Hartley Magazine

All the latest news, hints, tips and advice from our experts

Summer Splendour for Full Sun

Plectranthus and Pelargonium ‘Attar of Roses’ in old wine crate

The weather can cut up rough at this time of the year, particularly when you live in Cold, Cold Aston as I do. I always say that the clue is in the name! It’s a chilly little spot, perched on a plateau on top of the North Cotswold in an area known as the Empty Quarter, because most sensible people chose the shelter of the valleys. The wind usually whistles in from the south-west and rain often follows, so my greenhouse is my inner sanctum. I can escape the spring squalls and the summer downpours and so can my plants!

My Hartley allows me to pot up my summer containers in April and this gives them plenty of time to fill the pots before my glorious creations go outside in the first week of June. They’re already looking summery. I can also raise my own plants from cuttings, overwinter plants and sow seeds. In short, my Hartley is my equivalent of this child’s playpen and I wouldn’t be without it!

It’s worth the effort, because well-placed beautifully grown containers can be use used to frame doorways, distract the eye from a part of the garden that’s basically messy, or fill a blank space. They need to be interesting from June until October and, in my garden, they need to be low maintenance so they can a miss a day’s watering without blinking an eye. Most of all, they need to be long-flowering plants and that normally means two things. They either get deadheaded, or they are non-seeding sterile hybrids produced by years of selection.

You need to pack in the plants, so if you can raise a few of your own, for little effort, all well and good because you’ll save some money.  Raising your own also means that you can pick stylish plants, rather than just grabbing something from the supermarket or garden centre shelf wants to sell you. Although I’m not completely averse to grabbing a few this and that’s.

You can also be creative with the actual containers in summer. I use old wine crates, galvanized containers with holes drilled into them, wire mesh baskets and wicker. I’ve seen people use old boots, children’s wellingtons and jute sacks. Before you get too carried away though, larger well-filled arrangements are easier to manage on the watering front. They also have far more eye appeal than lots of tiddlers. Less is more, as one of my more stylish close friends says.! And always use pot feet, because this aids drainage.

Sun Loving South Africans

South African plants are great survivors in sunny places and many of them are natives found on The Cape of South Africa. Going there was an eye opener for me, for I thought it would be a tropical paradise. However, The Cape is rugged in form with the sort of terrain that looks almost Scottish highland.  The soil is acidic and low in nutrients and the weather can be pretty frisky at times too.

The climate caries according to which side of The Cape you’re on. In simplistic terms the semi-arid Eastern Cape gets summer rainfall, peaking in August, and it also gets winter rainfall. The Western Cape has a Mediterranean style climate with warm to hot, dry, sunny summer weather and mild, rainy conditions in winter. Most evergreen agapanthus species come from the Western Cape, because they do their growing in damp, mild winters.  Deciduous forms are found in more arid areas and they tend to be hardier and the foliage is neater.

Agapanthus make wonderful container plants and I use them along the front of Spring Cottage. There is a myth that you have to starve them to get them to flower. It’s wrong in so many ways. They must be well-watered and well-fed and tomato food, applied every 10 to 14 days between May and August, is the way to go. They overwinter well in unheated greenhouses, as long as watering tails off by the end of September. They can also be overwintered outside too. Find the most sheltered spot you have and just lay the pots on the side so winter wet doesn’t do for them. Pots of lilies can also be overwintered like this.

When it comes to pots, rugged terracotta’s best and you need to avoid tapering pots, because top-heavy agapanthus will blow over in them. My favourites ones are the dark-blue and very floriferous ‘Alan Street’ (from Avon Bulbs), and the deciduous mid-blue ‘Northern Star’ and the tall and elegant grey-blue ‘Windsor Grey’. They work really well in pots, because you’re elevating the flowers. These are held on rubbery stems and they splay out well. They will need dividing every third or fourth year in spring and this can be a strenuous job. Commercial growers sometimes use chain saws! The technique is cut large chunks and place them back into potfuls of new compost. The chunks need to fill about two thirds of your pot, or slightly more. If the chunk’s too small for your pot, your agapanthus will spend a year producing new leaves at the expense of flowers.

The pelargonium also inhabits The Cape and you find large woody bushes on the nature reserves. They experience airy conditions and rainfall and, when you’re overwintering pelargoniums, they need to frost-free conditions that aren’t too warm in winter. They also need to be kept slightly damp. If they get too dry, they go backwards and may even die. Fuchsias and heliotrope need the same treatment in winter: they mustn’t get too dry but they also need more heat than pelargoniums.

I love the scented-leaved pelargoniums and the pleasant ones can smell of mint, apple, lemon, chocolate and rose. The less-pleasant ones are straight from the hardware store, turpentine, paraffin and paint. Don’t do too much sniffing though. I once got a serious headache because I had to describe thirty of them for an article! It lasted for three days, although I am a compulsive stroker of foliage.

Agapanthus ‘Northern Star’

Their pink and white flowers tend to be small and insignificant, but extremely bee-friendly. Their diverse foliage is interesting and I am particularly fond of the roughly textured maple-leaved, lemon-scented ‘Mabel Grey’ and the highly divided rose-lemon ‘Radula’. Both are quite large and upright when fully grown so they make good focal points.

My two easiest pelargonium fillers, because they propagate so easily, are ‘Attar of Roses’ and ‘Grey Lady Plymouth’. The white-edged grey-green leaves of Grey Lady Plymouth are fragile wisps of cloud, but ‘Attar of Roses’ has hirsute matt-green foliage.

Take cuttings between July and August and remove any buds. The stems should be firm, not woody, and they need to be about 2 – 3 inches long. I plunge these into small seed trays full of damp, coarse horticultural sand and they root easily in a shady corner of the greenhouse. They are potted up in September, or in February in a greenhouse with a frost-breaking heater.

My favourite pelargonium for single pots is Copthorne. Because it makes strong plants. The large mauve-pink flowers are streaked in purple-red and they’re held above good green foliage. This pelargonium really fills a pot to perfection. Fibrex have the best stocks at affordable prices.

Most gardeners know and use pelargoniums, but fewer of them know about Plectranthrus. These are tender plants related to coleus, although these are now known as Solenostemon. Most gardeners remember their colourful foliage sitting on windowsills.  Plectranthus are very closely related and the most useful is the silver-leaved P. argentatus.  This has large velvet-textured serrated silver foliage held on square stems and spires of insect-friendly purplish-white tiny flowers follow. There are others and one, ‘Hill House’, has variegated foliage cream and silver foliage. This came from the late Raymond Hubbard’s wonderful Hill House Nursery in Devon, which is now run by his son.

All that silver and pale-green deserves a splash of colour and heliotrope (Heliotropium arborescens ) is my preferred option, because it flat heads of tiny purple flowers and a vanilla scent. It is more difficult to overwinter, because it needs more warmth because it’s native to Bolivia, Peru and Columbia. ‘Marine’ and ‘Chatsworth’ are both heavily scented and it has the name cherry pie. The slugs also like to nibble it! It’s a plant for hedonists and very hedonist deserves a Hartley!