Peony care newsletter, January 2016

Herewith we send you our Peony Care Newsletter. Information currently relevant to the crop of peonies will be given special attention. We trust that this information will be helpful in achieving a successful crop. Please contact us when you have any questions or comment.

Weed control

Weed control in peonies is not without problems. Especially now, and with this we mean before the growth of the eyes, it is best to spray Kerb in combination with Chloor IPC. Kerb and Chloor IPC work very strongly at low temperatures (lower than 12C, but best around 5C) against seed weeds like e.g. chickweed and stinging nettle. Chloor IPC works best on moist soil in cloudy weather. With warm weather results will be minimum. Never spray in the rain. The rain will let the herbicide soak in the soil and this will cause damage. When the new shoots appear above the ground never spray Chloor IPC. Contact with Chloor IPC on the peony means that the plant will not grow that season.

Do not use the herbicide Stomp in the greenhouse as this will cause damage to the plant. When the new shoots are visible you can still spray with Goltix and Olie-H. Goltix is best used on a moist soil. Do not spray during sunny weather, spray close to sunset. Also do not use Goltix when night frost is expected.
The herbicides Basta and Linuron can never be mixed, but use after one another to prevent damage.


The first treatment against Botrytis will have to take place when the plants start to emerge. Due to the fact that the fungus  lingers during the winter at the surface of the soil, the new shoots will be infected during emerging from the soil. Drenching the soil with Collis can reduce the number of infected plants, for example with a sensitive variety like Flame, by more than 90%. Peonies damaged by the wind and frost are also more sensitive. Varieties in which Botrytis was more present the previous season after flowering, need extra care. Therefore we would like to emphasise the need to treat plants timely and preventively. There is an advantage in doing so. The dosage is maximal 4 litre per ha and works best when as much as possible is drenched on the plants with lots of water (for sensitive plants 0,20 litre per plant). Using Collis regularly is not an option because of resistance. Loosening the top soil in the poly houses and greenhouses can reduce damage by Botrytis.
Because of its fast growth the peony it not very resistant to changes in climate. Around the damage due to this, Botrytis will most likely appear. Especially when peonies are not protected sufficiently during growth, the fungus will cause large problems. Extra spraying is most definitely needed during this critical period. As good and effective products mostly Teldor, Kenbyo and Switch are used.

Take soil samples regularly so that you will get a better picture on the needs of your plants.


Who is Soiltech?

The resilience of the soil and the plants that grow in it is created primarily by nature itself. This is the philosophy behind Soiltech’s soil analyses and tailor-made fertilisation advice for tree, ornamental, fruit and vegetables growers and public landscaping projects. Soiltech has a broad range of products in order to achieve sustainable cultivation and drastically reduce the use of chemical products and increase growth of the plant.
The total system Soiltech focuses on increasing soil resilience and optimal nutrition for the crop.

Are you prepared for the coming season? Perform a soil analysis!
It is the beginning of the year and the cultivation is on hold. Time to take stock. Not only of the income and costs but also of the most important part of the cultivation: the soil. Does it still have the right balance? Are you making use of everything it has to offer? A soil analysis answers all those questions.

What is a soil balance analysis(SBA)?
A soil balance analysis (SBA) reveals the ratios of the various minerals and trace elements in your soil. The soil balance is determined on the basis of the TEC (Total Exchange Capacity). This value indicates the soil’s clay-humus complex, and hence its potential for retaining minerals and supplying them to plants. The SBA also determines the concentrations of the various cations on the clay-humus complex. This reveals the ratios of the various cations in your soil. It is very important to know what these ratios are, as this tells you which nutrients to apply to your soil to bring it into balance. These nutrients vary per soil and variety. We are glad to help out with a personalized fertilization advice.

Everything depends on a good preperation
This is a perfect month to get an SBA done. There is almost no cultivation done and the soil has come to rest. This is important to get the most reliable information. Because the soil samples are being analyzed early in the year there is still plenty of time to resolve any complications in the soil. This will make sure that the soil is in optimal balance at the start of the new season!

Why do a SBA?
An SBA checks the overall need of the specific soil. In contrast to some other analyzes where they work with a region average for measurements. The SBA gives a specific advice per element of the sampled soil.
Contact your advisor for tailored advice.
Jelle Havermans: +31 (0)6 – 51 13 47 80


Top quality peonies require a good fertilizers. Peonies that have been growing for a couple of years can exhaust the soil and surely need fertilizer.
It is not for nothing that the peony has been called a high fertilizer requirement summer flower. In the first stage of the growth the plant needs nitrogen (N). Take care that the nitrogen is available for the plants on time. Applying at a later moment, thinking that the peony will be stronger and less long, is not correct. When the peony does not have enough fertilizer available, the stems will be weak and the plant will be more susceptible to Botrytis. Some more leaves on the plant will make it possible to keep some leaves on the plant during the harvest so next year the plant will be productive. Extra length of stem can be achieved by an extra spaying of ammonium nitrate.
Keep in mind that nitrogen not only causes the green leaves to grow, but also the flower leaves! More nitrogen produces larger flowers.

Main Elements

Nitrogen is the element that is most easily absorbed by the plant. During strong growth and in the first weeks at the vegetative stage (length growth) lots of nitrogen is needed. A lack of nitrogen will cause a light green leave colour, less growth of length, flowering too early and susceptibility to fungus diseases.

Phosphate works favourable in forming the main root system. Several weeks before the flowering phosphate, together with potassium, improves the forming of the flowers. It is advised to apply extra phosphate and potassium before flowering time. Lack of phosphate will result in smaller leaves, less colourful flowers, possible later flowering and red purple colouring of the leaves. Too large an application of phosphate will result  in that the plant cannot take up magnesium and thus results in a lack of magnesium.

Potassium ensures firm leaves and stems and at time of flowering it takes care of, together with phosphate, larger and full flowers. With enough potassium a plant can protect itself better against fungus and bacteria. A lack of potassium will cause yellow leave edges, also leaves will get smaller and stems thinner. Too much potassium causes salt damage and poor plant growth.

Magnesium gives the plant its fresh healthy green appearance. It also has a function for the cells and the firmness of the tissue, and it is a building stone for several enzymes. When there is a shortage of magnesium you will see the leaves turn yellow while the leave nerves will stay green. Too much magnesium does not occur.

Calcium is used by the plant for firmness and build up of the cells. Calcium is very important for the water regulation of the plant and is indispensible during higher temperatures. At a high temperature the plant will evaporate a lot and needs to take in more water. Shortage of calcium occurs when the growth is too fast and the humidity is too high, causing less evaporation in the plant. When the plant cannot evaporate, it can also not absorb any water with plant food. Young leaves will wither, and the plant will be more susceptible for fungus diseases.

Micro elements are the vitamins and minerals for the plant. Micro elements are: Fe = Iron, Mn = Mangane, B = Borium, Zn = Zinc, Cu = Copper and Mo = Molybdene. All these elements have an important function and are the building stones of the plant. Micro elements are also needed for the water regulation, dividing of cells and metabolism of the plant. The micro elements are absorbed by the plant through its roots so it is very important to grow strong roots on the plant. Because the plant food we buy in the trade contains very little to no micro elements it is important to apply those during every feeding.

Normal fertilizing kg/ha for peonies on yearly basis:
(at normal soil valuation)

N- demand: 200 kg/ha
Phosphate, kg P2O5: 100 kg/ha
Potassium, kg K2O: 225 kg/ha
Magnesium, kg MgO: 100 kg/ha
Before start of growth it is possible to fertilize with:
Organic materiaal
Nitrogen (N)  Apply 125 kg before flowering
Potassium Only apply halve

During the winter a supplement of compost is advisable, especially for the parcels with the more mature peonies.

All plant food needs to be applied in the correct proportion to each other or a limited factor we call antagonism will develop. Which also means repression. The plant food element more present and higher in power will repress the food element that is less present, and because of this it is not absorbed by the plant. For example an application of too much Potassium represses the absorption of calcium, but too much calcium can cause larger problems because calcium represses almost all plant food except nitrogen.



What are DCM organic fertilizers?
Organic fertilizers are composed of different vegetable (like malt meal, cocoa shells, meal of oil cakes, tobacco dust, vinasse) and animal raw material (like hoof meal, bone meal, feather meal, hair meal) of natural origin. The nutritional elements (nitrogen, phosphate and potassium) in these fertilizers will release after soil organism, like bacteria and fungus, are breaking down the fertilizer grains. By this process of slow decomposition and the use of several raw materials the nutrients are released to the plants over a longer period of time, approximately 100 days.

Advantages of DCM organic fertilizer as opposed to chemical fertilizer:
Chemical fertilizers are fast soluble salts, that will come available to the plant roots in one time. A surplus of plant food, with a chemical fertilizer, can cause root damage. The plant cannot absorb the large quantities of available plant food and a large part of the nutritional elements will be lost by drainage.
With DCM organic fertilizers the nutritional elements will be released to the plant according to the need of the plant. During warm and moist weather, when the plant grows fast and thus needs more nutrients, the decomposition of the fertilizer and also the release of the nutritional elements will be quicker. Because release and absorption of the nutritional elements are matched, all nutritional elements are absorbed by the plant. Almost none of the elements are lost by drainage and there is no risk for damage to the roots. Organic fertilizers do not only work effectively for a longer period, they are also environmentally friendly and save for the plant.
Besides this organic fertilizers improve the composition of organic material in the soil which in turn is favourable for other soil organism.

DCM fertilizers for the cultivation of peonies
In the cultivation of peonies several organic fertilizers are being used. Difference is made between inside- and outside growing. Below a list of products being used mostly for this:

Inside growing

  • Mix 2 (7-6-12+4MgO) – granular fertilizer with higher potassium for strong leaves
  • Micro-mix – granular micro elements mix (encompasses iron, mangane, copper, borium, zinc, molybdene)
  • Vivisol – granular, creates a rich and variegated soil
  • Olega fer – quick working iron leave nutrition

Outside growing

  • Mix 5 (10-4-8+3MgO) – granular fertilizer
  • Vivikali – slow release organic potassium
  • Vivifos – slow release organic phosphate (also good available with high pH)
  • Olega fer – quick working iron leave nutrition

For custom advise you can contact your advisor or Mark van Dulmen of DCM Fertilizers (06 – 51 31 04 92 or

Slugs: the sneaky killer in your peonies!

In the winter and the early spring slugs can cause at a lot of damage under glass but also in your field peonies. Therefore, be alert for gluttonous slugs and prevent damage on your peonies.
Slugs (without a shell) and snails (with a shell) are molluscs. Slugs mostly appear under glass. They can cause a lot of damage in many varieties. They are not very particular in their choice of food. Slugs prefer young growth, leaves but also the sprouts of your peonies.
Because slugs and snails are active at night and retreat during the day, they are not easily found on the damaged plants.
Damaged plants can be susceptible for all kinds of fungus diseases.

Next to Peonies Green Works also supplies planting material for summer cut flowers like: Asclepia Beatrix® en Helleborus Orientalis Queens™ 


When you have questions, want more information or are interested in Peonies please contact:

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