Saturday 3 October 2015

Container Gardening with
Harriet Rycroft, week 3


I always knew that the third week of this course was where I’d begin to find things a little more challenging – in fact, this tutorial was one of the main selling points of the course for me. We’ve been looking at planting containers for winter and spring interest, something I’ve never had trouble with in the past, but largely because I use a far less sophisticated approach. Typically, I’ll create containers for autumn and winter, using plants with interesting evergreen foliage and impressive berries to create the backbone of any display for several months, around which pots of more short-lived seasonal colour can be introduced – cyclamen before Christmas, tulips, narcissi and hyacinths later in the new year.

This modular modus operandi is reasonably foolproof, having the advantage that, as long as you get the main plants right, you can tweak by moving the smaller pots about, removing anything that isn’t performing quite as well as you’d hoped, and perhaps redistributing containers to draw attention to a particularly pleasing element. It allows both for serendipitous discovery, and wiggle room, and I’d be happy to recommend this way of working on these grounds alone, if it wasn’t for the fact that it’s more or less how the wonderful displays in the porch at Great Dixter are put together. And if it’s good enough for Dixter, it should really be good enough for anyone.

That said, there is another way to plant in containers – and, happily, it can be used alongside such a modular approach as I’ve become used to. The only slight fly in the ointment is that it’s a little more involved, requiring both more planning, as the planting needs to present interest over a longer period of time,  as well as a good deal more commitment, there being less wiggle room once everything has been planted in the one container. I’ve seen Harriet’s plantings, both at Whichford and online, and have no doubt that this is a system I need to master in order to take my container displays to the next level. As elsewhere in the garden, there are few things more impressive than seeing an effortless scheme seemlessly transitioning from one season of interest to the next, a continual dance as one performer retreats into the wings, and another steps forward to command stage. This is succession planting in pots. Time to play with the big kids.

The first things to consider when planting any container for the cooler months is drainage. In winter it’s all too easy for the soil to become waterlogged, and no plant likes to sit with its feet in water1. To that end, make sure that whatever container you’ll be planting into has adequate drainage holes, and be sure to use a free draining compost, incorporating horticultural sand or  grit – I’d be happy to use a ratio of one measure of sand to four of compost in order to make conditions a little more sharp. Add no water retaining gel or crystals – great in summer, but deathly in winter – and avoid composts to which these ingredients have been added (it should be clearly evident on the outside of the bag, probably with some daft marketing slogan “Now with ADDED Wet-Water Waffle” kind of thing).

But now comes the crunch, and, as so often seems to be the case with these things, the key would seem to be a matter of perception. Instead of viewing the container and its contents in two dimensions (front to back and side to side), we need to be mindful of four. The third dimension allows us to correctly position within the pot the bulbs which will be so important for creating interest and change in the spring – larger bulbs, like tulips, at a greater depth than smaller bulbs, such as crocuses, for example. With the introduction of a fourth dimension, time, we have to consider the display over a matter of weeks and months, as the initial winter planting gives way to the delicate freshness of early spring, and in turn the vibrancy of mid- to late-spring.

It makes for a much more crowded pot than I’m used to, but the lecture notes were full of advice as to the relative planting densities and depths for different bulbs and, as ever, Harriet’s been on hand in the online classroom to answer individual queries in person, and to discuss the other material covered this week, including colour schemes and arranging containers.

This week’s assignment asked us to create a planting plan for a pot 60cm wide by 30cm deep, providing winter interest while using bulbs to extend the season into spring. I’ve opted for a silvery grey colour scheme over winter, with white flowers, introducing pinks and blues as the weeks pass into spring.

Planting plan of the top layer of evergreen perennials and shrubs

The top layer features evergreen perennials and shrubs that will persist from winter through spring. Planted fairly densely, as there won’t be an awful lot of growth over the period for which this container will be on display.

A rather ropey detail shot of Calocephalus brownii 'Silver Bush'
1. A single Calocephalus brownii 'Silver Bush' as a centrepiece, trimmed to around 25cm in height and width, for its silver, coral-like foliag. Technically it’s a tender, semi-evergreen shrub, but here in the South East I’ve had no problems bringing this through winter in the relative shelter of a container display near the house. That said, we’ve not had a particularly cold winter for a few years now. A hardier alternative would be its distant relative, Santolina chamaecyparissus, but that does tend to get a bit brown and manky towards the base in the colder months. The curry plant, Helichrysum italicum, is reliably and persistently silver throughout, but I’m not sure about the smell in winter (though I love it in the warmer months)!

Heuchera 'Peppermint' Little Cutie Series. Image © Heucheraholics
2. Four Heuchera 'Peppermint', a small introduction in the 'Little Cutie' series, 15cm in both width and height, with strong, mid-pink flowers in spring

Cyclamen hederifolium 'Album'
3. Eight autumn flowering Cyclamen hederifolium alba for their wonderful ivy-like variegated leaves and delicate white blooms

Senecio cineraria 'Silver Dust'
4. Eight large plugs of Senecio cineraria 'Silver Dust' for the soft, grey oak-like foliage

The bulb layers next, in order of descending depth.

Crocus 'Ladykiller'. Image © Crocus
Crocus 'Ladykiller' (white flowers with outer petals tinted purple in Feb/Mar) 8cm high, planted at a depth of 5cm.

Muscari armeniacum Image © Crocus
Muscari armeniacum (blue flowers in April/May) 15cm high, planted at a depth of 7cm.

Fritillaria mealagris var. unicolor subvar. alba. Image © Crocus
Fritillaria meleagris var. unicolor subvar. alba (white flowers in Apr/May) 30cm high, planted at a depth of 10cm.

Tulipa 'Flaming Springgreen'. Image © Crocus
Tulipa 'Flaming Spring Green' (white flowers in May) 45cm high, planted at a depth of 18cm.

Tulipa 'Foxtrot'
Tulipa 'Foxtrot' (pink flowers in April/May) 30cm high, planted at a depth of 15cm.

Narcissus 'Fruit Cup'. Image © Crocus
Narcissus 'Fruit Cup' (white flowers in April) 35cm high, planted at a depth of 20cm.

With thanks to Crocus and Heucheraholics for the use of images.

1Except maybe the swamp cypress Taxodium distichum, and even they like to leave at least their knees out of the water. You’d need a very big pot for one of those, though.

Do have a look at the My Garden School website, which is still running its  Back to School campaign for 15% off all £145.00 4 week online courses in October. (Course start dates: Wednesday 7 October 2015). Click here and remember to use the code MGSBTS at the checkout for the discount.