Growing exotic plants from seed on the cheap

Blog: Mac’s Mix XV from Chiltern Seeds – a game changer for me!

If growing exotic plants from seed on a budget is your aim and you like a challenge, you can’t beat Mac’s Mix seeds from Chiltern Seeds. In case you’re wondering, Mac was the office cat! There’s a new collection of tender and tropical seeds every year from around the world. There’s a vast selection, and when I got the full list, I was gobsmacked. So many plants I have never heard of, and all for £3.75.

The seeds themselves are a huge variety, from a couple of huge sea beans, canna offshoots and every shape and colour you can think of. You can sow them at any time, and a propagator is ideal, as they need a consistent 25°C, although a warm windowsill is possible.

Soak seeds overnight

The bigger, hard-coated seeds needed to be soaked overnight. I sowed mine according to size for ease. The sea beans and cannas in their own pots, another group of black seeds (which turned out to be senna), then in modules, if I could pick them up. Lastly, the finest seeds were sown in a couple of seed trays.

As warned on the packet, germination for growing exotic plants from seed is erratic, starting within a week, but some can take up to a year. When a module seedling poked through, I cut it away from the rest to grow on in cooler conditions. By early June, everything that has germinated has been potted on, and one unidentified plant has flowered, with large white trumpets. White morning glories and cardinal climbers have also bloomed and are now outside. Anything that has germinated and is identified is in red.

Growing exotic plants from seed

This is the problem – growing exotic plants from seed mix contains a huge variety of species that will need different care. The thing is, the plants are very hard to identify until they have adult leaves or flowers. I’ve found that keeping them in the conservatory in dappled sunlight has worked, on a heat mat set at 15°C.

Most can probably go outside for a spell in summer, but I won’t risk it until they are properly identified. On that note, here’s the full list of exotic plants. It has taken some research; there are some very rare plants in there. Don’t expect all of them, though! Please note that these collections of exotic plants from seed change every year according to availability. This is the XV collection.

A is for Acacia

• Acacia koa: Hawaiian tree up to 25m. Bipinnate compound leaves with 12–24 pairs of leaflets. At 6–9 months old, thick, sickle-shaped ‘leaves’ called phyllodes grow. True leaves are replaced by these phyllodes. Flowers are pale-yellow racemes 8-10mm wide.
• Aiphanes horrida (Coyure palm, ruffle palm, spine palm): South American, spiny palm to 10m with curly leaves and wedge-shaped leaflets. The edible seeds taste like coconut with a less chewy texture.
• Alcea nudiflora: NW China and Kazakhstan native, this rare hollyhock-like plant, to 80cm, has large white flowers with yellow-green centres.
• Annona mucosa (Rollinia deliciosa, biriba, wild sugar apples): Tender deciduous South American tree to 4m in gardens. Dark green, simple leaves up to 35cm long. Scented flowers are greenish-yellow, 4cm wide, in the leaf axils. The yellow, sweet fruit has soft spikes, weighing up to 1kg.
• Annona muricata (soursop): Caribbean and Central American evergreen tree to 9m. Dark glossy green leaves are oval, up to 16cm long and 7cm wide. Flower petals are thick and yellow, 3cm in diameter. Dark green fruits are prickly, up to 30cm long, with juicy, acidic, whitish flesh.
• Areca triandra (wild areca palm): SE Asian suckering evergreen palm to 7m. Each crown of leaves is up to 180cm long. Survives light frosts down to -2.5°C.
• Argemone mexicana (Mexican poppy, Mexican prickly poppy): Hardy, drought-tolerant 60cm annual. Bright yellow latex. Prickly, glaucous foliage, blotched white. Large lemon-yellow or orange, poppy-like flowers. Prickly seed pods. Poisonous

Growing exotic plants from seed – Dutchman’s pipes

• Aristolochia elegans (calico flower, Dutchman’s pipe): Climber to 6m with pale green, heart-shaped leaves, and fragrant flowers in August. Each flower is up to 10cm wide, looking like an ear trumpet, in purplish-brown netted with white. Minimum temperature of 10°C. Poisonous
• Aristolochia fimbriata (white-veined Dutchman’s pipe): Brazilian climber to just 90cm with smooth, kidney-shaped leaves and small, purplish-brownish-yellow flowers, decorated with a conspicuous fringe. Poisonous
• Aristochia grandiflora (pelican flower, calico flower, elegant Dutchman’s pipe): Tender woody twining plant to 8m with oval leaves. Swollen, tubular flowers, brownish-purple with white veins and variegation. Full sun or half shade. Poisonous
• Aristolochia littoralis (calico flower, elegant Dutchman’s pipe): Tender, evergreen climber to 8m with heart-shaped, greyish leaves and 10cm brownish-purple flowers, veined with creamy-white. Very long-lived. Poisonous
• Aristolochia ringens (gaping Dutchman’s pipe): Brazilian evergreen climber to 7m. Roundish kidney-shaped leaves, with 20cm flowers. Each greenish-purple bloom has a swollen sac, from which a cylindrical tube divides into two long lips. Poisonous
• Averrhoa bilimbi (cucumber tree): SE Asian shrub to 3m with pinnate foliage from spring to autumn. Held directly from the trunk or branches are short panicles of dark reddish-purple flowers followed by small, cucumber-like fruits.
• Averrhoa carambola (star fruit): SE Asian tree to 14m. Leaves are spirally arranged. Pinkish-purple flowers grow from where the leaf joins the stem or directly from the stem. Edible fruits, star-shaped in cross-section, are dark yellow when ripe.

B is for Bixa

• Bixa orellana (annatto, lipstick tree, achiote): Evergreen tropical South American tree to 4m. Broad, heart-shaped leaves and panicles of large, peach flowers. Annatto dye is prepared from the seeds.
• Broussonetia papyrifera (paper mulberry, tapa cloth tree): East Asian shrub/tree to 15m with very woolly, variously lobed leaves. Fibre from its bark is used for making paper and cloth.

C is for Calliandra

• Calliandra calothyrsus (red Calliandra): Multi-stemmed shrub to 6m, evergreen in humid climates. Attractive red ‘powder puff’ flowers.
• Cananga odorata (ylang-ylang): Fast-growing, very fragrant tree to 12m with frilly yellow flowers. Can grow 5m a year, slower and smaller in a container.
• Canna, Mixed Dominican Republic Series (Indian shot): Chiltern Seeds’ own mix from a supplier in the Dominican Republic (also includes seeds from Haiti and Belize). Plants up to 2.7m.
• Canna tuerckheimii (Indian shot): Central American native and largest canna at 4m. Very large leaves and reddish-pink flowers. Not cold hardy – store indoors over winter.
• Carica papaya (common pawpaw): Edible South American tree to 6m. Single, upright stem topped with a palm-like spread of large, deeply divided leaves. Cream, scented flowers develop directly from the trunk, followed by large yellow or orange fruits.

Growing exotic plants from seed – senna!

• Cassia alata (Senna, Emperor’s candlesticks, ringworm bush): Shrub to 3m with pinnate foliage that closes at night. Upright spikes of yellow and orange flowers. Fungicidal and laxative properties.
• Cassia fistula (golden shower tree): SE Asian tree to 15m bears fragrant, long racemes of yellow blooms. Thailand’s national flower. It never has leaves and flowers at the same time.
• Chrysophyllum cainito (star apple): West Indian evergreen tree to 20m. Simple leaves with golden undersides, tiny, fragrant purplish-white flowers. Purple 10cm round fruit.  
• Clianthus puniceus var. maximus (Glory pea, kaka beak): New Zealand native to 3m, large red flowers hang in clusters of 15-20 blooms. Bright green seed pods turn brown and split open when dry.
• Clitoria fairchildiana (butterfly pea tree): Brazilian deciduous or evergreen tree to 15m with a spreading crown of simple leaves and racemes of purple flowers.

Growing exotic plants from seed – butterfly peas

• Clitoria ternatea (butterfly pea): SE Asian evergreen climber to 2.4m with blue, exquisitely marked flowers.
• Clitoria ternatea, white-tinted blue (butterfly pea): Similar to the above but with very pale blue flowers.
• Clusia rosea (the autograph tree): West Indies/tropical Americas evergreen tree to 10m. Good houseplant with handsome, leathery leaves. 
• Coix lacryma-jobi (Job’s tears): A 90cm ornamental grass with reed-like leaves and large, pearly-white edible seeds drooping like tears from the stems.
• Coix lacryma-jobi Ma-Yuen (Job’s tears, Chinese pearl barley): Cultivated variety of the above, harvested as a cereal crop, with a soft shell, and used medicinally in Asia.
• Cordia sebestena (Geiger tree): Central American evergreen or deciduous tree to 10m. Large orange-red flowers, edible fruit.
• Cornus kousa (Chinese dogwood): Shrub to 8m with large, creamy-white, petal-like bracts. Flowers for weeks, hardy throughout the British Isles.
• Crescentia cujete (calabash tree): Evergreen tropical American tree to 10m. Dark glossy green leaves, yellowish flowers and fruit known as calabash, used as cooking pots or percussion instruments.
• Crinum mauritianum (swamp lily, Mauritius lily): Mid-sized semi-aquatic lily to 70cm. Can be grown in soil. Umbels of white flowers and partially succulent, upward curving leaves.
• Cubanola domingensis (Dominican campanita): Evergreen shrub to 2m from the Dominican Republic. Glossy, leathery foliage and fragrant, creamy-white trumpet flowers.

D is for Datura

• Datura stramonium (thorn apple, jimsonweed, devil’s snare, devil’s trumpet): Notorious hallucinogen, a stout and vigorous branching plant to 90cm with white, funnel-shaped flowers. Prickly, egg-shaped and very poisonous fruits. See my in-depth post!
• Diospyros dignya (black sapote, chocolate pudding tree): Central/South American evergreen tree to 25m. Black bark, glossy, dark green leaves. Its dark brown fruit is eaten raw when fully ripe and/or cooked.
• Gaussia maya (Maya palm): Central American palm to 6m with a ringed trunk, bulbous at the base when young, and a loose head of pinnate fronds.

G is for Gladiolus

• Gladiolus dalenii (dragon’s head lily): Deciduous evergreen perennial to 2m. Grey-green leaves in a loose fan with large, scarlet-orange hooded flowers with a yellow throat; bracts green to red-brown.
• Gossypium herbaceum (cotton plant, Levant cotton): Commercial cotton to 1.2m. Yellow and maroon flowers, followed by fruits that burst open to reveal white bolls.

H is for Hibiscus

• Hibiscus rockii (Hibiscus calyphyllus): Tropical African shrub to 1m bears lemon-yellow blooms with maroon throats.
• Hibiscus sabdariffa (roselle): Vigorous annual to 2.1m with large, dark green leaves on reddish stems, bearing red-centred, pale yellow flowers with shiny red, fleshy calyxes.
• And finally, Hibiscus storckii (Storck’s hibiscus): Rare plant from Fiji with shiny green foliage to 3m. Pink and cream flowers have a red centre.

Growing exotic plants from seed – I is for Ipomoea

• Ipomoea hederifolia ff. Lutea (yellow trumpet morning glory): Mexican annual climber to 3m. Dark green foliage and long-stalked clusters of small, yellow, funnel-shaped flowers.
• Ipomoea ochracea (fence morning glory): West Indian climber to 4m with soft yellow flowers. Perennial or annual.
• Ipomoea x multifida (cardinal climber): Tender annual vine to 4m, flaring trumpet-shaped blooms produced every morning in brilliant crimson that look like little morning glories.
• Ipomoea alba (white morning glory, moonflower): Tender climber to 3m for under glass or sheltered position outdoors. White flowers from June to September. (NOTE: I have these in my packet, although not on the original list.)

J is for Jatropha

• Jatropha podagrica (Guatemalan rhubarb): Succulent with large, three-lobed, smooth, waxy leaves, and a grey-skinned, much swollen, club-shaped stem to 60cm. Scarlet, long-lasting flowers. Minimum temperature of 10°C.
• Jatropha multifida (coral plant, coral bush, physic nut): Mexican/Caribbean semi-succulent, evergreen shrub to 7m. Large, rounded, divided palmate, dark green leaves. Flattened clusters of scarlet flowers.

K is for Kigelia

• Kigelia africana (sausage tree): African tree to 18m with large leaves and red velvety, bell-shaped flowers followed by 60cm sausage-like fruits.

Growing exotic plants from seed – L is for Latania

• Latania loddigesii (Blue Latan palm): Madagascan palm to 12m. Silver-blue fan-shaped leaves intensify with age, edged with red. Leaves and stalks are covered in dense, fine woolly fibre.
• Lessertia frutescens (Sutherlandia frutescens, cancer bush): South African shrub to 1m with red flowers followed by unusual balloon seed cases.
• Luffa cylindrica (loofah): Grows like a greenhouse cucumber, reaching 3m. Fruits are edible when young.
• Leea guineensis (West Indian holly): Tropical African evergreen shrub to 6m. Deeply veined, almost corrugated, shiny leaves, light green when young, turning dark green. Small flowers in dense sprays up to 20cm across, vermilion above and orange/yellow beneath.
• Livistona rotundifolia (footstool palm): SE Asian fan palm to 12m. Dense crown of fronds on thorny red stalks.
• Livistona chinensis: Half-hardy palm to 9m. Fan-like leaves require a minimum temperature of 2°C.

M is for Majidea

• Majidea zanguebarica (black pearl tree): Semi-deciduous tree to 10m. Clusters of red and green flowers followed by red seed pods with black, velvety seeds.
• Malpighia glabra (wild crapemyrtle, Barbados cherry): Central American shrub to 2.5m with a rounded canopy of delicate foliage. Small pink flowers and red, tart fruits are high in vitamin C.
• Manihot esculenta (cassava, manioc, tapioca, yuca): South American woody shrub. Leaves are simple and deeply lobed; flowers are inconspicuous. The raw tuberous roots are toxic unless properly prepared and cooked. Poisonous
• Merremia dissecta (Alamo vine, cut-leaf morning glory, mile-a-minute, wood rose): Central American climber to 3m with attractively divided leaves and white, morning glory flowers with a pink throat.
• Merremia tridentata: Tropical Africa, Asia and Australia. Prostrate, twining plant to 4m with morning glory-like flowers in pale yellow with maroon centres.

Growing exotic plants from seed – Four O’Clock flower

• Mirabilis jalapa, rose pink form (Four O’Clock flower): Bushy perennial to 90cm, grown as a half-hardy annual. Covered with fragrant, trumpet-shaped flowers that appear from 4pm. Different coloured flowers appear on the same plant.
• Molopospermum peloponnesiacum: Mountainous central/southern Europe. Aromatic plant to 1.8m with shiny, fern-like foliage and yellowish-white flowers in spring.
• Momordica charantia (bitter melon): Tropical climber to 2.4m with five-lobed, vine-like leaves and vanilla-scented yellow flowers. Bright orange, rugby-ball-shaped fruits six inches long that split open to display a scarlet lining.
• Morinda citrifolia (noni, cheese fruit, vomit fruit): SE Asian/Australasian tree to 9m with large, simple, dark green, shiny and deeply veined leaves. Fruits start green, then yellow, ripening to almost white with many seeds, oval in shape and reaching 18cm, with a pungent odour.
• Moringa oleifera (drumstick tree, horseradish tree): Indian tree to 5m. Much-divided, soft, clear green leaves with large, loose sprays of honey-scented, cream flowers. Use roots as a horseradish substitute. The mustard-flavoured leaves, twigs and flowers can be used in salads and curries.
• Mucuna sloani (hamburger bean, horse-eye, deer’s eye, sea bean): Perennial climber with tripartite leaves and rope-like hanging clusters of large, greenish-yellow, fragrant flowers followed by pods with large, very hard seeds.

N is for Nerium

• Nerium oleander, Mixed colours (oleander): Evergreen shrub to 2.5m with narrow lance-shaped grey-green leaves and clusters of salver-shaped, pink, white or red flowers 3-4cm across.

Growing exotic plants from seed – O is for Olearia

• Olearia pannosa cardiophylla (velvet daisy bush): Rare low spreading shrub to 1m from the Southern Flinders Ranges in Australia. Large white daisy flowers with heart-shaped leaves.
• Oroxylum indicum (tree of Damocles, midday marvel-midnight horror, Indian trumpet flower): Indian tree to 10m with very large, much-divided, glossy green leaves. The first name celebrates the lethal-looking 1.2m long seed pods. The second refers to the papery seeds, shed around noon and the purple, evil-smelling blooms appear at night.

P is for Parmentiera

• Parmentiera aculeata (cucumber tree): Central American tree to 6m bearing large green/purple flowers directly on the trunk, followed by bunches of 20cm-long fruits that resemble cucumbers.
• Phoenix roebelenii (pygmy/dwarf date palm): SE Asian palm to 2.5m with a slender trunk, pinnately divided leaves to 1m, small yellow flowers and edible black fruit.
• Phyllanthus juglandifolius (bigleaf leafflower): Caribbean/South American shrub to 3m with an unbranched trunk topped with a palm-like crown of leaves.
• Pseudocalymma alliaceum (garlic vine, wild garlic, amethyst vine): South American semi-woody vine to 2.5m with tri-colour lavender/white blooms. Leaves (not flowers) smell like crushed garlic.
• Psidium cattleianum (strawberry guava): Brazilian tree to 1.8m in a pot. Smooth, leathery leaves and deep claret coloured fruits with a flavour like strawberries.
• Pachypodium rosulatum (elephant’s foot plant): Succulent dwarf shrub to 35cm from Madagascar forms a short, inflated base with slender, twisting, nearly spineless branches. Sparse crown of simple leaves and yellow trumpet-shaped flowers.
• Passiflora foetida (stinking passionflower, wild maracuja, bush passion fruit, wild water lemon): Creeping vine with edible fruit – stinking refers to the crushed foliage. The flowers are cream, 6cm wide. The 3cm globular fruit is yellowish-orange to red when ripe.
• Pritchardia pacifica  (Fijian fan palm): Tongan palm to 15m with a smooth, greyish tan trunk and 1.2m wide and equally long fan-like leaves.
• Ptychosperma macarthurii: Australian palm to 5m with multiple slim grey trunks topped with broad feathery leaves.

S is for Schinus

• Schinus terebinthifolius (Brazilian peppertree): Sprawling shrub or tree to 10m. Alternate 10–22cm long, pinnately compound leaves with yellowish veins. Small white flowers in clusters. The fruit is 4–5mm in diameter.
• Simarouba berteroana: Neotropical tree with compound leaves made up of alternate pinnate leaflets. Small, 1cm flowers arranged in large panicles.
• Syagrus romanzoffiana, dumpy form (queen palm, cocos palm): South American palm to 15m, but a popular container tree. Pinnate leaves with around 300 leaflets, each 50cm long. Hardy to -5°C, edible fruits.

T is for Tabebuia

• Tabebuia caraiba (silver trumpet tree, tree of gold): South American tree to 6m with yellow, Hibiscus-like, trumpet-shaped blooms. Silver leaves and bark, and a crooked trunk. Good in containers and as a bonsai.
• Tabebuia heterophylla (pink trumpet tree): Fast-growing Caribbean tree to 8m. Yellow-throated, pink funnel-shaped flowers appear in profuse clusters.
• Thalia geniculata (bent alligator-flag, arrowroot, fire-flag): South American/African aquatic plant to 3m. Large grey-green, banana-like leaves on long stalks. Panicles of even longer violet flowers. Young leaves and roots are edible.

Growing exotic plants from seed – V is for Veitchia

• Veitchia (Adonidia) merrillii (Christmas palm, Malina palm): SE Asian palm to 8m with scarlet fruits in winter. Plants have 5-7 fronds when young, building up the crown to 10-12 fronds when mature.
• Veitchia montgomeryana (Montgomery palm): Native to Vanuatu, palm to 10m with yellow or white flowers. Threatened by habitat loss in the wild.
• Vangueria madagascariensis: Madagascan branched shrub or small tree to 5m. Scented greenish-yellow flowers followed by smooth, shiny, brown fruits.

W is for Wallenia

• Wallenia laurifolia (Dominican beauty): Caribbean shrub to 3m with fragrant, white flowers followed by bunches of bright red berries. Rare in cultivation.
• Wodyetia bifurcata (foxtail palm): Native to Queensland, this palm to 10m, was only discovered in 1978. Long 2-3m plumose leaves, grey trunk, large orange fruit.

For more details on growing exotic plants from seed, Chiltern Seeds sells many of these varieties separately.