Hello. First of all, you should bear in mind that in general, large plants are more difficult to adapt after planting and success is not guaranteed (Ornamental trees and shrubs - Planting guide). To stimulate the development of roots, you can consider using a fertilizer with beneficial micro-organisms in its composition, which at the same time contributes to improving the quality of the soil: , or , by watering at the roots, in the dosage recommended in the description of the chosen product. At each application a volume of prepared solution (water + fertilizer) equal to the amount of water that is normally used for watering is applied.
It is also recommended to regularly apply a foliar fertilizer that is specially formulated for the nutritional requirements of conifers: , by foliar spraying, according to the instructions on the label. This fertilizer supports the plants’ resistance to stress factors, increases foliage density and helps prevent deficiencies and yellowing/browning of leaves. More information on this topic can be found on our website: Thuja, planting guide and care work.
In the case of magnolias, to stimulate a vigorous growth, you can consider the regular administration of one of the root fertilizers recommended above. If you also want to use a foliar fertilizer, you can take into account the product (20-30 ml/10 L water) or (20-60 ml/10 L water), according to the instructions in the description of the chosen product. More information on the care of this plant species can be found in our article: Magnolia, planting guide and care work.