Here’s a trick my mum taught me. When you’re planning to be away for the weekend, or you’re just about to go to work on a hot, sunny Summer’s day, try placing a bag of ice cubes in your tubs or hanging baskets. Make sure there are small holes in the bottom of the bag to allow the melting ice to percolate through. It could make all the difference between a container-grown plant surviving your absence, or you coming home to a frazzled pot where nothing has survived at all. This is particularly frustrating when growing herbs, vegetables, or annuals from seed, nurturing them, potting the little beauties on, and cherishing their vulnerable existence only to find them having shuffled off this mortal coil for want of a few drops of water.
If you’re planting up a container from scratch, why not put in some empty 9cm pots that are spare. Sink them in so that they’re just showing above the soil surface, and use their empty void for filling with loads of ice cubes. Don’t forget to include moisture retaining crystals in your container compost. Modern products already have this included in the potting mixture. However, if you buy the crystals separately, it can work out cheaper as bog standard multi-purpose compost will then suffice, and this should be a lot cheaper than container/hanging basket compost.Simply mix in to the soil at the recommended rate shown on the packet, and away you go.
Remember that pots ought to be watered regularly and the soil kept reasonably damp, especially at the height of Summer, or on warm windy days. This will help to prevent the vulnerable shrubs, herbaceous plants and annuals becoming overly stressed. Place the pots, tubs and hanging baskets in a relatively shady area for the duration of your absence, use deep saucers where applicable, and maybe add a mulch of coarse grit to help stop the soil surface from drying out.