Archive for the ‘Plant Talk with Graham Rice’ Category

King of the foxgloves

March 16th, 2018 | Plant Talk with Graham Rice | 0 Comments

Digitalis 'Summer King'
Back in 1924, D. H. Buxton of the John Innes Horticultural Institution, then in Merton in south west London, created a hybrid between our native foxglove and Digitalis grandiflora, a yellow flowered species from Eastern Europe. This was news because the two species had always been thought to be incompatible.

In fact he raised fifty seedlings, all from seed set on our native plant with pollen from the yellow-flowered one. He then pollinated one of the seedlings with its own pollen and raised ninety six plants which were identical to the parent and which themselves produced lots of seed.

So out of two plants thought never to produce seed when crossed together he’d produced a new fertile form that could easily be raised from seed. This plant was called Digitalis x mertonensis.

A number of varieties have been developed over the years and ‘Summer King’ is one of the best. In a trial run by the RHS at its garden at Wisley a few years ago ‘Summer King’ was described as “Multi-stemmed and very good flowering. Flowers held well on spike. Self-cleans beautifully.”

It’s a little like a more compact, more showy form of our native foxglove with spikes crowded with flowers the colour of strawberry ice cream on the outside and raspberries on the inside.

If you like foxgloves, give ‘Summer King’ a try. If you don’t, this one will probably convert you.

New for shady baskets

March 9th, 2018 | Plant Talk with Graham Rice | 0 Comments

Streptocarpus 'Santiago'

You want me to do what? Put a streptocarpus in my hanging basket? Yes, but not your regular streptocarpus. This one is different.

Streptocarpus saxorum is a species from East Africa which is occasionally seen in botanic gardens and specialist collections. In the wild it makes rather a straggly plant, sprawling over the forest floor or on damp banks and producing occasional pale lilac flowers with white throats. ‘Santiago’ is a much improved version.

Firstly, it branches repeatedly and more branches mean more flowers. Secondly, the flowers are a lovely light blue in colour with a white eye and a few blue whiskers. Very pretty. Thirdly, ‘Santiago’ has a longer flowering season, May to October. And, finally, the foliage is a little neater so that the flowers are shown off more effectively.

The origins of ‘Santiago’’ seem unclear, although I found a Latvian website featuring the plant where – translated by Google – I’m assured that: “Suspended potatoes also grow stony sturgeon”!!

This is a lovely hanging basket plant for a shady place, it dislikes full sun, and it’s even more important than for other basket plants that it stays moist. I’d also suggest either growing it as a specimen, without companions, or perhaps with only white trailing lobelia for company

Either way, ‘Santiago’ is a valuable addition to the rather small selection of blue-flowered basket plants. Why not give it a try?

Kudos for ‘Kudos’ agastache

March 2nd, 2018 | Plant Talk with Graham Rice | 0 Comments

Agastache 'Kudos Coral', 'Kudos Mandarin' and 'Kudos Yellow'

One of the great things about getting to try new varieties before they appear in the catalogue is that I can grow them and report on them for you at ordering time. Step foreword the ‘Kudos’ agastache. These are superb.

The neat foliage is fragrant, the flowers start to open early (some had already developed their first buds when the young plants arrived), they were in full flower when still quite small and they bloomed more and more as the plants became established. Right through to the frosts.

One of the reasons that they looked so impressive for so long was this: the flowers are small and are produced in clusters at the leaf joints. But the flowers in each cluster open in a long succession so there are always open flowers all the way up the stem.

Also, the plants throw new stems from the base at the same time as the older stems are flowering so they become steadily more prolific. The bees love them, and they’re good for posies.

I’ve just been out to look closely at how well they’ve come through the winter – but of course they’re under the snow. But when I was tidying through last week I noticed that they’re all starting to develop new shoots at the base.

There are seven varieties in the Kudos Series, and Mr F have chosen the best three: ‘Kudos Coral’ has dark coral red plumes with a honey-mint fragrance to the foliage; ‘Kudos Mandarin’ is vivid mandarin orange with more citrus-flavoured foliage; ‘Kudos Yellow’ is a bright but soft yellow with, I thought, a touch of eucalyptus in the aroma. All thrived for me last year and I’m looking forward to some early flowers – once the snow passes and allows them to grow. Give them a try… Sun and reasonable drainage is all they need.

Mediterranean must-have

February 23rd, 2018 | Plant Talk with Graham Rice | 0 Comments

Cerinthe major 'Purpurescens'

Cerinthe is relatively new in our gardens. It’s not a flamboyant plant and until about thirty years ago it was very rarely seen. But one particular variety began to catch our attention, Mr F spotted the growing enthusiasm and so it’s listed here, both as seed and as plants.

Cerinthe major is the species with the largest flowers, and is found around the Mediterranean, on both the African and the European sides, often where the soil retains a little moisture. It makes an upright, rather succulent plant whose seed often germinates in the autumn and flowers in spring.

The tubular flowers hang down in clusters and are usually yellow and white but in ‘Purpurascens’, the variety to look for, they’re deep purple and surrounded by smoky purple-tinted bracts. The flowers are very popular with bees, which explains its common name: honeywort..

Seed can be sown in autumn or spring – as usual with Mediterranean plants autumn sowing produces better plants, and they’re happy in any reasonably fertile soil in sun. They’ll flower for months, especially if deadheaded.

The stems also last well when cut, which is perhaps surprising when you see how succulent and juicy they are. Searing the ends in boiling water for twenty seconds will ensure that they last at least a week, and often ten days.

But don’t cut or deadhead all the stems, leave some to make seed and self sow and you’ll never be without this colourful and intriguing flower.

Get ahead with spring sowing

February 16th, 2018 | Plant Talk with Graham Rice | 0 Comments

Calendula 'Snow Princess'

Well, last week I was talking about seeds not to sow this month, so this time I’m reversing the idea – what can we sow now that we should have sown in the autumn?

I’m always bashing on about how autumn is a really good time to sow a number of popular annuals, especially those that grow naturally in the Mediterranean region where they germinate at the end of summer and in autumn as the rains begin. Sweet peas, nigellas, cornflowers, cerinthe, calendulas, and annual chrysanthemums all produce superb plants from an autumn sowing. But we don’t always get round to it. So can we sow them now and still get ahead of the usual March or April sowing? Yes, we can.

The problem is that in February the soil is so cold that germination is very slow and slugs and rots of all kinds can kill seedlings before they get anywhere. But if we can get them to start to grow in February they’ll make better plants than if they’re sown a month later. Here’s what I suggest.

If you have a cold greenhouse, then you’re all set. Sow sweet peas in Rootrainers and the others in regular modules, sow them and grow them on in the cold greenhouse and plant out in April.

But, if you don’t have a greenhouse, here’s what to do. Sow the seeds in Rootrainers or other modules and keep them in the house, anywhere warm. The seeds need more warmth for speedy germination than they do for growing. Then, as soon as the seeds show signs of emerging, move them outside. Don’t wait until their leaves unfurl and the stems start to stretch. Where, exactly, you move them is important.

Choose somewhere warm and cosy, a position that benefits from as much low late winter sun as possible. Ensure that surplus moisture can drain away and, crucially, protect the emerging seedlings from slugs. I use organic SlugClear™ Ultra³  slug pellets which I find work very well.

I used this method with sweet peas and with calendulas last year, I’m expecting to prove the point with other annuals this this year. Why not give it a try?

Is one of our best known gardening writers. A graduate of the Royal Botanic Gardens, Kew, Graham was previously Gardening Correspondent of The Observer.
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