August is the latest month for taking semi-ripe cuttings. Fuchsias, Pelargoniums, evergreens, perennial climbers and most deciduous shrubs can still be propagated now, if you use the warmth of a glasshouse or tunnel to boost their growth.
Choose non-flowering shoots or cut the flowers off. Cut off slips 7-15 cm long by cutting just below a node (the thickening on a stem where a leaf or side shoot grows outwards). Clematis does better when cut between two nodes. Alternatively, tear off a side shoot of the right length with a piece of the main stem still attached like a foot, and cut off the ‘toe’ leaving the heel. Remove any leaves that would end up buried below the surface. Take plenty of cuttings: some won’t grow and the tighter they are crowded together the better they root.
Fill a container with a mix of two parts peat or leaf mould to one of sand, and water it well. Dip the bases of the cuttings in hormone rooting powder if you want, and lower them into holes dibbled around the edge with a pencil or similar. Firm the compost in well to ensure good contact with the cuttings.
The cuttings will lose water through their leaves and wither unless kept in the shade. Place them under solid staging, or rig up a shade above them. Use tinfoil or white plastic instead of black plastic, and keep it up from the plants to prevent heat build-up.
Lay clear plastic over the cuttings to keep in humidity. Hold it off the plants with hoops of wire or similar. Pelargoniums and plants with grey, silver, silky or hairy leaves resent humidity and are best left uncovered. Check the cuttings regularly and remove any dead bits. They are ready to pot on when they start growing.