How to grow peonies in New Zealand

There are dozens of peony varieties, distinguished by their stunning layered flowers in a wide range of colours, blooming from late spring to the beginning of summer. With the right conditions, you can make the most of your peony blooms. Learn more about these beautiful flowers, when and how to plant them, and what kind of soil they need.

When to plant peonies in New Zealand

The best time to plant peonies is during autumn and early spring. Bulbs can be planted later, but this may result in delayed blooming.

Peonies will flower best in cooler climates; Northern gardens may be too mild for these blooms. It’s important to plant peonies before the first frosts, although they should establish well when planted in March or April.

Choosing peony varieties

Consider the variety of peony you are planting. Popular varieties in New Zealand’s climate include:

• Festiva Maxima
• Sarah Bernhardt
• Bowl of Cream
• Duchesse de Nemours

For container gardening, Chinese or herbaceous peonies are the best options.

Six tips for growing peony plants

1. Plant your peony in a sunny spot with well-drained soil, ideally protected from strong winds and frosts.
2. Ensure you have a reasonably large planting area, as peonies grow vigorously. Aim to plant no more than two peonies per square metre, with at least 30 cm between each plant.
3. Peonies thrive in soil that is rich, well-drained, and slightly alkaline. Adding compost or organic matter can help improve your soil for best results.
4. To keep your peonies healthy and flowering, feed them annually with a balanced fertiliser. Do this in spring as new growth starts to appear.
5. Peonies can grow in pots, but ensure you use a good-quality potting mix that drains well. Water regularly but be careful not to overwater. Herbaceous varieties are better for growing in pots than the tree peony types.
6. After flowering, remove spent blooms and tidy up the plant by cutting back dead stems. This helps promote strong growth for the following season.

Equipment list for planting peony plant

• Your chosen peony variety
• Scotts Osmocote® Compost & Soil Improver
• Garden shovel
• For potted peonies: Scotts Osmocote® Premium Plus Potting Mix, Scotts Osmocote® Controlled Release Fertiliser: Pots, Planters & Indoors, and a suitable pot or container

Cultivating peonies in the garden

When planting peony plants, prepare your location and soil and be sure to water the plant afterwards.

1. Select a sunny location with well-drained soil.
2. Dig up the soil and improve drainage if needed. You can add compost to enrich the soil and help promote healthy growth.
3. Plant your peonies relatively shallow. Ensure the buds (the ‘eyes’ of the plant) are no more than 3-4 cm below the soil surface. Planting too deep or too shallow can affect flowering.
4. Add a light layer of mulch, such as  Scotts Osmocote Mulch & Feed, around the base of your peony plants. This helps retain moisture, suppress weeds, and keep the soil temperature stable. Find out how much mulch you need.
5. Water the plants thoroughly after planting to settle the soil around the roots. Peonies like to stay moist, especially when establishing.

Growing peonies in pots in New Zealand

If you’re growing peonies in pots, it’s best to:

1. Select a large pot with good drainage holes to prevent waterlogging. Peonies need plenty of space for their roots to grow.
2. Place the pot in a location that receives partial shade. Avoid strong winds and drafts, as peonies prefer a sheltered environment.
3. Fill the pot with a well-draining potting mix
4. When planting, ensure the buds are no more than 3-4 cm below the soil surface.
5. During the colder months, move your potted peonies to a cooler, frost-free space like a basement or garage. This helps them go into dormancy and prepare for the next growing season.
6. Water your peonies regularly but ensure the pot doesn’t become waterlogged.

Peony plant care

Peonies are demanding plants. In poor soil, they may bloom weakly or not at all.

Fertilising peonies

Peonies can tolerate slight variations in pH, but they are very sensitive to nutrient deficiencies. They need plenty of phosphorus and potassium during their blooming period.

For this reason, it's important to enrich the soil with a suitable fertiliser. Fertilise your peonies at least once a year - you can also add compost to improve soil quality.

Troubleshooting issues: why aren’t peonies blooming?

Peonies need several years to establish themselves in one spot. So, if you’re transplanting them frequently, they’ll have trouble blooming. Only transplant your peonies if they fail to establish in their current location.

It’s particularly important not to move one-year-old plants, as they are still establishing their root systems. This is why it’s so important to choose the right spot in the garden from the very beginning.

When to cut back peonies in New Zealand

Cut back or ‘deadhead’ flowers that are spent or fading. This will encourage your peony to produce more flowers and new shoots. It's best to do this towards the end of winter or at the start of spring, to allow time for new growth.

Dividing peonies in New Zealand

The best time to divide and transplant peonies is during late summer through to autumn. This gives the plant enough time to establish roots before the winter and produce shoots the following spring.

Avoid transplanting on hot, sunny days, as the exposed roots could dry out. For this reason, it’s better to transplant peonies in the evening or on cloudy days.

Step-by-Step Guide to Dividing Peonies

Dividing and transplanting peonies is not difficult and involves just a few simple steps:

1. Dig around the plant carefully, ensuring not to damage the root system.
2. Gently lift the plant and trim the stems, leaving about 3 cm above the bud. It’s also a good idea to rinse the root system under running water.
3. After this, examine the roots and identify the thinnest sections. This will help you decide where to divide the plant.
4. Remove any damaged or mouldy parts of the roots.
5. Use a gardening knife or pruning shears to divide the plant into sections.
6. Treat the sections with a fungicide or rooting agent before planting.
7. Finally, plant the sections at the right depth and cover them with Scotts Premium Potting Mix.  It’s a good idea to plant the sections at a slight angle to encourage branching.

FAQs

When do peonies flower in New Zealand?

If planted at the right time, peonies will usually flower from mid-September through to December. However, peonies take some time to establish so it may be several years before you’ll see blooms.

Can peonies be grown in containers?

Yes! You can grow your peony plant in containers or pots. Just be sure to find a well-draining container, as peonies don’t like soggy soil. Ensure your soil is rich in important nutrients for peonies by using a quality potting mix, and find a sunny spot protected from strong wind and frost.