Many garden owners will probably not fertilize their lilacs, but will rather rub their eyes in surprise at this question. In fact, it can be very useful to provide even planted lilac bushes with additional nutrients. You can find out why this is the case and how best to proceed in the article below.
How do you fertilize lilacs correctly?
To properly fertilize lilacs, provide the plant with organic fertilizers containing potassium and phosphorus such as compost, horn shavings, manure or special flowering plant fertilizer in spring and, if necessary, in June. Avoid nitrogen-rich fertilizers as they inhibit flower growth.
Do you even have to fertilize planted lilacs?
Basically, you don't “have to” fertilize your garden lilacs. However, if it has been in its location for a few years and you have perhaps already been surprised by the dwindling blooms, then the cause could be a lack of essential nutrients. If the lilac suffers from a nutrient deficiency, it no longer has enough strength to produce flowers - and at some point it may no longer bloom at all. Lilacs in locations with very poor soil also benefit from fertilizer application.
When is it best to fertilize?
Both planted and potted lilacs are fertilized for the first time in early spring, shortly before budding. Depending on the nature of the soil, this may be sufficient as long as the soil is rather nutrient-rich. If, on the other hand, the subsoil is rather sandy and poor, you can care for the lilac again in June.
Since lilacs (with the exception of the Preston lilac) prefer to grow in calcareous soil, the pH value of the soil should be between 5.5 and 7. If it is lower, fertilize the plant once a year with a lime-based fertilizer. Work this carefully into the top layer of soil.
First fertilization during planting
However, the lilac receives its first fertilization when it is planted. Here you mix the excavated material with plenty of compost and a generous handful of horn shavings. The natural fertilizer acts as a boost for he althy growth and provides the plant with all the nutrients it needs for successful growth.
Fertilize planted lilacs properly
Whether and how you should fertilize your planted lilacs depends on the specific soil conditions in your garden. The leaner it is, the more frequently fertilization must be carried out. If possible, use an organic, slow-acting fertilizer with high levels of potassium and phosphorus. There should only be a little nitrogen in it, because this acts as a growth booster with the result that the lilac grows very quickly and produces many shoots - but no flowers.
Which fertilizers are suitable for feeding lilacs?
Organic fertilizers are completely sufficient for the supply of nutrients and also have the advantage that they do not seep into the groundwater. The following are particularly suitable for lilacs:
- ripe compost
- Horn shavings or horn meal
- Stable manure (preferably horse manure, but not poultry manure! This is very high in nitrogen.)
- homemade decoction of nettles and horsetail
Alternatively, you can also supply the lilac with blue corn (€34.00 on Amazon) (be careful, only use a little!) or a commercially available fertilizer for flowering trees.
Tip
Lilacs in pots should be placed in fresh substrate about every two years and, if necessary, in a larger pot. Otherwise, fertilize with a liquid flowering plant fertilizer about every two weeks between April and September.