hybrid ryegrass are ideal for undersowing, because they rocket out of the ground, produce a big bulk of high quality feed and are ready for grazing before winter.

 

The only way they can achieve this performance for you, however, is if it has room to grow! For it to reach its potential, which is significant, it must be sown before existing weed seeds in the soil germinate and get a head start.

 

Forge hybrid ryegrass will last 3-5 years; Shogun will last 2-3 years.