Dear Peony Grower,
Weeds:
Due to the variable Dutch weather with frequent rain, it is difficult to keep the Peony field weed-free, so it is wise to mow the crop, especially if it has largely died off. There is no point in keeping a crop standing if it has already been overrun by weeds. Preserving green parts means preserving growth. Even a crop going dormant contributes to the growth of the root. In fact, the strongest growth of the underground parts of a peony occurs during the going dormant phase.
Leaf nematodes can contaminate the field by hitching a ride on weed(seeds). Therefore, it is essential to have all weeds killed before winter. The peony is extremely sensitive to Roundup. Especially with meadow grass, this product should never be used on peonies. The plant absorbs the round up spray through its roots.
Leaf Nematodes & Rosebuds:
To limit the presence of leaf nematodes and rosebuds in peonies for the next harvest season, you can consider mowing the crop in early September. Leaf nematodes overwinter in dead leaves on the ground and in the young growing points of the peony. Mow the crop relatively early in the fall and remove the crop residues. Only do this in dry weather.
Botrytis Control:
Although the growing season has only just ended, preparations are needed to ensure a healthy crop in the spring. A key part of this is Botrytis control, which starts in late summer. It is important to apply a Botrytis treatment after mowing to kill wounds on the plant and spores present on the ground. These spores develop into winter spores, which cause “fallers” in the spring. This autumn spray is therefore as important as the spring treatment. Also, remove crop residues to prevent Botrytis and nematode infestation!
Mowing Height: Research shows that there is a Botrytis-suppressing effect when the crop is not mowed too short in the fall. This reduces the chance of fallers the following spring. A mowing height of 7-10 cm above the ground is better for the crop than mowing directly at ground level.
Watering in Greenhouses or Tunnels:
During this period, provide sufficient water in greenhouses and tunnels to allow for the absorption of nutrients. Dryness during this period harms flower production for the following year. An active soil life is important; moist soil and an adequate level of organic matter are crucial for promoting nutrient uptake.
Yellow Fruit Tree Cicada:
The Yellow Fruit Tree Cicada is becoming more common in peony crops in greenhouses. Since the cicadas only appear after flowering, they are not harmful in small numbers. Most cicadas appear in August. In September, the cicada lays its eggs. Perform control measures in August, but be aware that you probably won’t eliminate the problem in one go.
Leatherjackets:
Adult crane flies consume only a small amount of nectar. However, their larvae, known as leatherjackets, are much more voracious. They are relatively large, soft, and thick and feed on various plants, including the stems of peonies just below the ground.
Life Cycle:
The crane fly has six developmental stages: an egg stage, four larval stages, and an adult stage. Adult crane flies live for only a few days. Some species have one generation per year, while others have multiple generations through the year. This means that there are larvae throughout the year that can cause damage.
Signs of Damage:
During the day, leatherjackets remain in the soil. At night, they emerge and feed on the base of the stems and the lower green parts of the plant, they are also pulling the crop slightly into the ground. Stems with damaged bases wilt.
Measurements:
Biological control can be achieved using parasitic nematodes such as Nemasys H, C, or F.
Nematode Sampling:
The optimal time to determine if there is a harmful nematode infestation is in the fall, since their numbers are the highest at that moment and this will provide a sample with the most information. Choose a sample that includes incubation, so nematodes in root residues are also considered. Discuss the results with your advisor and consider them in your crop plan, including when selecting green manure for the next growing year.
Phytophthora:
Infection occurs in wet conditions through wounds. The fungus can survive for years in plant tissues or soil. The first signs of infection are black, limp leaves. In spring, Phytophthora causes brown to gray-black spots on stem parts, and these branches develop small black hooks and grow no more than 10 cm. Once infected, it is nearly impossible to eliminate. The spots often feel spongy and soft, with the pith dark brown and rotten. Varieties like Kansas and Duchesse are susceptible for this. Chemical treatments can lead to zoospore mutation, so rotating treatments is important. Manganese and zinc provide resistance to Phytophthora. Spray preventively (once every two weeks) from emergence until mowing with products such as Copper, Pergado V, Paraat, Axidor (systemic), or Ranman Top.
Phytophthora is easily confused with frost damage. In both cases, the plant’s top turns black-brown, dries out, and bends down. The difference is quickly apparent, as frost damage leaves a hollow in the stem at the boundary of diseased and healthy tissue. Severe leaf nematode infestation can also cause a withered top, but the top does not bend down, and small, partially formed leaves are often visible. Therefore, it is advisable to have suspicious plants examined for Phytophthora to avoid unnecessary use of costly crop protection agents.
Measurements:
• Use healthy planting material
• Ensure good soil structure
• Avoid waterlogged soil and ensure adequate drainage
• Avoid high soil salt content
• Regularly add a Phytophthora treatment when spraying for Botrytis
• Be cautious when tilling to avoid damaging roots, which can lead to Phytophthora infection
• Early mowing increases stress, making the plant more susceptible to Phytophthora
• Excess nitrogen makes the plant more vulnerable
• Increase plant resistance by planting with Trichoderma, for example
Chrysal Vident:
What does Vident do:
• Chrysal Vident reduces Botrytis infection in cut flowers after harvest.
• It is a fungicide based on fludioxonil that inhibits spore germination and the growth of germ tubes and mycelium.
Application:
• Chrysal Vident can be used as a dip or spray treatment.
• Dip the flowers in a tub filled with the solution or spray with a Birchmeier or Gloria backpack sprayer when storing the flowers in cole-crates.
• Place the flower buds outward and spray.
• The product is intended for use by the grower and importer.
• Dosage: 0.5 ml Chrysal Vident per liter for dipping, and 10 ml per liter for spraying.
• The use of a wetting agent is recommended for proper distribution of the spray liquid.
• Dip the flowers for a few seconds in the solution or spray them until the liquid runs off.
• For dipping, it is recommended to prepare a fresh ready-to-use solution daily.
• It is important to always use clean tap water!
• Used dipping solution can be topped up with fresh solution during the same day.
Benefits:
• Less spoilage due to Botrytis
• More beautiful flowers for the consumer, improving ornamental value
• Longer vase life for the flowers
Green Works Care™
Green Works has developed an effective and environmentally friendly method for controlling nematodes in peonies. This is done in collaboration with institutes and universities in the Netherlands and abroad. This method, called ‘Green Works Care™ for peonies,’ is available exclusively from us. It has been extensively tested over several years and offers a viable alternative to the standard hot water treatment. . ‘Green Works Care™ for peonies’ even has major advantages over traditional hot water treatment.
The advantages of Green Works Care™ include:
• The plants do not dry out during the treatment of Green Works Care™
• The Green Works Care™ treatment is environmentally friendly and sustainable
• Special preventative treatment against root knot and leaf nematodes
• More vigorous growth in the first year
• Higher yield of flower stems per plant in the second year
• There are no chemicals used in the whole process
• Due to this the risk of chemical resistance will be eliminated
• Safe for humans, animals, and the environment
Storing Peonies After Receipt:
The best time to plant peonies is during fall. In cool periods (fall), the plant roots better, leading to more growth in the spring. Therefore, try to plant the peonies before frost sets in. Peonies planted in the fall should not be stored in refrigeration. If the cooling period is too long, the plant may start growing before winter, resulting in frost damage in winter or early spring.
During the period from September to November, do not refrigerate.
• The drying out of the roots is disastrous for the peony.
• After receipt, store the peonies in the shed or cold room (not in a draft).
• Adequately cover the pallet with peonies (with moist jute sacks) or wrap them.
• Do not direct a fan or cooling unit fan at the plants to prevent drying out.
• Before planting, soak the peonies in water for fifteen minutes.
• Plant in moist soil.
• Plant at a depth of about 5 to 8 cm with soil covering the roots.
• After planting, rain in the peonies so that the soil settles around the roots.
• If the soil structure is not good, it is better to plant later when the soil structure has improved.
• If peonies cannot be planted in the fall due to circumstances, they should be stored after January 1st at a temperature of -2°C, packed in dry peat and a plastic bag with small ventilation holes to prevent drying out.
• If peonies need to be transported in the fall, it is best to ship them at a temperature of 2 to 5°C to avoid high temperatures and mold formation.
New Planting:
Preparation:
Soil test: determine major and trace elements and organic matter content + nematode sample
• Optionally add compost
• Ensure very good drainage
• Free of root weeds
• Good soil structure
• Pre-crop due to nematode infestation
• Timely weed control
• Visit the auction for orientation and inspect the plots where peonies are grown for tuber production (long-term purchase).
Planting Time:
• Make a planting schedule
• Outdoors: September to March (fall is the best time)
• Set the buds/eyes upright
• Soil preparation is very important for structure and water management
• Drain the land
• Plant in moist soil
• Consider spray beds / flower emergence
• Take future tunnel placement into account (harvest spreading / higher yield).
Planting Depth:
Planting depth of 5-8 cm of soil covering the roots (planting too deep results in fewer flowers).
When planting peonies in fall 2024, the benefits of the extra investment in 3-5 eyes versus 2-3 eyes:
| Aantal stelen/ bloemen bij planten 2-3 of 3-5 ogen: |
| Example | Year | Number of stems | Number of stems | |
| 2-3 eyes | 3-5 eyes | |||
| Sarah Bernhardt | Planting in fall | 2024 | ||
| Spring | 2025 | 0 | 0 | |
| Spring | 2026 | 0 | 3 | |
| Spring | 2027 | 4 | 7 | |
| Spring | 2028 | 6 | 8 | |
| Spring | 2029 | 7 | 9 | |
| Spring | 2030 | 7 | 9 | |
| Spring | 20231 | 8 | 9 | |
| Etc. | 32 | 45 |
In the link below, you will find our extensive and updated peony assortment for 2024–2025.
Click here for our 2024–2025 Peony Catalog!
Green Works also supplies other summer flower starting material, like: Ranunculus Butterfly™ series, Ranunculus Romance™ series, Oxypetalum Bridal Series®, Scilla peruviana, Pericallis and Asclepias Beatrix®.
For more information, please consult our website or contact:
Ed Kleijbeuker tel. 0031 (0)6 24 94 64 05 | ed@green-works.nl
Daan Kneppers tel. 0031 (0)6 51 82 47 12 | daan@green-works.nl
Also, follow Green Works on, Facebook, Instagram and LinkedIn for more relevant information about Peonies.
Green Works is the grower specialized in young planting material for Peonies, Ranunculus, special pot plants and summer cut flowers. Green Works also is a large grower of peonies for the successful cultivation for cut flower and trade, in the Netherlands and abroad. We supply within the Netherlands and globally to professional growers and (export) traders. With support in cultivation, promotion and sales, Green Works offers a total package to put an unique and healthy product on the market: www.green-works.nl/en
Green Works can never be held liable for any cultural information given and only to be used as a guideline. The grower is at all times responsible for his own action and to read the label of the chemicals being used.
