How to look after summer pots
It is important to get the potting mix right. Mediterranean plants such as lavenders or pelargoniums will always do better with extra grit added to the compost. Big pots, crammed with flowers that you are expecting to give months of top-quality performance, will need the mix boosted with homemade garden compost, and ideally some leafmould to improve the root run. They will also need feeding and watering regularly. It is always helpful to have a tap on, or near, any patio area and a dedicated watering can or two always to hand.
In general, pelargoniums are very simple plants to grow, and the tougher you treat them, the better they flower. In fact most problems with pelargoniums are due to overwatering rather than underwatering. They are adapted to very harsh, dry conditions and need only minimal watering, especially during winter. Whatever the time of year, let the compost completely dry out between each watering. If the leaves start to become tinged with orange or yellow, it’s an indication to ease back on the watering for a while.
To make any pelargonium grow rapidly, simply repot it repeatedly into a slightly larger container before it starts to flower. If you keep doing this, it will continue to grow vigorously until its roots become constricted. Then, when it is as big as you want it, leave it in the pot it is in and as the roots become increasingly constricted it will flower profusely. Conversely, if you have a plant that has become too big and unwieldy, you can simply cut cleanly across the stem about a foot from the base, and it will regrow vigorously.