Archive for the ‘Plant Talk with Graham Rice’ Category

Cosmos time – yes, really!

June 14th, 2019 | Plant Talk with Graham Rice | 0 Comments

Cosmos 'Xanthos' and 'Sea Shells'

Well, it’s been raining hasn’t it… The problem is that everything is now growing like mad and spilling out into the spaces I’d set aside to sow cosmos.

Yes, I know. Cosmos are half hardy annuals and they’re often sown under cover in April. But both shorter varieties like ‘Xanthos’ (above left) and taller ones such as ‘Sea Shells’ (above right) do really well sown outside in June, sown outside where they’re going to flower.

The seeds are long and slender and easy to handle, the soil is moist, so all you need to do is draw a drill (a shallow furrow) in the soil with the point of a stick – or even your finger. About half an inch deep is fine and then you can place the seeds an inch apart and then just knock the soil in from the edges to cover the seeds and pat it all down with your hand.

Put a label in at the end of the row and another label or a piece of stick in at the other end, to mark the row and ensure that you don’t sow something else in the same space! The seeds will soon be up, they’ll grow strongly and you can thin them out, in stages, till they’re 15-20cm apart.

The problem is all those floppy plants that the rain has beaten down – in spite of the fact that you supported them (or perhaps because you didn’t!).

Well, they can be rescued, propped up, and space for those cosmos revealed. If you’re fortunate enough to have some flat sprays of hazel twigs, these are ideal for gently raising shoots back into position. But the simple device of two short bamboo canes with a length of string run between can also lift leaning stems back close to vertical. And snipping off any wayward shoots won’t do the plants any harm.

So, wait for a break in the rain, heave those floppy plants out of the way and get some cosmos seed in.

Growing happy hollyhocks

June 7th, 2019 | Plant Talk with Graham Rice | 0 Comments

Hollyhock (Alcea) 'Chaters Doubles'

So. Hollyhocks. Mine are just about to start opening and now’s the time to sow seed. Sounds odd, doesn’t it, to be sowing seed of biennials at a time of year when plants in the garden have not even started to ripen their seed.

In fact you can sow this month or next and this will give you large, well developed plants to overwinter and which are best placed to survive the almost inevitable attack from hollyhock rust.

For rust will surely strike, covering the shrivelling foliage with rusty coloured blisters. It struck mine so a couple of weeks ago I stripped off all the diseased leaves. If I hadn’t thoughtlessly pulled most of them up when they were tiny, the self sown larkspurs would have hidden the bare stems.

Hollyhocks come in three main types: tall biennials with single flowers (‘Giant Single Mixed’) and tall biennials with double flowers (‘Chaters Double Mixed’) – these are the ones to sow now – and short annuals with double flowers (‘Majorette’) to sow in spring.

Sow the seed thinly this month, in a short row outside, in the veg garden perhaps or in a bright space at the back of the border. Thin the plants to about 20cm apart then in September move them carefully to their final positions.

They can also be sown in pots and then the seedlings moved into individual pots but the plants will become quite large and may well need 12cm pots, or larger, to accommodate the vigorous roots.

If rust shows its ugly self then there are sprays approved for dealing with the problem. The RHS recommends Provanto Fungus Fighter Concentrate, Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect, Scotts Fungus Clear Ultra and Scotts Fungus Clear Ultra Gun. You can find out more about hollyhock rust, and an organic approach, on the RHS website.

But don’t let rust put you off – and be sure to allow your larkspur to self sow in the right spot.

Starting with stocks

May 31st, 2019 | Plant Talk with Graham Rice | 0 Comments

Double flowered stock (Matthiola)

Stocks seem to have become unfashionable. It’s all a bit mad, really, because stocks provide some of the most beautiful, most fragrant and longest lasting of cut flowers. But the best of them are tall, they need support and it can be fiddly to work out which of the seedlings produce the beautiful double flowers and which don’t. So they’re hard to find in catalogues.

The ones that you can get hold of with no trouble at all are the shorter ones such as ‘Brompton’ stocks, which are genuine biennials, and even shorter ones (‘Hot Cakes’ and ‘Ten Week’) which are usually grown as half hardy annuals.

Sow the taller, 45cm,‘Brompton’ stocks now or over the next month. There’s enough seed in the packet (150 seeds) that you can sow them in a row outside, thin them to 10-15cm, then either transplant alternate plants and leave the rest in place or move them all and plant them 20cm apart. If your soil is heavy then raise them in pots and plant them out in the spring.

Raise ‘Cinderella’ in the same way or, along with the short ‘Hot Cakes’ and ‘Ten Week’, wait till the spring and treat them as short-term half hardy annuals.

Either way, choose a sunny site for all of them with fertile but well-drained soil. ‘Brompton’ will need support as the flower stems extend in spring, a slim green cane to each one is usually enough. They’re best cut and brought inside where you can enjoy their colour and their wonderful fragrance.

More space, more shopping at this year’s Chelsea

May 24th, 2019 | Plant Talk with Graham Rice | 0 Comments

Okra and Orlaya

Down at the Chelsea Flower Show this week, seed has been flying off the Mr Fothergill’s stand. I spoke to Mr F’s David Turner, who’s been talking to show goers and answering their questions.

“We’ve sold more seed this year than in the last two years,” David told me, “and we’ve had some storming afternoons. And usually at Chelsea sales of flower seeds outstrips the veg but veg has been on top this year and we’ve had a surprising number of enquiries for okra.” Okra features on the Giving Girls in Africa a Space to Grow garden for CAMFED (the Campaign For Female Education), an African charity backed by Meghan Markle and Prince Harry.

“The RHS range of Award of Garden Merit seeds has done especially well this year with people asking for Ammi and rose campion in particular. And Orlaya, another informal white flowered annual, has also been popular.

“We also had a visit from Pudsey supporting our two children’s varieties, Sunflower ‘Pudsey’ and Pumpkin ‘Pudsey’, that raise funds for BBC Children in Need and his visit featured in the TV coverage.”

The other product that has gone well is Seasol, the organic seaweed concentrate plant tonic that promotes healthy growth of plants, flowers, vegetables and even lawns. I use it on my outdoor tomatoes and I’m sure that’s one of the reasons they develop such huge root systems.

Personally, I think one of the reasons sales have gone well is that the show is less crowded, more spacious this year and so visitors feel more relaxed and happier about carrying their purchases around. So they’ve bought more.

You can catch up on the last of the TV coverage of the Show today from 7:30pm-8pm on BBC One then from 8:30pm-9:30pm on BBC Two and finally tomorrow night from 8pm-9pm on BBC Two. Enjoy the show – in person or on TV.

Our future invaders

May 17th, 2019 | Plant Talk with Graham Rice | 0 Comments

Gunnera tinctoria

Amongst the dazzling colours of the Great Pavilion at next week’s Chelsea Flower Show, there’s a quieter and more reflective area that can be missed by visitors and TV cameras alike.

The Discovery Zone is the area for new ideas and new research and new science, the fresh thinking that will soon be reflected in the rest of the Great Pavilion and in gardening more generally.

Invasive species pose a threat to our native plants in their wild habitats, and at the University of Reading Tomos Jones has been looking at garden plants that might escape from our gardens and become invasive in the future. One surprising example is the giant rhubarb, Gunnera tinctoria. His Chelsea exhibit Ornamental plants: our future invaders explains.

“Invasive ornamental plants are often beautiful but they can have a range of detrimental ecological impacts,” said Tomos. “For example, giant rhubarb can grow over 2m tall and has huge leaves. It can out-compete other plants for resources, with very few others surviving in its shadow.”

Introduced to gardens from South America in the nineteenth century, it was first found in the wild in 1908 but is now increasingly seen in wet places, especially in the south. One flower head can produce 250,000 seeds so the potential for spread is clear.

“Gardeners have an important role in preventing and managing invasive plants,” continued Tomos. “They can be the first to observe plants showing signs of invasive characteristics. The information we collect from gardeners will help us identify and control species before they become a problem.”

The plant I’ve noticed that seems to be moving out of gardens is the Mediterranean Euphorbia characias. It’s starting to colonise village roadsides in my area of Northamptonshire and is also established on a roundabout on the M25 near Heathrow airport (below)!

You can contribute to this research by reporting your own experience of potentially problematic ornamental plants.

Tomos Jones said: “Many ornamental plants favoured by gardeners for their beauty have the ability to escape beyond the garden fence and have a damaging effect on the environment.

“Invasive plants that are not managed or disposed of responsibly can spread quickly and dominate landscapes, to the detriment of native species. We are asking the public to help identify plants showing invasive characteristics.” So have a chat with Tomos at the Show, or complete this online survey.

And don’t forget to take a look at the Mr F Chelsea stand. Why not stop by and say hello on stand EA475 on Eastern Avenue.

Euphorbia characias near Heathrow airport


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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