Tender Foliage Plants for Inside and Out

Dan Cooper, of Dan Cooper Garden, with his curated selection of stunning foliage plants for both indoors and outside. - 03 May 2024

May is when gardeners consider putting tender plants outside for the summer. My garden room and windowsills have been crowded with mature plants and cuttings for months, waiting for temperatures to lift high enough to survive on the other side of the glass. Many are plants principally admired for their foliage, including Solenostemon (formerly Coleus), Plectranthus, Pilea, Strobilanthes, Tradescantia and Begonia. I treasure these gems because they never miss a beat and look good year-round. All produce flowers, but their leaves are the main event, persisting for 12 months if they are happy.

Many foliage plants prefer benign, middling conditions - light but not too bright; shelter to stop their leaves from scorching; and warmth, but not cold or extreme heat. They enjoy humidity, especially once night-time temperatures reach 10ºC or above. However, they can be prone to attack from slugs and snails, which quickly diminishes their appeal. One should always be vigilant, particularly when the plants come back indoors in autumn - there’s often a stowaway or two in the drainage hole at the base of the pot!

Pilea 'Taiwan Silver'

Another great feature of this group of foliage plants is that they’re easily propagated. Most Coleus, Pilea, Plectranthus and Tradescantia root quickly if cuttings are placed in a glass of water. Begonias can be multiplied by leaf cuttings. The advantage is that you can soon build up stock if you fancy bedding a few plants out in summer or using them in pots and containers. They are all great fillers between ferns or ground cover under trees. And, if you don’t have space to bring them inside in autumn, you can sacrifice any surplus or take cuttings so they need less room over winter.

Here are my top 5 foliage plants for summering outside and overwintering indoors:

Tradescantia

These colourful, sprawling plants fell out of fashion for a while, but with the resurgence of interest in house plants, their ease of cultivation is appreciated again. I would not be without Tradescantia 'Purple Sabre' (a selection of Tradescantia pallida 'Purpurea' AGM), which produces long, trailing stems of damson-coloured foliage, occasionally tipped with a simple mauve-pink flower. When it gets out of bounds, the stems can be snapped off at a leaf junction and rooted in damp compost or water. It’s fabulous combined with Plectranthus argentatus 'Silver Shield' AGM and Begonia 'Benitochiba' AGM.

Tradescantia 'Purple Sabre', Plectranthus 'Silver Shield' and Begonia 'Benitochiba'

Tradescantia 'Maiden's Blush' is almost entirely hardy in my garden. I plant it under trees in dry shade. In spring, the new foliage is blotched with white and the growing tips develop a Bougainvillea-pink flush. Try growing it between ferns or in a pot with white Narcissi.

Begonia 

There is an increasing number of begonias marketed as hardy, but one that I’ve been growing for a long time is Begonia 'Benitochiba' AGM. It produces a low mound of palmate silver leaves with dark green accents around the veins and margins. Young foliage is flushed with a delicious purplish pink. I grow it in a pot and shelter it in a cold greenhouse over winter since it’s too good to lose!

Begonia 'Benitochiba'

I recently acquired Begonia palmata ‘Tye Dye’, which caught my eye with its large, velvety olive-green leaves, broken by a silver-green band—hence the name. Each leaf has a striking red reverse.

For something a little taller, seek out Begonia ‘Little Brother Montgomery’, which has leaves the shape of pop-art KERPOWs and a dark blotch at the centre. Or, if you like big leaves - and I do - track down Begonia koelzii, a splendid species from Manipur in India. Plants produce large, palmate, heavily dissected leaves on long stems, and if you’re lucky, substantial plantlets will form where the petiole meets the leaf. These can be removed and grown on. There are so many borderline-hardy begonias that you’ll be eager to experiment with more once you've started.

Begonia koelzii

Solenostemon (Coleus)

Given its cult following in the US and Scandinavia, I’m consistently amazed by our lack of interest in the genus Solenostemon. Fortunately, Dibley’s Nurseries has just extended its range, giving UK coleus enthusiasts access to many more cultivars - check out their stand at the Chelsea Flower Show. No other plant displays as much variation in leaf shape, colour, and texture, making it extremely hard to pick favourites, so I shall stick to readily available ones.

Anyone who has visited my garden or seen pictures of it will know Solenostemon ‘Henna’, a fine flame nettle with Chartreuse-green leaves and henna-red markings and reverses. It grows tall (up to 60cm) and bushy and will vary slightly in colour depending on how much light it gets.

Solenostemon ‘Henna’

S. ‘Campfire’ is even more striking, with sumptuous Corten steel-coloured foliage and a purple aura around its leaf edges. However, I find it extremely hard to place in my garden because it’s such a scene-stealer. Of smaller stature are S. ‘Burgundy Wedding Train’ and S. ‘Lord Falmouth’, older varieties that take some beating.

Solenostemon ‘Burgundy Wedding Train’

Solenostemon 'Lord Falmouth'

 

Grow them alone in a pot or urn and watch them form colourful mounds. If you’re looking for something a little different, the almost coral-like foliage of S. ‘Kiwi Fern’ or the kaleidoscopic shades of S. ‘Pink Chaos’ and S. ‘The Fume’ will make you drool.

Solenostemon 'The Fume'

Plectranthus

Plectranthus are closely related to Solenostemon and Coleus, keeping botanists amused but confusing the living daylights out of the average gardener. Plectranthus argentatus (now Coleus argentatus - you see what I mean?) is one of the best-known of the genus, quickly filling pots and borders with substantial mounds of silver-grey foliage and the odd spike of pinkish-white flowers at the end of the year. The cultivar ‘Silver Shield’ AGM is the classic, but if you can find the variegated ‘Hill House’, you’ll get the added attraction (or not) of creamy yellow edges. Propagation is effortless - you’ll often see root nodes appearing on the stems before you get around to taking a cutting.

Plectranthus argentatus 'Silver Shield'

Plectranthus zuluensis, with its cones of Wedgwood-blue flowers, has occasionally taken over my greenhouse border during the winter as it roots where it touches the earth. It’s not hardy, but it comes so easily from cuttings that you will always have a backup plant. It’s lovely late in the year when it blooms around the same time as nerines, providing a nice break from the antique shades of autumn.

Returning to foliage, P. ‘Velvet Elvis’ is a relatively new introduction with deep mallard-green foliage backed vibrant purple—that’s quite enough excitement for me, but as a bonus, lilac flowers appear as the nights get shorter. In common with all Plectranthus, ‘Velvet Elvis’ is resistant to most pests and diseases.

Plectranthus ciliatus 'Nico' and Plectranthus 'Velvet Elvis'

 Strobilanthes

The genus Strobilanthes tends to be known for its fancy-pants cheerleader, S. dyeriana, the Persian shield. It’s a stunning plant, producing long leaves with an almost reptilian texture, coloured in a dazzling combination of deep green, silver-grey and violet, but I have found it hard to keep going. The new kid on the block is S. sp. ‘Orizaba’ from Mexico, which has large, greenish-bronze leaves and a vigorous habit - it’s fabulous for an exotic border and can be cut back hard for overwintering. It has yet to flower in my garden but grew to 5ft in a pot.

Strobilanthes sp. 'Orizaba'

I discovered Strobilanthes wallichii, formerly known as Strobilanthes atropurpurea, at Trebah in Cornwall and have grown it in my garden ever since. Foliage-wise, it’s not going to stop the traffic, but provided it’s mild enough, it will flower almost 365 days of the year, producing hooded, violet-blue flowers reminiscent of a salvia. Last but not least, I have finally succumbed to the charms of Strobilanthes anisophyllus ‘Brunetthy’. It looks a little like Sarcococca hookeriana (winter box), but the leaves are almost black, and the flowers are pale pink but unscented - I guess one can’t have it all! I have it planted in a pot with lime-green foliage, which looks terrific. It has become more commonplace, so watch for it the next time you plant shop.

Dan Cooper is a plantsman, presenter and publisher of the acclaimed blog, The Frustrated Gardener. After a decade of sharing his love of gardening, he took the natural next step and launched Dan Cooper Garden – the first retailer of its kind. He now uses his personal experience to select the finest garden products and pair them with expert advice, all in one place.

Website: www.dancoopergarden.com