Bare-root and root-balled shrubs are best to be planted from autumn to spring, in their dormant period. Container-grown shrubs can be planted at any time of the year but for best results is good to plant them also in their dormant period. Autumn planting allows the root system to establish well while the soil is still warm. Planting can continue over the winter period but only when the weather is mild and the soil is not frozen else the roots will not grow and there is a risk that they may freeze and get killed.
To give a good start in their long life you must prepare well the planting site before planting your shrubs. Prepare the site starting from late summer or early autumn by removing or killing all the weeds, double dig and incorporate a layer of about 10 cm of well-rotted organic matter into the lower trench. You can also add fertilizers if you think is necessary.
The plating hole for your shrub should be big enough so that the root ball have enough space to fit in. If you are planting bare-root shrubs consider the planting hole as large as the roots can be spread out fully or if you are planting container-grown or root-balled shrubs the hole should be twice the width of the contained root mass. The hole must also be deep enough so the shrub will be planted at the same level as it was in its container or in the open ground.
For better results you can add some more organic matter into the planting hole and mixed with the removed soil. If planting a container-grown shrub take it out carefully from its container and tease out the root system. For root-balled shrubs remove the hessian or netting from the roots after you put the shrub in its hole. Use a can to lay it down across the top of the planting hole to guide you to the depth of planting. Backfill the hole with removed soil and organic matter mixture. If planting a bare-root shrub just shake it gently while you backfill so the the soil settle between the roots. Firm the soil in stages to prevent the forming of air pockets. After you finished to fill the hole, firm the soil around the shrub with your heel or hands.
If you see any diseased or damaged wood now is time to prune it back to healthy growth and also to remove any very long, weak or straggly stems or the ones that spoil the overall balance of the shrub’s framework. Water the shrub thoroughly and apply a mulch of well-rotted compost to keep the moisture and prevent the roots to freeze.
Hibiscus syriacus, the common garden Hibiscus, also called Rose of Sharon or Rose of Althea is a woody perennial, deciduous, flowering shrub that can reach 2-4 m in height. It is widely planted in areas with hot summers for its very attractive white, pink, red, lavender, or purple flowers. The flowers are large, solitary, showy, single or double and appear from mid summer to early autumn on current season's growth. Since plants bloom on new growth, shaping or pruning can be done at any time; prune in late winter or early spring in northern climates. The flowers only open in sunny weather. The flowers are hermaphrodite (have both male and female organs) and are pollinated by insects attracted by flat blossoms and nectar.
Native to India and East Asia, the national flower of Korea, it is the perfect shrub for groupings and mass plantings, to create a screen, or planted as a formal or informal hedge or in a shrub border. Standard forms may be used as small trees planted to the entranceways. It has a medium growth rate, with a narrow vase-shaped to arching growth habit, often becoming arching with age if never pruned.