Leaf area index and light interception are essential for yield formation of sugar beet. Due to the slow leaf formation during early growth light interception of sugar beet is rather low in spring and early summer while radiation is already intensive. If it is possible to reach a high leaf area index earlier, sugar yield may increase because of higher light interception. This study aimed at determining to what extend sowing of sugar beet in autumn can improve light interception compared to spring-sown beet. For that purpose field trials were conducted in 2005/06 and 2006/07 with six sowing dates, three in autumn and three in early spring. Subsequent harvests were made to determine the fresh and dry matter of leaves and beets. Furthermore, the development of foliage cover and light interception of sugar beet in spring were assessed by regular determination of leaf area index. The earlier the sowing date the higher were the yields of beet and leaves at a given harvest date. Accordingly, the leaf area index of autumn-sown sugar beet was considerably higher than that of spring-sown beet. Our findings suggest that one possibility to reach a high leaf area index earlier in year is to sow sugar beet in autumn. Although some leaves die off during winter because of frost, there will be a closed canopy much earlier than in spring-sown sugar beet. Thereby, a greater part of the intensive radiation in spring (April, May, June) can be used for a yield formation of sugar beet. At the moment the main problem of autumn-sown sugar beet is bolting after winter which might be solved by bolting resistance.