Laburnum: planting, care & pruning
Planting laburnum is not difficult and caring for the beautiful ornamental shrub is also easy.
With its long, golden-yellow flower clusters, laburnum (Laburnum spec.) is a visual highlight for every landscape and private garden. However, if you want to put the plant in your garden, you should be aware that laburnum is poisonous. In this article, you will learn more about planting and pruning laburnum, among other things.
Contents
Planting laburnum
As laburnum is not particularly demanding of the soil in which it is planted, not much can go wrong. You will need to be quite sure about the chosen spot, however, as laburnum does not tolerate transplanting well.
The right location
The most suitable spot for laburnum is a warm location, which should be sunny to semi-shady. In winter, a sheltered spot in particular can contribute to the vitality of this woody plant. Laburnum prefers to grow in moderately dry to fresh, well-drained and light garden soil.
It is therefore worthwhile improving your garden soil if it is heavy and compacted. The soil should be deeply loosened and mixed with sand to a volume of at least 30 % to ensure the required permeability. As laburnum is often found in more calcareous soils, it can be helpful to enrich the garden soil with some lime if there is not enough already.
To create the optimal starting situation for laburnum, the pH value and the soil quality should be determined before soil improvement. The optimum soil pH for laburnum is in the range of 6.5 to 8. It should be noted that undemanding laburnum can also cope with soils that are not optimally adapted.
Can laburnum be cultivated in a pot? It is possible to cultivate the laburnum in a container, but it is much more demanding and time-consuming to care for and overwinter than growing it outdoors. Furthermore, it should not be underestimated how tall the laburnum can grow. In that case, cultivation as a bonsai might be an interesting alternative.
Plant laburnum: instructions
Planting outdoors:
- Best time of year: spring
- Dig a hole twice the size of the root ball
- Improve soil if necessary
- Plant laburnum with soil ball at ground level
- Press down the soil and water
Container planting:
- Choose a planter with a large diameter and drainage for water
- Fill the bottom of the container with a drainage layer of expanded clay of 3cm
- Fill with a permeable, high-quality substrate that has been mixed with at least 30 % sand
- Water thoroughly
Tip: unlike laburnum planted outdoors, when this woody plant is grown in a container, it needs winter protection so that the roots are not damaged. Alternatively, it can be overwintered in a bright, frost-free room.
Caring for laburnum
Caring for laburnum planted outdoors is very easy but a few things still need to be kept in mind to ensure the optimal well-being of this woody plant. As already mentioned, specimens planted in tubs require considerably more attention.
Watering and fertilising
Once the laburnum is well established in the garden, it can survive even dry periods in summer. However, if these persist for a longer period of time and the soil dries out completely, you should definitely give it a helping hand and thoroughly moisten the subsoil again. The only thing that must be avoided is waterlogging, as laburnum does not tolerate this.
In the tub, on the other hand, you will need to use the watering can or garden hose regularly. The substrate should always be slightly fresh so that the laburnum feels comfortable.
This woody plant does not have particularly high nutrient requirements, which is why it likes to grow in soils that are low to moderately high in nitrogen. Applying compost in spring should therefore be sufficient fertiliser. As the substrate used for container planting in most cases already contains some nutrients, this does not need to be upgraded until the following spring. A compost soil can be used for this purpose, which is mixed in with the old substrate. Our peat-free Plantura Organic Enriched Compost, for example, with its pH value of 6.9 and its high proportion of phosphate and potassium for flower formation, provides a good basis for laburnum.
- Perfect for all crops and ornamental plants with a high nutrient requirement & for raised beds
- Improves soil quality & promotes healthy root growth
- Peat-free & organic soil: CO2-saving composition
Did you know? Because laburnum belongs to the Papilionaceae family (Faboideae), it is able to form a symbiosis with the so-called nodule bacteria, through which nitrogen is fixed in the soil.
Pruning laburnum
Because of its naturally beautiful growth habit, it is not really necessary to prune laburnum. Pruning can nonetheless be very important, especially for container-grown specimens or less spacious planting sites, to keep the size of laburnum in check. A suitable time for this is early summer after flowering has finished.
Laburnum not flowering: what to do?
The simplest explanation for the absence of flowering of the laburnum is the age of the plant. If the laburnum was grown from seed, it takes about 5 to 10 years to flower. Plants that have been propagated with cuttings only need about 3 to 5 years. The location may also cause the laburnum not to flower, but it would have to be very unsuitable for that to happen. This could mean that the soil is too heavy or extremely compacted or that the site is in heavy shade, for example. In this situation, a change of location and soil upgrading is appropriate.
Lupin (Lupinus spec.) is also a member of the Papilionaceae family and plays an important role in green manuring, among other things. Depending on the species and variety, it is also a valuable food source and is valued as an ornamental plant because of its unique flowering.
