Feeding peonies: when & what fertiliser?


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At flowering time, peonies are a real joy in the garden. But in order for them to return year after year, peonies need to be properly fertilised. Find out all you need to know about feeding peonies.

A row of white peonies
Proper fertilisation promotes abundant flowering and healthy growth in peonies [Photo: alex172/ Shutterstock.com]

The genus of peonies (Paeonia) currently includes 32 different species – so it is no wonder that this type of plant has earned a place in so many gardens and delights garden owners with its sumptuous flowers. But in order to keep the vigorous, light pink flowering ‘Louise Mouchelet’ or the strong–growing ‘Gilbert Barthelot’ in this garden paradise long-term, one thing is particularly important: fertilising correctly.

Peonies are one of the more low–maintenance plants, after all, their roots reach even remote stores of nutrients in the surrounding soil. But the natural nutrient reserves they find are rarely perfect. For this reason, you should regularly fertilise your peony. Unfortunately, not every fertiliser is equally suitable for the flowering plants. Also, both the dose and the timing should not be random. We enlighten you on how and when best to provide a peony with nutrients.

Why fertilise peonies?

Nutrients are indispensable for plants to build up biomass, i.e. to grow up happily. It is no different for a peony. Pay attention to the right composition and concentration of energy transmitters, and you can promote lush flowering and vital growth. Peonies are particularly dependent on a good supply of nutrients in the growth phase, because in the cold season many species of the pretty flower overwinter underground as a rhizome. This is where all the nutrients are stored that are needed for the new shoots in spring. If the plant has not been fertilised sufficiently in the previous year, this deficiency is reflected in the nutrient storage of the rhizomes. In the spring, these plants then immediately have a less than ideal start to the growth phase.

Feedng peonies: when and how often?

With the budding of the peony after winter dormancy, fertilisation should also begin, after all, budding into the new year should be given the right support. The final fertilising is then done in July or August, before your peony blooms for the last time to say goodbye to summer. Later, you should avoid fertilising, because later shoots cannot harden off before winter.

If you use a slow–release fertiliser, you only need to fertilise at the beginning and end of the fertilisation period. With mineral fertilisers, you should provide your peonies with nutrients in small doses every four weeks. This is because, in most cases, these have only a very short–term effect and are easily flushed out of the soil. This not only shortens the watering interval, but also pollutes the groundwater. Therefore, and because of the high risk of overfertilisation, it is recommended to use an organic fertiliser when fertilising peonies. This also provides a long–term effect in a natural way and therefore only needs to be used twice a year.

Healthy and vividly pink peonies
Organic fertilisers have many advantages over mineral fertilisers [Photo: alex172/ Shutterstock.com]

Summary: when and how often to fertilise peonies?

  • The first fertilisation takes place with the budding following winter dormancy
  • Fertilise in July or August for the last time before the final flowering
  • With a slow release fertiliser, you only need to fertilise at the beginning and end of the fertilisation period
  • Mineral fertilisers are applied in small doses every four weeks
  • An organic fertiliser, unlike mineral fertilisers, poses no risk of overfertilisation and, because of its natural long–term effect, only needs to be used twice a year

Feeding peonies: instructions and fertiliser recommendation

Fortunately, because of their deep roots, peonies do not rely on an excess of additional nutrients, because they make use of a large area of soil and the nutrients stored in it. Therefore, the dose of nutrients is also highly dependent on the substrate in which your plant is growing. Sandy soil can store fewer nutrients than loamy soil. In this case it is important to improve the soil with proper plant fertilisation with compost and mixing in loamy soil. Also, it is very beneficial to know the exact variety of peony. While most varieties are quite frugal, there are breeding masterpieces like the fast–growing variety ‘Gilbert Barthelot’ that are a little more hungry for nutrients. In general, fast–growing varieties naturally consume more nutrients than slow–growing ones.

In the case of the peony, with all its aforementioned characteristics, a primarily organic slow-release fertiliser such as our Plantura Flower Food is therefore advisable. Nitrogen (N) should present in the lowest amount, as you do not need an unnatural growth spurt. Phosphorus (P) promotes, among other things, the formation of flowers, which is what gives the peony its special place in your own garden – for this reason, the greatest amount is needed here. Potassium (K) regulates the water balance, but is equally responsible for root growth and the frost resistance of the plant. It should therefore be second in terms of the quantity ratio.

Organic fertilisation of peonies

For most peonies, mineral fertiliser should be avoided, because with this type of fertiliser there is an oversupply of nutrients, which quickly overwhelms the plant. The reason for this is the slow growth habit of many peonies. The slow availability of a plant-based flower fertiliser with a long-lasting effect fits perfectly here. This should preferably also be of organic quality, so that the soil organisms can do their work well and happily. Our Plantura Flower Food contains a large amount of organic ingredients and provides these exact qualities – and almost exclusively based on plant source materials. The NPK ratio of 4 – 2 – 7 promotes healthy, bushy growth, vigorous flowering and helps your plant overwinter by strengthening it with potassium.

Young peony shoots
Mineral fertilisers often overwhelm peonies with an excess of nutrients [Photo: Dainty_Picture/ Shutterstock.com]

Slow release fertiliser: application recommendation for peonies

You cannot go too far wrong with organic fertilisers in terms of dosage, because even if too much ends up in the pot or bed, the same rule applies: overfertilisation is highly unlikely. But if you want to maintain your garden in the most environmentally conscious way possible, you should avoid unnecessary fertiliser applications. To ensure that fertilising your peonies does not end in unnecessary waste, we have a brief application recommendation for our Plantura Flower Food for you below. This fertiliser, composed almost exclusively of organic ingredients, when applied as follows, ensures happy peonies all year around:

  • Before planting, work 100 – 150 g/m² (well–filled 0.2–litre jar) of our Plantura Flower Food into the top layer of soil.
  • Water the soil and freshly planted peony well so the granules can dissolve entirely
  • During maintenance fertilisation in spring, you should fertilise it again with 80 – 120 g/m² (0.2-litre jar) per plant.
Flower Food, 1.5kg
Flower Food, 1.5kg
  • Perfect for flowering plants in the garden & on the balcony
  • For healthier plants with beautiful & long-lasting blossoms
  • Long-lasting fertiliser that is free from animal products - child & pet friendly

Mineral fertilisation of peonies

If you risk using mineral fertiliser for the neat perennials, you should never exceed the dosage recommendations given. Otherwise, the high doses of nutrients will quickly become too much for the frugal peonies. Also make sure that you only apply blue granules and the like with enough water. Otherwise, the nutrients cannot be absorbed and, in the worst case, burns can occur in the root area. Since a mineral fertiliser quickly does more harm than good with the peony, you should instead use an organic slow–release fertiliser. This is gentler on the plants and also considerably more environmentally friendly.

Feeding peonies with home remedies

Peonies in the bed are suitable for traditional fertilising with mature compost, goat, sheep or horse manure, or even bone meal. Work the natural fertiliser into the top layer of soil in the root zone twice a year. Covered with a fresh layer of soil, the release of nutrients can then start. But even in the pot, peonies can be cared for using home remedies. You can simply fertilise your plants with dried coffee grounds every four weeks. This is sprinkled in the root area or given with the watering water.

Fertilising potted peonies

Should the peony grow in a sufficiently large tub or pot, there are a few special features to bear in mind. First of all, shrub peonies are much more suitable for the pot than the perennial varieties. The reason for this is that the latter have markedly deep roots and are more affected by being in the pot. As well as this, the substrate of the pot should be rich in nutrients and there should be drainage at the bottom of the pot to avoid waterlogging (for example, made of broken earthenware or gravel). Fertiliser additions for potted peonies usually need to be applied more frequently than for outdoor varieties, as it is common for the plants not to bloom and fertilisers are used to provide them with constant growth or bloom stimuli.

Large light pink peony flowers
Flower buds are rarer on paeonias grown in pots [Photo: Natali22206/ Shutterstock.com]

Tip: It is a much better idea to provide peonies with a place in open soil, where they are much more eager to bloom and frost–resistant.

Another important care tip is proper pruning. This article will tell you everything you need to know about pruning peonies.

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