Plant containers are certainly a valuable aid when it comes to potting hedge plants if you don’t have access to a garden or patch of earth. You can recreate the screening effect of a hedge by planting a closely spaced straight or curved row which will allow the branches of the plant to knit together. Believe it or not, many hedging plants will happily grow in a container, and in this article, we will talk you through everything you need to know in order for your hedge plants to flourish. First things first though, you have decided on your container…
SECTION 1: CHOOSING YOUR CONTAINER
Containers come in all shapes and sizes, and each come with their own advantages and disadvantages, however, the only thing you must ensure is that your container has drainage holes. We also recommend you keep the pot dry in winter to avoid cracks from occurring. With that being said, let’s have a look at your options…
Clay and Terracotta
- Traditional material that suits every garden style
- Prone to cracking in frosty conditions
- Can dry out quicker in the spring and summer so may require more frequent watering in the sunshine
- Always choose frost-proof pots
- Protect them in winter by wrapping in bubble-wrap, sacking, or a similar material
- Stand them on feet and remove saucers in winter to prevent waterlogging
- Move them to a more sheltered spot for winter or don’t place in an over-exposed area to begin with
- Check the compost regularly in the summer and water if dry
- Can be easily moved as they are lighter than clay or terracotta
- Retains moisture better so less watering may be required
- The variety of plastic pots means you can easily find one to suit your requirements
- A popular choice for a modern style garden (we always recommend choosing a galvanised or other rust-proof metal)
- Will retain moisture in the summer
- If placed in direct sunlight the material can overheat
- Can get colder in the winter so should be protected with bubble wrap and/or sacking
- Won’t crack in the winter
- Retains moisture in the summer
- As wood is a natural material it will eventually rot
- Add a wood preservative to increase the lifespan
- Raise the wooden container to prevent premature rotting
- Make sure you select a plastic lining (again, remember to add holes in the bottom for drainage)
- Using the traditional half-barrel (especially with a lining), though the metal hoops can rust. It is therefore worthwhile painting the hoops carefully with a weather proof paint or other coating
- Attractive design
- Retains moisture reasonably well
- Can be heavy
- Choose only frost resistant containers and protect in winter
- Have become an increasingly popular option as a garden container
- Provide more than enough depth
- When filled they are extremely difficult to move
- Lack of colours and varieties
- Remember to puncture the base with at least a dozen drainage holes
- Use gravel to avoid puncturing the bag
- Put 10-15 cm of garden waste and compost on top of the gravel before filling with compost
What about the Size of the Pot?
Now we’ve provided a breakdown of your container options, it’s now time to think about the size. We recommend that you start with containers large enough to take the roots with 6-8cm spare at the widest point. This will encourage the plant to grow stronger and you will not need to repot into a larger container for around 2-3 years.
SECTION 2: PLANTING AND AFTERCARE
The majority of hedge plants will be fine in a loam-based compost, such as John Innes No. 3 or similar. First though, you must add some broken crocks and/or gravel at the base to a depth of at least 5cm. This is essential to support good drainage. In larger pots a good layer of garden compost or waste can also be added.
If you are using proprietary compost you will not need to add any fertiliser for 4-8 weeks (see the packaging for specific details). In spring, once the fertilizer in the compost has run out, add a general purpose, slow-release granular feed according to the pack instructions. Nitrogen is a key nutrient for growth, but it’s important to not overfeed. Organic granular feeds are also available. There should be no need to feed from late summer to the end of winter.
At the beginning of their second spring, top dress the containers by carefully removing around 5cm of the compost and replacing it with fresh, mixing in fertiliser granules as above.
Although some containers do an okay job at retaining moisture, hedge plants in containers tend to dry out far more quickly in hot winds than if they were planted in the earth itself. It is important to remember that the plant’s own foliage can prevent rain from reaching its soil, so don’t assume that if it has rained, your plants have been watered. The compost should always be moist, but not sodden – even during winter when the wind can dry it out. From April to September, you should, ideally, check containers daily, especially during hot weather. Watering, whether with hose or can, should be done twice, filling the container to the brim and allow the water to filter down. Then repeat. This is the best way to ensure all of the compost has been wetted. If the water is not draining freely, check the drainage holes and unblock as required. Mulching will help deter weeds and moss but will only have a minimal effect on water retention. In exposed gardens, plants in containers will need protecting during winter as the roots growing near the edges are vulnerable to freezing temperatures. Wrap the container with bubble wrap or hessian, held securely in place with twine.
BUT: Evergreens (Box, Yew, Leylandii etc.) may need watering in winter, especially if they are in a well-protected spot.
In winter you have to be particularly careful of frost and waterlogging. Smaller containers will be more at risk in the colder weather so it’s important to take the right preventative measures. Wrap containers in bubble wrap or sacking, or alternatively, move to a more sheltered spot, raise, and remove saucers.
Hedging plants can grow strongly in cramped conditions, producing better foliage as an end result if properly cared for. However, after 2-3 years the plant may need to be transplanted to a larger container or provided with fresh compost, which helps to avoid the threat of adverse weather, pests and diseases.
How to re-pot your plants:
- Re-pot in early spring as soon as there are signs of new growth
- Remove a little of the compost, tease out the plant and its roots – don’t be afraid of cutting the roots if necessary
- Use fresh crocks and/or gravel to prevent transferring any disease that may be present
- Replant in fresh compost
- Once your plant is in the optimum size container, replace the compost every other year – in extremely large containers, simply replace at least one third of the compost every other year
SECTION 3: PLANTS THAT GROW WELL IN CONTAINERS
- Beech (Fagus sylvatica): One of our most popular trees that still grows very well in containers
- Box (Buxus): Box Balls, and Pyramids make excellent container plants, adding structure and a sense of simple formality to a garden. Often used in pairs or rows either side of a door or bed
- Dwarf Box (Buxus sempervirens ‘Suffruticosa’) makes a perfect container centrepiece for companion planting with annuals, low-growing herbs or dwarf Lavender
- Escallonia macrantha Rubra ‘Crimson Spire’: Will need repotting sooner than most – but worth it for decorative glossy foliage and a dark red floral display that lasts from summer through autumn.
- Euonymus fortunei ‘Emerald ‘n’ Gold’: This dwarf evergreen with green and yellow-gold foliage looks great in a smaller container
- Euonymus fortunei ‘Emerald Gaiety’: More subtly variegated than its cousin above, Emerald Gaiety makes an elegant and bushy container shrub
- Hornbeam (Carpinus betulus): Like Beech, the Hornbeam makes a superlative container-grown focal point
- Cherry Laurel (Prunus laurocerasus ‘Rotundifolia’): As robust as it is attractive, the container-grown Laurel may need a stake or two to keep its shape
- Leylandii (Cupressocyparis Leylandii): The Leylandii’s growth can easily be kept in check when planted in a container
- Perovskia Blue Spire (Perovskia atriplicifolia ‘Blue Spire’): Although not normally grown in containers, if this is the only way you can get this stunning plant into your garden, take it. As it looks its best in a clump, choose a medium to large container and plant five or more as space allows. Even better, take a larger container, surround a central clump with dwarf lavenders – one of the great horticultural pairings
- Photinia Red Robin (Photinia x fraseri ‘Red Robin’): The choice for a vibrant splash of red.
- Privet ( Ligustrum vulgare): Faster growing than Box, container-grown Privet is best when shaped and is the plant of choice for first-time topiarists
- Purple Copper Beech (Fagus sylvatica ‘Purpurea’): The showiest of the Beeches is perfectly at home in a container. However, we recommend the plant remains exposed to the sun in order to maintain its beautiful colour – failure to do so will result in colour loss.
- Yew (Taxus baccata): Like the Beech above, Yew too will grow well in a container (Yew Trough). We thing every garden can, and should, have a Yew.