Regular fertilization is essential in order to avoid light leaf cover, growth disorders, leaf discoloration or even box hedges shrinking. But be careful, because the wrong fertilizer and / or too high or too low fertilizer doses can damage the box tree instead of having a positive effect on it. For this reason, it is important to do your research on fertilizing boxwood.
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If the soil conditions are optimal and there are no heavy consumers in the immediate vicinity of box trees (Buxaceae), the nutrient requirement is quite low. But with box tree hedges, the hobby gardener usually depends on them growing tightly in order to act as a privacy screen or to achieve a harmonious look. Due to the otherwise slow growing book, fertilizer supports stronger growth. For this purpose, a fertilizer should be used that is precisely tailored to the needs of box hedges. Mainly the following components are required for this and should be combined with one another:
- Nitrogen for improved, stronger growth
- Iron to form chlorophyll
- Magnesium promotes the formation of chlorophyll
- Phosphorus as an energy source, but only in small quantities, since box trees do not need any other properties for blossoming and fruiting
- Zinc also supports growth
The best time to fertilize
While a Buxus rests in winter, it slowly begins the growth phase again in early spring from April. From this moment on, the nutritional requirement increases rapidly. Frost can still limit the supply of required nutrients in the soil at this time of the year or limit the availability. For the box tree this means that it cannot “start” properly at the beginning of the natural growing season. If the right fertilizer is administered in March / April, which gets deep into the soil to the root ends, nothing stands in the way of a strong start of growth.
How often box hedges should be fertilized depends on the fertilizer. This is where the differences lie in the short-term and long-term effects.
Some short-term fertilizers are given once a week, others only once a month. Long-term fertilizers, on the other hand, usually last a few months, so that fertilizing is only necessary in March / April and a second time in August / September.
Last fertilization of the year
The last fertilization should not be later than the beginning of September. Otherwise, the Buxus would form new shoots that would freeze to death in winter due to the lack of frost resistance. This can damage box hedges as a whole, because frozen parts of the plant significantly increase the risk of infections and pests. Many hobby gardeners therefore fertilize their box tree for the last time in the gardening season in mid-August.
Under certain conditions, box trees can suffer from deficiency symptoms. This happens, for example, if, for whatever reason, the soil conditions change or the uptake of nutrients is disturbed by, for example, root rot. Of course, the cause must be clarified and remedied in advance, provided that it is not simply a matter of missing fertilizers. Too low fertilizer doses also provoke deficiency symptoms. If the box hedge is not growing properly, this is often due to a nitrogen deficiency. The leaves turn reddish or bronze in color.
If you want to get a weak or young boxwood plant through the winter better, you can fertilize with a special potassium fertilizer. The best time is between the end of August and mid-October at the latest.
Fertilizer for strong growth
In order to be able to grow unrestrictedly in spring, a box tree has to get through the winter undamaged. Ever lower winter temperatures do not make it easy for him, even if he is quite hardy. He gets strength and endurance with a potassium fertilizer, which is offered as patent potash or potash magnesia. This promotes rapid lignification of the shoots so that frostbite does not occur. In addition, the potassium fertilizer increases the frost resistance.
Fertilizer from the specialist trade
For the growing season of box hedges, the market offers a wide range of chemical and organic products especially for green plants and box trees. These range from liquid fertilizers to fertilizer sticks to granular fertilizers. Box tree fertilizer, which can usually be used for other evergreen plants, contains a lot of nitrogen and potassium. Phosphorus is present in small amounts. You can choose between short-term and long-term fertilizers. Some proven products are for example:
Cuxin boxwood fertilizer
- Optionally available as liquid fertilizer or granules
- Slow release fertilizer
- Fertilizer rhythm: March / April and August / September
Compo boxwood fertilizer
- Long-term mineral fertilizer
- Fertilization: once in March / April
- Use as a liquid fertilizer every four weeks
Mairol Buchsbaumpracht Liquid
- Liquid fertilizer for pouring
- Contains all important nutrients plus zinc
- Short term fertilizer
- Fertilization: every two weeks
For better environmental compatibility, you can also rely on natural fertilizers. Some of the products listed below are already available as waste products in many gardens and households.
Horn shavings are available as artificial fertilizers in specialist plant shops, but they can also be produced from hoof horn residues if they are produced during cutting on a farm or riding stables, for example. These are cut into small pieces of horn. If horn is finely ground, the result is horn meal, which is equally suitable for fertilizing box hedges. Horn shavings and horn meal ensure long-term fertilization and should be used as fertilizer in early spring and July / August.
Depending on the product, the boxwood benefits from the following components:
- Twelve to 15 percent nitrogen
- Potassium up to one percent
- Phosphorus under one percent
Long-term fertilization with compost can be achieved if rotted, dried compost is worked into the soil at the beginning of the growth phase. The best time for the second fertilization is before the beginning of autumn.
Fresh, moist compost is suitable to remedy deficiency symptoms. This releases its ingredients directly so that they are available and can be immediately absorbed by a box tree. Fertilizing should be done every three to four weeks. It is advisable to always incorporate fresh compost into new and transplanted plants. A fertilizer break must be observed after six weeks.
It is fertilized by removing a little soil from the surface around the boxwood, mixing it with the compost and then backfilling the enriched soil. It is important to mix the compost evenly with the earth. The deeper the compost gets into the ground, the better it can act as a fertilizer.
Ingredients of compost
- more potassium than nitrogen
- as much phosphorus as magnesium
Blue corn is a partially suitable fertilizer. Recommended by hobby gardeners as an addition to the warmest compost, but due to its relatively high phosphorus content, it is almost a waste to use it for fertilizing box hedges.
However, blue grain is rich in the nutrients that a box tree needs. It contains a large amount of nitrogen, potassium and magnesium. However, the content of the nutrients differs immensely. The branded product “Nitrophoska” has the following values, for example, which, with the exception of the phosphorus content, optimally meet the requirements of a Buxus:
- 20 percent potassium
- 15 percent nitrate or nitrogen
- Eight percent sulfur
- Five percent phosphate
- Two percent magnesium
Coffee grounds are a great alternative to traditional fertilizers. The home remedy is tried and tested and is praised by numerous hobby gardeners as a fertilizer for box trees. But supplying an entire box hedge with enough coffee grounds becomes difficult if the coffee machine is not running all day.
For shorter box hedges, coffee grounds can still be very helpful as a short-term fertilizer. Above all, it contains nitrogen and potassium, which support vigorous growth and ensure lush green leaves.
Coffee grounds are prepared and used as follows:
- Spread out the coffee grounds flat and allow to dry
- Distribute the dried coffee grounds evenly on the surface of the ground around the boxwood
- Work the coffee grounds into the soil with a coarse rake
- Fertilizer rhythm: once a week
For strong growth, dense foliage and healthy thriving, box hedges must be fertilized. There are numerous fertilizers to choose from, of which the ones mentioned here have proven to be effective. Basically, with all fertilizers, less is usually more, so that over-fertilization, which is harmful to plants, is avoided.