You should finish harvesting frost-sensitive crops such as tomatoes, courgettes and beans before the first frosts. You can also pick the green fruit of tomatoes. They easily ripen indoors. The aroma of ripe tomatoes suffers if you store them in the fridge. The optimal storage temperature for ripe tomatoes is 12° C to 15° C.
Herbs lose their flavour with limited sunlight. So now is the ideal time to harvest herbs for the winter and to freeze or hang them to dry. You can divide perennial herbs after harvesting and rejuvenate them in this way. You can still continue to use frost-sensitive herbs in winter if you transplant them into pots and bring them indoors. Basil, chives and parsley are particularly suitable for this. Watering with a Super Strength Seaweed Extract strengthens the plants.
Cabbages are often prone to clubroot if they are repeatedly planted on the same area. This disease is caused by a fungus that lives in the soil and can survive for a particularly long time. Infected cabbages have clubroots that are swollen and knobbly. The plant fails to develop well, can be severely weakened and, in cases of very heavy infestation, can die. You must remove and destroy all affected plants. Do not plant any cabbages or other crucifers on the spot for the next four years. As a preventative measure, ensure that the soil has a regular supply of lime as a slightly elevated pH level inhibits the development of club root compared to the optimal pH value.
Harvested areas in the vegetable garden are suitable for sowing green manure plants, which are extremely beneficial in maintaining fertile soil. Winter vetches, crimson clover, lupins and winter rye are especially good for the vegetable garden as these can even be sown in September. Leguminosae can absorb nitrogen from the air, thereby fertilising the ground for the subsequent crop. It is still possible to sow phacelia as green manure at the beginning of the month.
September is a good month to plant rhubarb. Propagation is possible by dividing the rootstock. The planting soil should be humus-rich to ensure a good water-holding capacity. Increase the proportion of permanent humus by mixing in a permanent humus concentrate.