More Annuals That Are Really Perennials: Lobelia, Nasturtium, Nicotiana, Petunia…

February 17th, 2017 | Plant Talk with Graham Rice | 0 Comments

Nicotiana langsdoffiiHere’s a second selection of plants grown as annuals that are really perennials, including two of the most popular in both forms: geraniums (pelargonium) and petunias.

Raising lobelia from seed can be a tricky business, the seeds are tiny and often damp off. But lobelia is a perennial and the best of all trailing lobelias for hanging baskets are propagated from cuttings. The problem is, cuttings-raised lobelias are not cheap and are rarely available. My solution: grow ‘Wonderfall’ seed-raised lobelia, but buy plugs.

After the very first summer when I grew Nicotiana langsdorffii (above) with its dainty dangling green bells, I cut the plants down in the autumn and left the roots in place – as I thought, to rot. The following spring I was surprised to find that the overwintered roots produced shoots and flowered again. They behaved just like hardy perennials and only require a warm site and fertile but well-drained soil.

Pelargonium (Geranium)
Until the 1960s, zonal pelargoniums (geraniums) were always raised from cuttings – partly because they took so long to flower when raised from seed. But new plant breeding techniques allowed plants to develop that grew much more quickly from seed. Now we have Divas, Maverick and the best seed-raised traditional red geranium ‘Moulin Rouge’.

But development of cuttings-raised geraniums has progressed too and plants in the semi-double Designer Series are exceptionally prolific, more rain resistant and flower for longer. ‘Designer Scarlet’ (below) has been used in the beds outside Buckingham Palace.

Since the 1800s, petunias have been raised both from seed and from cuttings but were originally often grown in pots in conservatories to protect their fragile flowers from rain. As with geraniums, more sophisticated plant breeding techniques led to more resilient petunias – seniors will remember ‘Resisto Rose’ (says he showing his age), as the first big step forward in weather tolerance.

Modern cuttings-raised petunias were developed from seed raised types and since then, in the development of both groups, one group has been used to improve the other. Doubles from cuttings, such as the Tumbelina Series, are especially good compared with seed-raised ‘Duo’ and ‘Pirouette’.

Tropaeolum (Nasturtium)
It’s easy to root cuttings of nasturtiums, just put them in a jar on the windowsill and they’ll root, and there are some superb fully double flowered types available as cuttings raised plants. But Mr F doesn’t list them, partly because gardeners think nasturtiums are easy and should be cheap and propagating them from cuttings commercially, and ensuring that they’re disease free, results in plants that are just too expensive. However lovely they are, people don’t buy them.

Geranium Designer Scarlet

Nicotiana langsdorffii close-up ©Magnus Manske licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Thank you.!

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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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