Plant summer baskets from April onwards, but protect them from frosts e.g. in a greenhouse until the end of May. If this is not available wait until late May to plant them up outside.
Hanging baskets need three types of plants: ‘Thrillers, Fillers and Spillers’. The Thriller is the taller plant that features as your centrepiece creating structure and impact. ‘Fillers’ are planted around the central plant, and ‘Spillers’ are planted at the edge of the basket to trail over.
How many plants should make up the basket? A general rule of thumb is one plant per inch of basket diameter, so use 12 plants in a 12 inch (30cm) diameter basket. If you are planting strongly-growing plants e.g. Fuchsias or Geraniums then use only five in a 30cm basket
Plants suitable for summer baskets include:
These are all readily available from garden centres, nurseries and online suppliers.
Before you start
Ensure that your basket is the right size for your hanger and bracket. Different hanging baskets and liners are available e.g.
Optional – Plant some plants through the sides of the liner. To start, mix the compost, fertiliser and gel together. Put a layer of the compost mix in the basket and insert some plants through the sides of the liner.
With a coir liner, cut ‘cross shapes’ to make it easier to insert the plant roots. Wrap paper or polythene around the roots when inserting the plants to prevent damage. Fill in between the plants with compost mix. Add more plants and build up the compost. Finally, plant ‘on the top’ with a Thriller plant and Fillers and Spillers.
Add water-retaining gel to the compost which can dry out quickly in warm weather. The gel slows down the drying process.
Check the compost each day (finger test) and keep the compost moist but not soggy. When watering, water the compost and not the foliage or flowers. This helps the water reach the roots where it is needed rather than be wasted as it evaporates from the leaves. Water-drops on leaves in bright sunshine act as tiny mirrors and cause scorch marks.
Deadhead the flowers every week to promote more flowering. Don’t be afraid to give your plants e.g. Petunias a good ‘haircut’ to tidy them up and give them a growth boost, if they become too straggly.
Use slow-release fertiliser pellets (moisture dependent) or controlled-release fertiliser pellets (temperature dependent) in your basket but check how long they last e.g. six weeks. Mark the date in your diary and then re-apply after this time. Alternatively use a weekly liquid fertiliser; feed with a high Nitrogen (N) content in the first weeks to encourage plant growth and then later with a high Potassium (K) content to encourage flowers.