Doritis pulcherrima

One of the most reliable orchids for late summer and fall blooms is Doritis pulcherrima. Even the smallest plants rarely fail to send up a spike each year.
This genus is closely related to Phalaenopsis and much hybridization between the two has been done over the years. The Doritis genes bring smaller plant size and a more erect flower spike to their progeny.
The natural species usually only has a leaf spread of 4-6 inches and several plants can grow comfortably together in a 4-inch pot.

They multiply by clumping so it's typical to see plants grouped together in a single pot. When they fill the pot it's time to divide them, giving each one its own space. I like to divide in the spring, giving the young plants all summer to get established and ready for the annual bloom.
Individual flowers are about 3/4 inch across, with petals strongly recurved back toward the stem. The blooms open a few at a time, progressing up the spike, which continues to elongate as new buds are produced. The flowering period easily lasts for 2-3 months, with the spikes often reaching 3 feet in height. In high light the spikes are mostly vertical, but in shade they tend to bend toward the light.

Doritis pulcherrima is a fairly cold-tolerant species and survives brief temperatures in the upper 20°F range if situated under dense trees or shrubs during cold snaps. It also tolerates higher light and drier conditions than its Phalaenopsis relatives.

Turnera ulmifolia

Turnera ulmifolia (TERN-er-uh  ul-miff-FOLE-lee-uh) is an ever-blooming shrub that thrives in subtropical gardens. The bright yellow flowers each last only a day, but new flowers are continuously produced. The plant grows about 3 feet tall in a single season and requires very little care. It is drought-tolerant and thrives in nearly all soil types. The dark green leaves are usually about 2-4 inches in length and the flowers are about 2 inches in diameter.

Turnera ulmifolia is sometimes called yellow alder, but it is not an alder so that is a poor choice for a common name. There's really no reason to call it anything other than Turnera. It is native to the Caribbean and is recommended for USDA Zones 9-11. A hard freeze may knock it back to ground level, but it will quickly recover when the weather warms. In colder locations it can be grown as an annual. The plant reseeds itself easily and you're likely to find seedlings coming up all around the garden. The seedlings are easily identified by the distinctive leaf, so they can be pulled, transplanted, or allowed to remain where they sprout, depending on your preference.

Although you may find seedlings coming up in random locations, they generally aren't prolific enough to become weedy. The flowers attract butterflies, especially Gulf Fritillaries and Sulphurs.

Cuban Oregano (Plectranthus amboinicus)

Plectranthus amboinicus is a tender perennial herb with many common names including Cuban oregano, Spanish thyme, oregano brujo, broadleaf thyme and big thyme.
The leaves are chopped and used with stuffing, salads and meats. It can also be used as a substitute for oregano or sage. If you've picked a few leaves for use in the kitchen and didn't use them all, do not refrigerate what's left. This is a tropical herb and refrigerator temperatures quickly cause brown deteriorating spots. Excess leaves store very well in a sealed plastic baggie or container at room temperature for up to two weeks.
The leaves are large, fleshy and covered with fine hairs.

In full sun the leaves are generally 3-4 inches in diameter, but with a little shade they can easily reach 6" or more in length. Long stems tend to flop over, so keep the plant compact by frequent harvest of the growing tips for use in the kitchen.

This plant is recommended for USDA Zones 9B-11. In areas that experience frost, Cuban oregano is best grown as an annual during the warm months. In frost-free areas the plant is perennial, developing a woody stem at the base and growing about 2 feet in height.

Older plants are not as vigorous, so I like to plant fresh starts each spring that quickly become large specimens. Cuban oregano thrives in sun or part shade. There is also a variegated form that is slower-growing.

Alpinia galanga

Alpinia galanga is the spice that is most frequently used in Thai food. While it is botanically known as a ginger, and is even sometimes known as Thai ginger, for culinary purposes it is referred to as galangal. The flavor is more peppery when compared to ginger root.

The older, tan-colored rhizomes have the most intense flavor, while the new tender sections are milder. If you often flavor your cooking with ginger, this species is a good one to grow because the rhizomes may be dug at any time of the year for use in your favorite recipes. Unopened flower buds are also edible when steamed. 

The large inflorescence of greenish-white flowers is very showy for a short period of time in mid-summer. The canes are evergreen when grown in frost-free locations, and flowers will appear at the tops of the previous year's growth.

The erect canes grow 4-6 feet tall and individual leaves are 2-3 inches wide by 12-14 inches long.

Although they will grow in sun or shade, the plants perform best in moist environments. I had a clump growing for years in a part of the garden with no irrigation. It survived, but barely produced enough rhizomes to keep the clump going, much less have any for harvest. Since I moved the clump to an area that receives over-spray from the nursery irrigation I now have to harvest the rhizomes on a regular basis to keep the clump a manageable size.

Alpinia galanga is recommended for USDA Zones 8B to11.
Use it in curry pastes, stir-fries, soups and tea. Most cooks peel galangal before use. The rhizome is very dense and requires a longer cooking time than ginger, so it is usually cut in thin strips or crushed before being added to a recipe.

The rhizomes have been used in folk medicines to treat a wide range of ailments. It has strong anti-oxidant and anti-inflammatory properties.

Alpinia calcarata

Sometimes called Snap ginger, Alpinia calcarata is a very easy evergreen species that blooms on old growth. Blooms can occur at nearly any time of the year, but peak flowering occurs from late spring to early summer. The inflorescence is carried upright on the end of the cane. Leaves are long and narrow, about 1 to 2 inches wide by 14 inches long.

The thin-stemmed canes arch gracefully from the weight of leaves and flowers. The inflorescence always grows erect, regardless of the degree of arch in the cane.

The clumps grow 3-4 feet in height and spread wider as they multiply. Rubbing or bruising the foliage releases a pleasantly spicy fragrance.

Rhizomes are thin with well-spaced canes.

Alpinia calcarata is recommended for USDA Zones 9-11. It is native to India and grows in sun or shade.
The rhizome is not considered edible, but experimentally, rhizomes of Alpinia calcarata are shown to possess antibacterial, antifungal, anthelmintic, antinociceptive, anti-inflammatory, antioxidant, aphrodisiac, gastroprotective, and antidiabetic activities.

Buy Alpinia calcarata rhizomes

Alpinia nutans

Among the many types of gingers, Alpinia nutans is one that is grown primarily as a foliage plant because it supposedly rarely flowers in cultivation. It may just need the right cultural conditions. As you can see, the flowers are beautiful and it's one of the earliest gingers to bloom in spring. The erect inflorescence contrasts nicely with the dark green foliage.

The flower spikes appear on the ends of mature canes, so don't cut down the foliage in winter or you won't get blooms. 

Unopened buds are soft pink...

and pop open to reveal the vivid red and yellow lip.

This plant is sometimes sold as Dwarf Cardamom or False Cardamom. The foliage has a very pleasant cardamom scent when bruised, but this is not the species that produces the spice called cardamom.

The broad-leafed evergreen canes grow 3-5 feet tall and individual leaves grow about 3½ inches wide by 15 inches long. The canes crowd together in a dense clump and can live for years if not damaged by cold.

Alpinia nutans is recommended for USDA Zones 8-11. In Zone 8 the canes may freeze to the ground in the winter, then send up new growth in the spring. The foliage looks its best when grown in shade to part-sun locations.

Alpinia zerumbet (shell ginger)

Shell ginger (Alpinia zerumbet) is one of the largest-growing of the commonly cultivated gingers, typically reaching about 8-10 feet in height. The pendulous flower spike emerges from the tip of mature canes. It consists of an 8-inch long cluster of individual flowers. Blooms may appear at any time of the year, but they are most likely in spring and early summer.

Leaflets positioned alternately along the canes are dark green and about 4½ inches wide by 2 feet long. The foliage is evergreen and is only damaged by severe freezes.

The bruised leaves are very fragrant. Dried leaves and stems make an excellent addition to dry or simmering potpourris.
The plant spreads by rhizomes and it doesn't take long to form a massive clump. It makes an excellent background or screening plant if you have the room for it. Old dried canes and leaves remain standing for a long time and manual removal is required to keep the plant looking its best.

The large rhizomes are not edible, but the leaves have many reputed uses in folk medicines.
Alpinia zerumbet is native to eastern Asia and is recommended for USDA Zones 8-12. In Zone 8 the canes may freeze back each year before maturity, preventing the production of blossoms.

There is a variegated form of shell ginger that grows about 6 feet tall, and a dwarf variegated form that only gets about a foot tall.

Neoregelia 'Yellow Devil'

Neoregelia 'Yellow Devil' is a very colorful bromeliad variety. If you give it some sun, the plant rewards you with shades of yellow, orange, pink and red. The plants shown here were all grown in full afternoon sun. More of the reddish coloration develops as the plant reaches maturity and starts to bloom.

It grows to be a fairly large plant. In a 6-inch pot the plants get about 2 feet across, but in the ground they'll get even larger. The undersides of the leaves show nice red striations.

Consider viewing it from below by mounting in a tree or growing in a hanging basket.  And when the sun shines through the leaves...

wow!

Neoregelia 'Yellow Devil' tolerates brief temperatures as low as 26°F without any damage.

Plumeria pudica

Plumeria pudica is an evergreen to semi-deciduous species with white flowers that continue to develop whenever the plant is in active growth. A mature plant may remain in bloom for 185 days of the year. The 3-inch diameter flowers are white with a yellow center and emerge in clusters at the stem tips. Plant in full sun for the maximum number of blooms. Unfortunately, the flowers of this species have no fragrance.
Leaves are fiddle-shaped or spoon-like, with a wide lobe at the distal end and coming to a point at the apex. They may be up to a foot long, but are generally smaller unless grown in ideal conditions.

The foliage is evergreen except during periods of prolonged cold or drought. Periodic pruning of the stem tips just before the spring growth will keep the plant full and bushy, especially if done when the plant is young. Mature plants reach about 12 feet in height by 8 feet wide.

Plumeria pudica is native to Panama, Colombia and Venezuela. It is recommended for USDA Zones 9B to 11. This plant is also sometimes known as Bridal Bouquet and Fiddle-leaf plumeria.

Related species: Plumeria rubra

Plumeria rubra

Plumeria rubra and its hybrids are the most widely-grown of the Plumeria species. They come in a wide range of colors and the blooms are generally very fragrant. Each inflorescence may contain between 50 and 200 buds which open a few at a time over several weeks or months.

Flower clusters often appear with the onset of new growth in the spring and may continue to emerge on new growth throughout the growing season. Individual flowers are 2-3 inches in diameter, with some varieties being more prolific bloomers than others. Flowering of all varieties is best in full sun, but the plants do tolerate partial shade.

Plumerias are native to tropical America, but are now grown in warm climates world-wide. In frost-free areas, plants may grow up to 30 feet tall with a nearly equal spread. In climates where freezes occur every few years, plants seldom reach more than 10-12 feet. These plants are recommended for USDA Zones 9b-11, but can easily be grown in containers in colder zones.
Plumeria rubra branches are thick and stubby with persistent leaf scars.

There is a very obvious delineation between this year's new green growth and last year's grayish stem.
Leaves are large (often more than a foot long) and pointed on the end.

This species drops its leaves completely in the winter. All plant parts exude a milky sap when cut, which may irritate the skin of sensitive individuals.
In some areas, Plumerias are commonly known as Frangipani.

Related species: Plumeria pudica