Core Ideas Canola forage production was higher than wheat in fall but not in later harvests. Many of the forage quality parameters were superior in canola compared with wheat. Forage harvest decreased canola yield even before bolting but not in wheat. Canola has dual‐purpose use potential (forage and seed yield) with LF harvest. Winter canola (Brassica napus L. biennus) has the potential to be a dual‐purpose crop in the US Southern Great Plains, a region with cereal fallow mono‐cropping. However, there is little information on dual‐purpose canola in the region. Therefore, field studies were conducted in Clovis, NM, in 2013, 2014, and 2015 to compare harvesting time effect on forage productivity (dry matter), quality, and oil and seed production of canola and wheat. Harvesting time treatments were late‐fall (LF), mid‐winter (MW), early‐spring (ES), late‐spring (LS), and no‐harvest (NH). The two forage crops were canola (cv. DKW44‐10, Griffin, and Safran) and wheat (cv. TAM 111 and TAM 113). In general, crop dry matter increased and forage nutritive values decreased with delay in harvest. Dry matter of LF to ES harvests ranged from 2950 to 7740 (canola) and from 2390 to 7490 kg ha−1 (wheat), suggesting superior forage production of canola with LF to ES harvests. Crops had similar crude protein and acid detergent fiber. Canola's neutral detergent fiber was lower (238 vs. 425 g kg−1), whereas its relative feed value (188–425) was higher than wheat (127–204). Average canola seed yields (excluding 2014) were 4360, 3040, 2940, and 2720, 930 kg ha−1 with the NH, LF, MW, ES, and LS forage harvests, respectively. Forage harvest had inconsistent effects on wheat seed yield. These results show canola's potential to produce high‐quality forage and seed yield and indicate that canola can be used as a rotational break crop in the crop–livestock production systems of the Southern Great Plains.