The best time to plant a shrub used to be autumn – with a few exceptions. Many writers will say anytime is ok for a container-grown shrub, and garden centres will agree, because it gives them ‘all year trade’. But the subject of when to plant a shrub is dependent upon several features
There is a strong case for autumn planting of shrubs and many other hardy plants, but there is also a case to be made for year-round planting as well. Much depends upon the variety of shrub, and more importantly, how that shrub was grown at the nursery before it reached point of sale.
The main argument against autumn planting is the fact that shrubs are now grown for sale in a different way to how they were decade or so ago. Nowadays, many shrubs are container grown at least for the final stages of preparation, either partly or wholly under cover of polythene or at least with some form of protection from the elements. This allows shrubs to be produced much quicker from the initial propagation stage right through to the selling stage.
Compared to the traditional field growing, shrubs nowadays are molly-coddled into pristine condition by protective growing conditions. The growth – particularly the younger stems – may well have developed in recent months - forced by tunnel and glass house rearing - instead of the gradual growth and ripening process that is normal when grown in the open.
Don’t forget that your garden shrub is going to spend its life facing the elements of winter – and summer! It is not going to have the comfort of a polythene tunnel.
Retail marketing is now essential for gardening businesses to thrive, and that means displaying a product that visually appeals to the customer. This is normally glossy, unspoiled foliage – preferably with a few flowers in evidence.
Add to this the fact that most are now mostly fair-weather gardeners - and buyers - and you will soon realise why this change of emphasis into spring and summer planting has developed over the years.
When shrubs and other hardy plants were field-grown in the open, they could only be successfully lifted and planted in autumn or sometimes through the early winter. Spring is not a good time to plant bare-root shrubs or even those with a wrapping of hessian to hold some soil in place.
When to Plant Shrubs
Container-grown shrubs can be theoretically – and with proper care -
planted at any time of the year but midsummer or even early spring are
fraught with re-establishment problems. But they are problems that can
Bear in mind, that during the spring months, the air temperatures warm up far quicker than soil temperatures. The soil has probably had four or five months of cold – sometimes freezing – temperatures and this cold has reached well down into the top soil (our planting soil!).
It will take rather more than a few bright sunny days for the soil to warm up – maybe a month or so. Planting this time of years invariably means that the growth above ground – the foliage – will start to break and grow before the roots have established themselves in their new home. At this time, the plant will need moisture and food to enable good establishment. The restricted root system will not have enough time to grow the new roots required to provide either. Watering regularly will be required – unless steady rain – and this should be in the centre of the root-ball as well as the surrounding soil area.
Nevertheless, spring is often the best choice for shrubs of a slightly tender nature – and especially most climbers. (Climbers are normally grown in protected environment at the nursery – even if only surrounded by windbreak material to keep them upright in the nursery rows! Late autumn planting will invariably mean planting a shrub which has been grown in ‘soft’ protected conditions!)
Many shrubs are at their best during May through June and are essential ‘impulse’ purchases – often full of flower, and with well fed and nourished foliage. A garden center’s blessing, and these quickly move off the shelves and beds.
In these months, the soil will have warmed up for the newly planted root system – but so will the air temperature and growth of the shrub - ideal growing conditions in a natural environment.
The main problem to overcome is the fact that the root system of our
container grown shrub will severely restricted by the size of the pot.
As a rough guide only, the root system of a growing shrub will normally
be at least out to the perimeter of the branches foliage canopy. Extra
care will be needed to ensure adequate water is available – deep down
into the roots - and possibly ‘shading’ the shrub for a few weeks until
established. Summer is not the best time to
plant a shrub - but it can be successful.
Summer is not the best time to plant a shrub - but it can be successful.
This time is the best time to plant defoliated bare root shrubs – roses in particular – as they can be planted whilst the soil is still warm; growth above ground will have slowed right down – even stopped; additional watering is rarely required, for the reasons of natural rainfall; generally moist soils and a less need for water and food as the plant goes dormant.
Root growth continues even after the plant has defoliated as the roots seek to stabilize and reach out ready to support the growth of the plant after winter has receded.
Important to ensure the shrub is well supported to avoid rocking back and forth in the winter winds. This rocking movement normally transfers below ground unsettling the establishment of the new roots.
Winter planting should only be carried out if you have to and certainly not when the soil is frozen. Bare root and hardier shrubs such as roses can be planted if the soil condition is suitable – not wet and soggy as with most heavy or clay soils.
If you are up to it at this time of year, it is a feasible option for bare root and field grown shrubs such as hedging plants.
Evergreens should NOT be planted in winter as they will have a foliage canopy which will release moisture quicker than the new roots can supply – especially in drying winds. Wind is one of the biggest drawbacks of winter planting, and if prolonged can soon lead to the desiccation of even deciduous shrubs.