Elizabeth is a Permaculture Garden Designer, Sustainability Consultant and Professional Writer, working as an advocate for positive change. She graduated from the University of St. Andrews with an MA in English and Philosophy and obtained a Diploma in Applied Permaculture Design from the Permaculture Association.
Reviewed By ROY NICOL
Roy is a Professional Gardener and Horticultural Consultant, specialising in large garden year-round maintenance and garden development. He is an RHS Master of Horticulture and uses his research in the application of no-dig methods in ornamental garden settings. Roy has been a Professional Gardener for more than six years and is a member of the Chartered Institute of Horticulture, Professional Gardener's Guild and Association of Professional Landscapers (Professional Gardener).
IN THIS GUIDE
Astilbes are vibrant, hardy perennials which love moist conditions and can thrive in sun or partial shade.
They can be a great choice for many different gardens, but if you only have space for containers, then you may be wondering how to grow Astilbe in pots.
Can Astilbe Be Grown In Pots?
The good news is that Astilbes can certainly be suited to container growing, though when choosing which cultivar to grow, it is important to look for smaller varieties.
Some Astilbes will grow rather tall to 120cm in height and can have a spread of up to 1m or more, but there is a range of smaller Astilbe which are more suited to container growing.
Most dwarf Astilbes are hybrid types, often with A. simplicifolia as one of their parents, sometimes a descendent of A. chinensis.
Dwarf types will be under 60cm in height, with a similar spread.
Some cultivars well suited to container growing include:
- ‘Bonn’
- ‘Bronce Elegans’
- ‘Europa’
- ‘Hennie Graafland’
- ‘Maggie Daley’
- ‘Mainz’
- ‘Rheinland’
- ‘Serenade’
- ‘Sprite’
- ‘Willie Buchanan’
Choosing A Container
One of the key things to think about, of course, when you wish to grow Astilbes in pots is which sort of container you should choose, and what size it ought to be.
When choosing the type of container, and thinking about what it is made from, remember that Astilbe needs moist conditions, so try to choose a container which does not lose water too quickly.
“Terracotta pots are porous and loose moisture relatively quickly, so other materials such as recycled plastic, ceramic or fibreglass should be considered,” says Roy Nicol, Master Horticulturist and Professional Gardener.
“Fibreclay made from resin, mesh and clay is another good option, as it is sustainable (using waste outputs from other industries), light and strong.”
While they like moist conditions, they do not like excessive waterlogging, so make sure the container you choose has suitable drainage holes at the base.
Typically, single Astilbes are grown in pots around 40cm in diameter, with a depth of at least 30cm.
Choosing Potting Medium
Since Astilbe like moist conditions, and a rich environment, make sure that you fill your container with peat-free multi-purpose compost, or a homemade equivalent, and add some homemade compost or other organic matter for an extra nutrient boost.
Mulch around the plant in the top of the container with more compost, or another organic mulch.
This will help to retain moisture and also provide slow-release nutrients over time.
Potting Up Astilbe
Astilbe typically need to be potted up into newly filled containers every 3-4 years.
Choose a slightly larger container each time or, when this is no longer practicable, consider dividing your mature plant and repotting each division in its own individual pot.
How Many Can You Plant Per Pot?
If you have a larger container, you can plant more than one Astilbe in it.
When deciding how many Astilbes you can plant per pot, it may be helpful to keep this spacing guide in mind as a rough rule of thumb:
- Seedlings can be sown and thinned to their eventual spacing when they are around 5-7.5cm tall.
- Small Astilbes can be planted around 15-20cm apart.
- Larger Astilbes can be planted around 20-30cm apart.
Remember, Astilbe can also be planted in larger containers with other plants which like similar growing conditions.
For example, you might plant Astilbe with Primulas, Hostas and Heucheras.
Just take care to avoid overcrowding.
Choosing larger containers can be a good idea when growing Astilbe and other shade-tolerant, moisture-loving plants.
Remember, the larger the container, the more moisture it will retain and the less frequently you are likely to need to water.
Container Growing Care
Place the pots in a partially shaded spot.
However, you should not place your container in deep shade, or the plants will not flower at their best.
The most important thing when growing Astilbe in containers is to make sure that the plants are well watered, and that the growing medium stays moist at all times.
You should check container-grown plants daily to make sure they do not dry out.
Use rainwater whenever possible, and try to water deeply rather than little and often.
There is no need to feed Astilbe, just make sure that you grow them in a suitably nutrient-rich potting mix and replenish the organic mulch around the plants each year in spring to provide these plants with the nutrients they need.
Leave faded flowers in place for an attractive autumn and winter display.
Then, cut back all old growth down to the ground level in the winter before new growth appears in early spring.
