Archive | July, 2011

Heliotrope

31 Jul

Heliotrope (Heliotropium arborescens), evergreen to deciduous, mounded to spreading 2-3 feet in height, large clusters of very small, fragrant flowers in purple to white most of the year, large deep green to purple-green foliage, sun to part shade, average to little water when established, good container plant.

Species of this genus produce clusters of tiny flowers with a sweet, delicate fragrance. Foliage is handsome. Provide well-drained soil.

Heliotropium arborescens: from Peru. This old-fashioned favorite grows to 4 ft. tall, 2 ft. wide in the mild-winter zones where it is a perennial, but it’s typically treated in all regions as a summer bedding annual to 1 1/2 to 2 ft. high, 1 to 1 1/2 ft. wide. Dark violet, purple, blue, or white blossoms are densely set in curved, one-sided spikes that form rounded, 3 to 4-in. clusters. They have a scent reminiscent of vanilla. Veined leaves have a darkish purple cast.
‘Black Beauty’ and ‘Iowa’ are varieties with deep purple flowers; there are also dwarf forms under 1 ft. high.

All are good in pots (in cold climates, overwinter them in a frost-free spot). They can take full sun in cooler climates but need partial shade in warmer ones.

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Periwinkle

31 Jul

Periwinkle (Vinca minor) evergreen, spreading growth habit 6-12 inches in height with indeterminate spread, flowers in shades of blue and purple to white, dark green glossy foliage, best in part shade, deer resistant.

Trailing, arching stems that root where they touch soil make these plants useful as ground and bank covers. Shiny dark green, oval to oblong leaves. Lavender-blue, five-petaled, pinwheel-shaped flowers appear in leaf joints in early spring. Plant the larger species and its varieties 2–2 1/2 ft. apart, dwarf kinds 1/2 ft. apart. When plantings mound up or are layered with old stems, shear or mow before new spring growth begins. Will grow in almost any soil. Compete successfully with surface tree roots.

Vinca major is the larger, more aggressive species, and should be avoided. Leaves to 3 in. long, flowers to 2 in. across; mounds to 1–2 ft. high. Spreads rapidly; can be extremely invasive in sheltered, forested areas.

 Vinca minor is the dwarf version of V. major, with 3/4–1 3/4-in.- long leaves, flowers to 1 in. wide, and a height of just 4–6 in. More restrained, less likely to invade adjacent plantings.

Dichondra

31 Jul

Dichondra, trailing growth to 1-3 inches in height, indeterminate spread, spreads by rhizomes and roots at leaf nodes, silver-gray horseshoe-shaped foliage, does not produce flowers, full sun to light shade, regular moisture, tolerates light foot traffic.

Native to west Texas through Arizona, Dichondra Silver Falls is a perennial creeper with striking silvery foliage that provides a blanket of contrasting texture and colour for your garden. Dichondra Silver Falls has a true cascading habit that makes it particularly useful for hanging baskets. It may even be used as a lawn substitute.

Tiger Flower

27 Jul

Tiger Flower (Tigridia pavonia), exotic deciduous bulb, very vertical clumping growth to 3 ft. in height, large bright white to orange bowl-shaped flowers in summer, full sun to part shade, drought tolerant, naturalizes, very dramatic flowers last only one day.

Mexican native with flashy summertime flowers. Fans of narrow, swordlike, ribbed leaves to 1 1/2 ft. long send up erect, 2 1/2-ft. flower stems bearing triangular blossoms that can be 6 in. across. Flowers have three large outer segments in orange, red, pink, yellow, or white; cuplike center and three small inner segments are usually boldly blotched with contrasting color. (Immaculata strain is unspotted.) Each flower lasts only one day, but the bloom period usually lasts for several weeks.

Tigridia is a genus of about 30 species mainly from Mexico and Guatemala in the Iridaceae family. They produce a succession of short lived flowers which are usually in bright colours. The rootstock is a tunicated bulb, found from 3 to 15 cm deep in the wild. Bulbs are never found to offset in the wild. Leaves are pleated in a broad fan. The best known species is Tigridia pavonia whose flowers are 10-15cm (4 -6 inches) across in red, orange, yellow or white variously blotched in the centre. They commence growth in spring and generally die back during autumn. Many species are easy to grow in pots, but survive best if protected from rain in the winter.

 

Tigridia augusta, Dennis SzeszkoTigridia chiapensis, Alfredo Gómez LópezTigridia durangense, Rogan RothTigridia mexicana, Dennis SzeszkoTigridia orthantha, Mendocino Coast Botanical Gardens, Mary Sue IttnerTigridia pavonia, Ellen Hornig Tigridia vanhouttei, Dennis Szeszko

Rock Purslane

26 Jul

Rock Purslane (Calandrinia grandiflora), evergreen, succulent shrub, moderate growth to 12 inches in height with a 3 foot spread, mounding growth habit, purple flowers spring through fall, fleshy gray-green leaves, full sun to part shade, drought tolerant, excellent container plant.

A succulent plant, native to Chile, that forms mounds to 1 foot tall by 3 feet wide of fleshy obovate gray-green leaves to 4 to 6 inches long. In spring through fall, rising on delicate 2-3 feet tall stems, emerge the 2 inch wide purple flowers that each last only one day. Plant in full sun to part shade in a well-drained soil with only occasional irrigation. It is hardy to USDA Zone 8 (10-20° F) and is sometimes planted as an annual in cooler climates. This plant has long been known as Calandrinia grandiflora but recently the name Cistanthe has been reinstated for many New World species formerly placed in the genera Calandrinia.

Dwarf New Zealand Flax

26 Jul

Dwarf New Zealand Flax (Phormium tenax), evergreen, clumping to slowly spreading growth to 6 feet, flowers on 4-6 ft. stalk, leaves vary in color from white and yellow to green, deep red, bronze to chocolate, tolerates any soil, sun to part shade, drought tolerant, deer resistant, strong vertical effect.

From New Zealand, this dramatic plant has many swordlike evergreen leaves that grow in a fan pattern; make good garden focal points. The many variegated selections provide year-round color in perennial and shrub borders, on hillsides, in seaside plantings, near swimming pools. Cool weather intensifies foliage colors. On established plants, branched clusters of tubular flowers appear in late spring or early summer, rising to twice the height of the foliage clump in some kinds. Nursery plants in containers are deceptively small; when you plant, allow enough room to accommodate a mature specimen. Cut out flower stalks when blossoms wither.As leaves age, colors fade; cut out older ones as close to base as possible to maintain best appearance. On variegated sorts, watch for reversions to solid green or bronze; remove reverted crowns down to root level before they take over the clump. Clumps can remain in place indefinitely. To increase plantings, take individual crowns from clump edges; or divide large clumps.

Many of these plants become much too large for average Bay Area gardens – be sure to select dwarf varieties in most cases.