How do you get the best displays of autumn colour in your garden? Which flowers can you sow now for extra early displays next year? Are there any crops you can sow in September for late autumn harvests? Tune in for answers to these questions and many more in this a bumper edition of seasonal gardening advice from RHS experts. Plus Wisley horticulturist Alex Young shares tips on propagating houseplants.   Useful links: ►Find out more about growing trees and shrubs  ►Houseplants ►Sowing hardy annual flowers in autumn ►Grow your own fruit and veg Plants mentioned: Hydrangea quercifolia, Abelia grandiflora, Ceanothus 'Autumnal Blue', Gingko biloba, Sorbus 'Josph Rock', Parrotia persica 'Persian Spire', jewel orchids (Ludisia discolor and Macodes sanderianus), hardy annuals (Calendula officinalis, Nigella damascena, Cerinthe major), yellow rattle (Rhinanthus major/minor) - see RHS Find a plant for suppliers and more details Whitefly study details: please contact [email protected]