Grandslam F1


Grandslam has become one of the market leaders, being highly favoured for winter harvest where the holding ability and excellent cold tolerance permit harvesting over a prolonged period. Grandslam is a medium maturing hybrid, taking around 90 – 110 days from transplanting to harvest. Plants are large and vigorous with an upright growth habit. Wrapper leaves cover the heads very well. Heads are uniform, large and very firm. Holding ability after maturity is excellent through the over-wintering season. Head shape is round and slightly flattened around the base of the plant at full maturity. Grandslam has intermediate resistance to Fusarium yellows (Foc) and is unlikely to suffer from Tip burn under conditions normally conducive to this disorder. Grandslam is used to produce large heads for individual head sales to hawkers and is also used for bagging – depending on what the market requires. This variety is known for its exceptional taste – making it a favourite amongst consumers.



  • Harvesting should be completed by September to avoid bolting
  • Grandslam is suited to January and February sowings in the Highveld. In the South Western Cape, excellent yields can be obtained with summer sowings
  • December sowings should be restricted to areas where late summer Black rot is unlikely to occur
  • Contact area representative for a sowing guide – very important for this variety