How to grow polyanthus

Growing polyanthus flowers

Polyanthus are a wonderfully vibrant flowers to grow at home. If your garden could use a pop of colour and a general cheering up then polyanthus could be the right flower for you. Polyanthus are a herbaceous ornamental flowering plant which are a cross between Primula and polyantha belonging to the family Primulaceae. Another common question people ask is what’s the difference between primulas and polyanthus? Primrose and Polyanthus are both part of the Primulaceae plant ‘family’. The main difference between them is that primroses have the flowers close to the leaves whereas polyanthus flowers are on longer stems. Polyanthus is technically a perennial, although works best as an annual.

If you have ever wondered how to grow polyanthus in Perth then look no further. Perth has good Polyanthus growing conditions and they are a popular flower in summer and autumn. Polyanthus are a relatively easy flower to grow, and there are a few tricks to successfully growing polyanthus in Perth, Western Australia. Get these right and you will be laughing.

When to plant polyanthus:

The best time to plant polyanthus seeds in a Mediterranean climate zone like Perth is late summer or autumn.

Plants will grow in full sun, however, you will get a more intense flower colour when grown in part shade.

How much water do polyanthus need:

Polyanthus need regular watering. Aim to keep the soil moist, but not wet; free-draining soil is ideal and sandy soils are fine, just blend in some compost when planting to to help the soil hold onto more moisture. Adding a soil wetting agent is also recommended.

Don’t plant in waterlogged areas as this causes problems. The centres of the plants will rot away fairly quickly. With plants growing in pots, don’t leave the pots sitting in saucers of water either.

Types of polyanthus:

Polyanthus come in a seemingly endless selection of colours and vivid polyanthus flower patterns. Check your local nursery or Bunnings store to see what’s available in your area. They are often sold in a punnet as a mix of colours. Polyanthus pacific giant is a common variety in Australia.

  • Polyanthus Pacific Giant – A bright polyanthus mix bearing abundant colourful flowers with golden yellow centres on strong stems.

How to grow polyanthus at home:

Growing polyanthus at home in the garden is pretty straightforward. They are great for planting in garden beds, along borders, pots, window boxes and hanging baskets alike. Follow these simple polyanthus growing tips for planing in the garden;

  1. Choose a spot in the garden that receives full sun to part-shade with well drained. Enrich the soil with a dynamic lifter and soil improver.
  2. Dig the planting hole twice as wide and to the same depth as the root-ball. Remove the shrub from the container, gently tease the roots.
  3. Position in hole and back-fill with soil, gently firming down. Form a raised or doughnut shaped ring of soil around the outer edge of the plant’s root zone. This helps keep water where it’s needed. Always water in well after planting to settle the soil around the roots and keep the soil moist for several weeks while the new plant establishes.
  4. Mulch around the base with organic mulch like wood chips, keeping it away from the base of the plant.
  5. Feed every 2 weeks with a Liquid Plant Food suitable.

How to grow polyanthus in pots:

You don’t need a large space to have your very own polyanthus. Growing polyanthus in pots is easy, fun and rewarding! In general growing polyanthus in pots is a great idea. Below are the steps on how to how to grow polyanthus in a pot;

  1. Choose a pot at least 20 cm wide and deep. Position in full sun to part shade.
  2. Fill the chosen pots with quality potting mix
  3. Remove the from the container, gently tease the roots.
  4. Position in hole and back-fill with potting mix, gently firming down. Water in well.
  5. Feed every 2 weeks with a Liquid Plant Food suitable.

How to fertilise polyanthus:

Whether in the garden or in pots, don’t let them dry out. Add a fertiliser high in potash such as Yates Thrive Roses & Flowers Liquid Plant Food to the watering process once a fortnight. Trim off any dead flowers and leaves to keep them looking good and blooming right through winter. This will help to keep your plants disease free also.

When do polyanthus bloom:

Flowering period is during spring. Removing spent blooms is a good idea to encourage further flowering.

How long do polyanthus flower for:

The flowering window for polyanthus is from July through to October. Look after your polyanthus by removing any yellow leaves as they appear, and snipping off any dead-heads with secateurs to keep the plants looking neat. After flowering, the plants can be lifted and moved or left to naturalise.

Companion plants for polyanthus:

Because they are so vibrant and come in so many colours polyanthus look great standalone. However, here are some ideas of the flowers you could choose as companion plants for primulas and polyanthus. Bedding Daisies, Bugle, Daffodils and Forget-me-nots (Myosotis) will work well as companion plants.

Polyanthus care and common problems:

The biggest challenge with polyanthus is keeping them away from snails and slugs which leave large ragged holes, chew marks on leaf edges. Manage with pellets as required. It’s also important to keep them fertilised with a flower plant food every two weeks which is high in potash.

Check out our other how to grow in Perth guides:

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