Fertilize hydrangeas: tips on when and how to proceed

In order to be able to develop their full bloom, hydrangeas must be properly fertilized. You can find out when, how and with which fertilizer you should fertilize your hydrangeas here.

hydrangeas (Hydrangea) are among the absolute classics in our gardens and have lost none of their special charm. In order to be able to benefit from their flowering dream, the hydrangeas must be supplied with nutrients on a regular basis. Because the nutrition of the hydrangea determines whether the plant is vital and sets the course for the formation of the flower color.

Any type of hydrangea can develop into a healthy and vigorously flowering beauty with the right fertilization. In addition, the popular peasant hydrangeas (Hydrangea macrophylla) laid the foundation for the flower color. This is mainly influenced by soil pH and to a lesser extent by fertilization. In this article you will learn more about the Blue coloring of the hydrangea flower

and the following paragraphs should deal with when, with what and how hydrangeas in beds and pots are properly fertilized.

When is the best time to fertilize hydrangeas?

When planting, an organic long-term fertilizer should be incorporated. The slowly released nutrients and the activation of the soil life are a good basis for the establishment of the new planting at the new location. By the way, hydrangeas are planted either in spring (March - May) or in autumn (October - November). Established hydrangeas are fertilized once a year outdoors and twice a year in pots because of the smaller substrate volume.

Tip: When planting new hydrangeas, keep in mind that they like to be acidic to neutral. If you want to achieve peasant hydrangeas with blue flowers, you even need a pH value of around 4.5. Oak leaves, grape pomace, clippings from Rhododendrons and other ericaceous plants as well as coniferous wood chips or peat lower the pH value for the hydrangeas.

Fertilize hydrangeas in the bed

As a rule, hydrangeas are quite fast-growing and are therefore often planted in beds. If you have one organic fertilizer use, one fertilization per year is already the whole effort that they have to make for the nutrient supply. However, this one fertilization should be between March and May, because late and High-nitrogen fertilizers cause the plant to suffer frost damage - and flowering in the following year is cancelled.

Should you have one mineral fertilizer want to use, it must be applied monthly and depending on the product recommendation. Long-term mineral fertilizers can save you this work. However, they are more likely to damage hydrangeas in the long term, as you will learn a little later.

Summary when to fertilize hydrangeas:

• Hydrangeas should be planted and fertilized when planted in spring or autumn
• Hydrangeas in the bed only need to be fertilized once a year (March - May) with organic fertilizers
• Fertilizing too late with nitrogenous fertilizers leads to failure of flowering in the following year or even to frost damage
• Fertilizing with mineral fertilizers may be more time-consuming and not beneficial for the hydrangeas in the long term

Digression: three reasons why your hydrangea is not blooming properly

1. Excessive pruning: hydrangeas mainly bloom from last year's wood, which is why everyone Maintenance cut in spring only thinning and removal of dead and frozen shoots is operated
2. Frost damage: Last year's shoots are frozen back and the flowering sites are also lost; Frost damage is often the result of too much or too late fertilization with nitrogen
3. Too humid between June and August: the hydrangea pushes through instead of flowering.

Fertilize hydrangeas in the pot

The same applies to planting potted hydrangeas as to outdoor hydrangeas. However, hydrangeas in the pot must then be treated a little differently than those in the field. On the one hand, their substrate volume is much smaller than that of their relatives. On the other hand, pot hydrangeas are often overwintered frost-free to protect the pots and plants. As a consequence, the potted hydrangea is given a two-part fertilization: It receives two thirds of its nutrients between March and May and the last third between June and August. Of course, this only applies if you are using an organic fertilizer that is not overly nitrogenous. With mineral fertilizers with an emphasis on nitrogen, you should refrain from fertilizing this late and preferably only from March to June regularly and according to the fertilizer manufacturer's recommendations for use fertilize.

Summary of fertilizing hydrangeas in pots:

• Potted hydrangeas should be planted and fertilized when planted in spring or autumn
• Potted hydrangeas need to be fertilized with organic fertilizers twice a year (March - May and June - August).
• Hydrangeas in pots must be fertilized with mineral fertilizers regularly and according to the manufacturer's recommendations - nitrogen supply after June should be avoided

Which fertilizer is the best for hydrangeas?

Anyone who sees their garden as a growing and developing place to feel good should rely on fertilization that is as natural, long-term and sustainable as possible. That includes one in mineral fertilization however, because mineral fertilizers only satisfy the needs of plants in a very one-dimensional way. They only provide nutrients, but let the quality of the soil suffer. For example, the humus content decreases. There humus is an important water reservoir and hydrangeas depend on a good water supply, they ultimately suffer from mineral fertilizers - and you have to water them more and more frequently. The choice of organic or organo-mineral slow-release fertilizers, on the other hand, has the following advantages, among others:

• Maintaining or even increasing the soil humus content and thus the water retention capacity, nutrient storage capacity, root penetration and aeration of the fertilized soil
• Entry of important trace nutrients that are usually missing in mineral fertilizers.
• Resource-saving production of an environmentally friendly fertilizer for fertilization without serious consequences for people and nature

We have developed a hydrangea fertilizer that meets all these criteria and even goes a little further: it is based on animal-free raw materials from the food, luxury goods and animal feed industry as well as mineral components, which are also used in organic farming will. So that's ours Plantura organic hydrangea fertilizer truly "organic" and therefore ideal for sustainable gardening.

Fertilize hydrangeas correctly: instructions for ideal application

When dosing fertilizer, you should always follow the manufacturer's specifications closely. This will prevent your hydrangea from becoming deficient or showing symptoms of overfeeding. For our Plantura organic hydrangea fertilizer we can provide you with the following guide:

1. For new plantings 150 grams per square meter or Work 50 grams per plant into the bed or lift under the potting soil and the excavation of the planting hole.
2. Water generously to loosen the fertilizer granules. This helps to initiate the conversion and thus the nutrient release.
3. Outdoors, annual fertilization is carried out between March and May at 60-80 grams per square meter or 25 grams per plant. The granules are worked in flat and then watered well.
4. Hydrangeas in pots are supplied with 3-5 grams per liter of potting soil in March/April, and with 2-3 grams per liter of potting soil in June/August. If possible work in flat and pour on.

Tip: Often it is not so easy to weigh the volume of a pot. Sometimes it helps to hold a bucket with a defined volume (e.g. a cleaning bucket with 10 or 20 liters) next to the pot and estimate its size.

Fertilize hydrangeas with minerals: Blaukorn & Co.

The application mineral fertilizer is based on the assumption that a plant needs water, light and the 14 essential nutrients to live - nothing else. However, what was long considered certain has been refuted for several years: plants interact with the soil in which they grow in a variety of ways. Ninety percent of all land plants live in symbiosis with soil fungi (mycorrhiza) to absorb water and nutrients more efficiently. In addition, a number of types of microorganisms settle around the roots, which feed on their excretions and in return release nutrient ions from the soil for the plant. These two examples show that soil is more than just a sponge for water and nutrients.

Of course, mineral fertilization is still possible. However, since it makes a number of biological processes in the soil superfluous and chemically out of balance brings, is a deterioration of the soil quality with sole mineral fertilization unavoidable. Mineral fertilization is particularly unsuitable for hydrangeas: they need a flowing and Needs-based nutrient supply to develop frost-tolerant shoots and lots of humus to meet their water needs cover up. Both are included organic fertilization much easier to achieve because it relies on the natural regulatory processes of the "soil organism".

Fertilize hydrangeas with home remedies

As already mentioned, hydrangeas love an acidic location. For example, composted oak leaves, grape pomace and coniferous earth are suitable for maintaining the acidic soil environment - i.e. the earth that is found under coniferous trees. It is also possible to mulch the soil under hydrangeas with a mixture of oak leaves, pine shavings and something horn mealto stimulate the decomposition and release of acids. A mixture of chopped oak leaves, moist coffee grounds, pine wood shavings and needles and some horn meal is also effective. In order to determine the need for such an application, it is always advisable to test the pH of the soil beforehand. This is possible with a commercially available test kit or in the course of a soil analysis.

The usage of horn shavings or horn meal as the sole fertilizer is not recommended, as these mainly contain nitrogen and phosphorus, but hardly any potassium. A small dose in spring, for example in connection with an acidifying mulch layer, can definitely be beneficial - but it should always be supplemented with a full-fledged fertiliser.

tip: The Mulching hydrangeas offers some advantages, which we have compiled in our special article.

Identify nutrient deficiencies in hydrangeas

Below we summarize common deficiency symptoms in hydrangeas and how you can recognize them.

Iron deficiency in hydrangeas

The symptoms of iron deficiency are intercostal chlorosis (yellowing of the leaf, the leaf veins remain green for a long time) on the youngest leaves. Iron is a micronutrient that is most readily available to plants when soil pH is low. Since the iron uptake strategy of hydrangeas is set to a low pH value, they quickly suffer from an iron deficiency if the soil is not acidic enough. Unlike some other plants, they simply do not manage to absorb it efficiently. The safest way to lower the soil pH value is to combine it with iron fertilization. Our Plantura organic hydrangea fertilizer therefore contains a small amount of iron to rule out an absolute deficiency from the outset. More detailed information about Iron deficiency in hydrangeas can be found in our special article.

Nitrogen deficiency in hydrangeas

The symptoms of nitrogen deficiency are chlorosis (yellowing of the leaf) on the oldest leaves. Nitrogen is “mobile” in the plant, so it can be moved. When there is a shortage, nitrogen is sent from the old, less important leaves to the youngest leaves. Nitrogen fertilization eliminates the deficiency, of the organic fertilisers, the liquid variants work the fastest.

Potassium deficiency in hydrangeas

A potassium deficiency shows itself in the form of the so-called "wilting", the foliage looks limp, despite an adequate water supply. Later, necrosis forms, starting from the leaf edges and tips. All symptoms appear first on the older leaves. A potassium deficiency can promote frost damage in winter. A fertilization with potassium fertilizer usually rectifies the defect quickly. However, it is important not to be overly frugal. Potassium is required by plants in large quantities and the storage locations in the soil should always be well stocked. Our Plantura organic hydrangea fertilizer contains enough potassium to effectively prevent a deficiency.

If you want to learn more about why special hydrangea fertilizer are necessary, you will find all important information here.