Plant Care and Garden Guide: From Caladium to Cyrtomium
CALADIUM
PLANTING: Outdoors, in the south, set out tubers in the spring when daytime temperatures are at least 70° F. Caladiums prefer a rich, sandy, well-drained soil, enhanced with super phosphate and potash; space bulbs 12 inches apart and cover with one inch of soil. Choose a semi- shaded, sheltered location. Farther north, start in flats or small pots, using 2 to 3 inches of moistened peat moss or a soilless mix as a planting medium. Plant one inch deep with the knobby side up and grow in an area with a temperature of 75 to 80° F., keeping moist. Once rooted, transfer to soil-filled pots; move outdoors to semi-shade once summer has set in. Indoors, grow over the winter in a warm room with high humidity.
MAINTENANCE: Spray foliage and water plant well during hot, dry weather. Remove flowers to prolong life of leaves. In early autumn, gradually dry out the tubers and store in dry peat moss, vermiculite, or perlite at 60°F. Zone 10.
CALLIRHOE
PLANTING: Space plants 18 inches apart in full sun in a sandy loam with a nearly neutral pH of 6.0 to 7.5. Good drainage is essential to prevent the long tap root from rotting.
MAINTENANCE: Water only during periods of prolonged drought. Established plants are difficult to transplant because of the deep tap root. Zones 3-9.
CALTHA polypetala - Marsh Marigold
PLANTING: Plant in full sun in rich, moist to boggy soil or at water’s edge.
MAINTENANCE: Divide plants in spring as needed. Zones 3-8.
CALYCANTHUS floridus - Carolina Allspice
PLANTING: Easily transplanted. Set out about 10 feet apart. Will grow in sun or shade, taller in the latter. Widely adaptable as to soil types, will grow in acid or alkaline soils, but best in a deep, moist loam.
MAINTENANCE: Requires little attention. What pruning is needed is to maintain desirable form should be done after flowering. Zones 4-9.
CAMELLIA - Camellia japonica
Flowering from January to April, this species with glossy 4-inch leaves reaches a height and spread of 6 feet in 10 years with an ultimate height and spread of 10 feet or more. Zones 8-9. Camellia sasanqua - This species is hardier and more open in growth habit with smaller 2-inch leaves. Lightly fragrant flowers appear from September to December, just before C. japonica, to extend the Camellia season. Zones 7-9. PLANTING: Set out plants in the spring or fall in a moisture retentive, acid soil (4.0-6.0 pH) enriched with organic matter. Do not plant deeply; the soil level from the pot should be even with the surrounding soil. Plants grow best in shade but will tolerate full sun if well watered through the summer and during dry spells. In northern areas, it is beneficial to provide extra winter protection by planting near a wall. A western exposure will prevent damage to flowers caused by morning sun hitting frozen flowers.
MAINTENANCE: To maintain a cool, moist root zone, add 2 to 4 inches of a mulch such as pine needles, shredded leaves, or ground bark. Fertilize each spring with an acid fertilizer following label directions. No regular pruning is required. Remove only weak or old wood and dead flower heads after flowering. In northern areas, containerized plants can be moved into a cool greenhouse for winter protection. Keep potted plants moist but not soggy to prevent flower bud drop.
CAMPANULA - Bellflower
PLANTING: Set plants 1 to 2 feet apart, depending on the ultimate size of the species or cultivar you’ve chosen. Plant in fertile, well-drained but moisture-retentive soil, high in organic matter. Campanula will thrive in sun or partial shade.
MAINTENANCE: A light winter mulch is beneficial. In areas where slugs and snails are a problem, an appropriate poison bait is recommended, as Campanula foliage is a favorite of these pests. Taller species or cultivars may require staking. A balanced fertilizer, applied each spring, will promote lush growth, and removal of spent flowers will promote additional flower production. Zones 3-9.
CAMPSIS species and cultivars - Trumpet Vine
PLANTING: Set plants 10 feet apart to allow for ultimate growth. Choose a location in full sun, and a soil that is of low fertility and well-drained.
MAINTENANCE: Water plants during periods of drought. Occasional overhead watering will encourage plants to cling by their aerial roots. An application of a bonemeal or superphosphate in the spring is beneficial for increased flowering. Dead and weak wood should be removed in early spring, as necessary. Shorten lateral branches and cut back overlong tendrils to two or three leaves. Zones 5-9.
CANNA
PLANTING: Plant Cannas 18 to 24 inches apart and 3 to 4 inches deep in a well-drained soil in full sun. They should be planted in the spring after all danger of frost has passed.
MAINTENANCE: Cannas are very easy to grow. They should be watered during dry periods and fertilized during their growing season. Divide every 3-4 years. North of zone 8, after the foliage has be knocked back by autumn frost, dig up the clumps and allow them to dry for several days. Then cover them with dry potting soil, dry vermiculite, or dry peatmoss and store in a cellar or area where the temperatures will remain above 40°F. In the spring, after all danger of frost has passed, they may be replanted. Zones 8-10.
CARAGANA arborescens - Weeping Siberian Pea Tree
PLANTING: Plant 18 inches apart in any good garden soil, in part shade. In the North, they can be grow in in full sun. In the South, most prefer some shade. Most members of this genus do well in moist soils.
MAINTENANCE: Divide in spring if plants become overcrowded. If the foliage looks poor after the winter, cut it back hard in early spring and allow the new growth to come up afresh. Zones various.
CARDIOCRINUM giganteum
PLANTING: Ideal in woodland conditions, in rich, well drained soil very hgh in organic matter and shade to part shade. Plant top of bulb at ground level, and space 4 to 5 feet apart. Bulbs die after blooming, but perpetuate themselves for repeat blooming cycles by producing offsets. Bulbs flower after 6 to 8 years from seed. The bulbs we offer need 2 to 3 years in the ground after planting to reach blooming size.
MAINTENANCE: Protect young foliage from late frosts in early spring. This is a heavy feeder; a heavy top dressing of organic matter mixed with manure is ideal. Zones: 6B -9.
CAREX-species - Sedge
PLANTING: Plant 2 to 3 feet apart, in a loose, well-drained sandy loam well-supplemented with organic matter. Performs best in full sun.
MAINTENANCE: These plants will flower on the current year’s wood. Normally northern winter kills them back; prune back to live wood in early spring, before growth starts. Zones 5-8.
CARYOPTERIS species and cultivars - Blue Mist Shrub
PLANTING: Plant 2 to 3 feet apart, in a loose, well-drained sandy loam well-supplemented with organic matter. Performs best in full sun.
MAINTENANCE: These plants will flower on the current year’s wood. Normally northern winter kills them back; prune back to live wood in early spring, before growth starts. Zones 5-8.
CATANANCHE caerulea - Cupid’s Dart, Love Plant
PLANTING: Set 10 inches apart in full sun. A well drained soil is essential, for Catananche will not withstand water logged soils.
MAINTENANCE: Remarkably drought tolerant -water only lightly during extended periods of drought. Divide yearly to rejuvenate. Zones 4-9.
CENTAUREA species
PLANTING: These plants must have well drained soil and do best in full sun. Space plants 12-18 inches apart.
MAINTENANCE: Water during periods of drought and apply a complete fertilizer in early spring. Plants may be divided every 2-4 years. Zones 4-8.
CENTRANTHUS ruber - Keys of Heaven
PLANTING: Set plants 10 to 12 inches apart. Choose a location in full sun or light shade. Almost any soil will do, so long as it is well drained.
MAINTENANCE: Attention to deadheading will prolong the blooming season and prevent self sowing of unwanted seedlings. Plants may be divided every 3 to 4 years. Zones 4-9.
CERATOSTIGMA plumbaginoides (Plumbago larpentae)- Leadwort
PLANTING: Set plants 15 to 18 inches apart. Ceratostigma will grow virtually anywhere, in good soil or poor, in sun (preferable farther north) or shade, heat or cold.
MAINTENANCE: We recommend a light winter mulch. As plants spread rapidly, frequent dividing may be necessary; this is best done in spring. Zones 5-9.
CERCIS species - Redbud, Judas Tree
PLANTING: Set out in full sun or light shade. Widely tolerant of soils from sandy to heavy clay-loams, Cercis do best in a moisture-retentive, well-drained soil enhanced with healthy amounts of decomposed organic matter.
MAINTENANCE: Mulch to conserve moisture after planting and again each spring for at least the first two years. Provide supplemental water during periods of drought. Both species naturally have a shrub-like growth habit, with many low and upright branches. Prune only to shape or to remove dead branches. Zones various.
CHAENOMELES - Flowering Quince
PLANTING: Set our shrubs in a well worked soil that has been supplemented with organic matter. Plant to allow for ultimate spread of the species chosen. A sunny location will produce the most glorious bloom. These plants also espalier nicely.
MAINTENANCE: Prune after blooming in the spring to shape as desired. A light application of a balanced fertilizer, made at the time of pruning, is beneficial. Zones 4-8.
CHAMAECYPARIS - See Conifers (below)
CHELONE - Turtlehead
PLANTING: Set plants 18 to 24 inches apart in fertile, most soil and in partial shade or sun. These plants do best in consistently wet soil such as around a waterside or bog garden.
MAINTENANCE: Do not allow plants to dry out. Mulch well with compost or manure in early spring. Zones: 3-9.
CHRYSANTHEMUM coccineum - Pyrethrum, Painted Daisy
PLANTING: Set plants 18 inches apart, in full sun to part shade in a rich, well-drained soil. Good drainage is essential; plants may rot in too wet a soil. For best effect, plant in groups of 3 or more.
MAINTENANCE: Remove faded flowers. A winter mulch is beneficial. Divide every 3 or 4 years in spring or fall to prevent overcrowding. Zones 5-9.
CHRYSANTHEMUM maximum - Shasta Daisy (Leucanthemum)
PLANTING: Set plants 12 inches apart. Choose a sunny location, where the soil is deep and rich.
MAINTENANCE: Attention to deadheading will extend the blooming season. We recommend an annual application of a balanced fertilizer, applied each spring before growth begins. Plants should be lifted and divided as needed to assure vigor. Zones various.
CHRYSOGONUM virginianum - Golden Star
PLANTING: Plant 12 inches apart in sun or light shade, preferably in a rich, moisture-retentive yet well-drained soil enriched with compost or leaf mold.
MAINTENANCE: Water well during periods of drought. Divide plants to rejuvenate if necessary. Zones 5-9.
CITRUS species - Lemon, Orange, Kumquat
PLANTING: Indoors, provide at least 4 hours of direct sunlight, a night temperature of 50-55°F, and a day temperature above 68°F. During the fall and winter, allow the soil to dry slightly between each watering. Flowering occurs indoors from mid-winter to early spring.
MAINTENANCE: Pollinate the flowers by allowing a fan to blow across the plant or by gently shaking it each day. Thin the fruit clusters to leave only 2 to 3 lemons per cluster. The plant can be moved outdoors for the summer, where it should be gradually exposed to stronger sun over a period of 4 or 5 days to prevent sunburn. Water every few days, depending on the weather, to keep the soil evenly moist. From early spring through late summer, use a water soluble fertilizer, according to label directions. Pinch as needed to control the size of the plant. Repot as needed, using quality potting soil and a pot that is few inches larger. Zones 9-10.
CLETHRA alnifolia - Summersweet, Sweet Pepper Bush
PLANTING: Set out shrubs 5 to 6 feet apart to allow for ultimate spread. A location in sun or light shade, where the soil is moisture-retentive, enriched with organic matter and of slightly acid reaction is best. Perfect for seaside plantings.
MAINTENANCE: If pruning is desired - to attain a hedge effect, for example - plants may be pruned in the early spring. We recommend a summer mulch to conserve moisture and deep watering during periods of drought. Zones 3-9.
COLOCASIA esculenta
PLANTING: Plant in a 5- to 6-inch pot to allow the roots to continue to develop and place in a sunny window for about a month. Water once every 5 to 7 days to keep the soil damp but not overly wet. Young plants that are not well rooted can be easily over watered, which can cause root rot and death. After about a month, transplant into a larger container (10 to 15 inches in diameter) and place in full sun or plant into the garden, 3 to 6 feet apart in a moist to boggy soil that contains plenty of organic matter. Water every 3 to 4 days to keep the soil damp. Larger plants (especially those in pots) may need to be watered daily in hot areas.
MAINTENANCE: In the colder half of zone 7, small plants are best moved indoors for the first winter; larger plants should be mulched heavily with pine needles, salt marsh hay, or shredded leaves. In areas north of zone 7 where it is not hardy, move indoors to a bright room in the fall and grow as a houseplant. If space is not available, it can also be cut back close to the soil line and stored as a dormant plant in a cool, dark basement. Check the soil every 4 to 5 weeks to keep it barely damp. Zones 7-10.
CONIFERS
PLANTING: Space plants to allow for ultimate growth (though most conifers can readily be transplanted later.) Choose a location that offers full sun (golden varieties and some blue-green varieties might prefer light shade and a location that is somewhat sheltered), and a soil that is well-drained but with plenty of organic matter mixed in. Prepare an ample hole, set plant so the soil level of the root ball is level with the surrounding soil, fill in the hole, firm soil well and water in thoroughly. Mulching is strongly recommended.
MAINTENANCE: Water during extended periods of drought, especially with container specimens. Prune at least once a year, and more where appropriate to develop and maintain shape. Conifers may be pruned at any time of year, except in late summer as this will induce new growth that will not have the opportunity to harden before winter. Zones various.Prune in early winter after the tree has gone dormant to encourage more fruit production next season.
CONVALLARIA majalis - Lily-of-the-Valley
PLANTING: Plant 6 inches apart, covering the “pips” or crowns to a depth of 1-inch and setting them firmly in the soil. A moist soil, but not a heavy clay or one with standing water, is ideal. Best results areobtained in partial to nearly full shade, but Convallaria will succeed in sun, as long as provided adequate moisture.
MAINTENANCE: Annual top dressings of rotted manure, compost or leaf mold, applied in the fall, will make for more vigorous growth and heavier flower production. Can be transplanted by lifting square sods containing a number of plants, or divided singly, primarily to establish new beds. Zones 3-7.
CORDYLINE - Dracena
PLANTING: Container grow in well drained potting mix with bright or lightly filtered light. These plants are most colorful if they receive at least 4 hours or more of direct sun. Water thoroughly at planting.
MAINTENANCE: After the plants are well established begin fertilizing bi-weekly with a house plant fertilizer. Use as patio plants north of zones 9-10 and move inside when the night temperatures drop below 60°F and grow in bright indirect light with 65-70°F night temperatures and 75-80°F daytime temperatures. High humidity (60%) is essential with these plants so keep the plants on a tray filled with pebbles and water. Zone 9-10.
COREOPSIS species and cultivars
PLANTING: Set plants 10 to 12 inches apart, or more for larger cultivars. Choose a location in full sun or very light shade; any reasonable soil, so long as it is well-drained, will do.
MAINTENANCE: Periodically removing spent flowers will lengthen the blooming season. We recommend a mulch of humus or compost. Dividing every 2 or 3 years as it becomes necessary will induce stronger growth. Otherwise, plants are pest- and disease-free, requiring no special care. Zones various.
CORNUS alba - Westonbirt Dogwood, Siberian Dogwood
PLANTING: Set 8 feet apart (3 feet for hedge use), in well-drained, slightly acid soil, enriched with organic matter. Provide full sun to part shade.
MAINTENANCE: Keep plants well-watered. To preserve moisture and protect roots, mulch after planting. Protect against hard winds. Prune to 1 foot from the ground in spring to encourage well-colored new growth. Zones 3-8.
CORNUS alterniflora
PLANTING: Plant in sun or light shade in a humus rich, well drained neutral to acidic soil.
MAINTENANCE: Mulch to conserve moisture and keep well watered during periods of dry weather. Zones 4-7.
CORNUS canadensis - Bunchberry
PLANTING: Set plants 12 to 15 inches apart, in well-drained, slightly acid, humus-rich soil; enrich soil if necessary with peat moss, compost, or leaf mold. Partial shade is preferred, though more sun may be tolerated in the North.
MAINTENANCE: Keep plants well watered. To preserve moisture, we suggest providing a summer mulch. To increase plants, divide in spring or fall. Zones 2-7.
CORNUS florida - Flowering Dogwood
PLANTING: Plant in sun or partial shade; the further South, the more shade is required. An acid soil, well-drained but moist, suits best. Dig a hole amply large to accommodate spreading the roots, fill in and firm the soil down well. Water thoroughly and apply a mulch to conserve moisture, particularly the first year.
MAINTENANCE: The two main causes of failure with Flowering Dogwood are very bad drainage and its converse, allowing the plants to dry out. Site preparation or selection will minimize the former problem, while watering freely during periods of drought will keep the plants in good growing condition. Dogwoods are troubled by borer, and a spray program, as recommended by your county agent, is worthwhile investigating. Apply a balanced fertilizer in the spring, and cut out dead wood after new growth has been made. Zones 5-9.
CORNUS kousa and cultivars - Chinese Dogwood
PLANTING: Set plants 15 to 20 feet apart in slightly acid (pH 5.5-6.5) well-drained yet moisture-retentive soil in full sun to light shade.
MAINTENANCE: Mulch to conserve moisture and to provide a cool root run. Keep well-watered, especially during periods of drought. Prune in early spring, but only to shape. Zones 4-9.
CORNUS x Rutgersensis - Stellar Dogwoods
PLANTING: Set plants to allow for ultimate growth, which is about 15 to 20 feet across. They are at home in partial shade but will flourish in full sun, particularly farther north. Choose a soil that is acid, well-drained and high in organic content - good drainage is essential.
MAINTENANCE: Mulch to conserve moisture and to provide a cool root run. Keep well-watered, especially during periods of drought. Prune in early spring after flowers fade, but only to shape. Zones 5-8.
CORNUS sanguinea - Bloodtwig Dogwood
PLANTING: Plant in sun or partial shade in a moist but well drained soil.
MAINTENANCE: Mulch to conserve moisture and. Prune in early spring as needed.
CORYLUS avellana ‘Contorta’ - “Harry Lauder’s Walking Stick”
PLANTING: Plant in full sun to light shade, in a soil that is well-drained yet moisture-retentive.
MAINTENANCE: Prune only to maintain an open center so the plant’s unique branches can be seen to best effect. This should be done in late winter, during the dormant season. Zones 4-8.
COSMOS atrosanguineus - The Chocolate Cosmos
PLANTING: Plant tubers 6 inches deep and 12 inches apart. Well-drained, medium textured, moisture-retentive soil is best. Requires full sun.
MAINTENANCE: Mulch deeply in winter where plant is hardy. Growth starts late in spring when soil has had time to warm up. May have to stake if plant becomes too full. Where not hardy, dig tubers before first frost and store in a cool, dry frost-free location in dry potting soil or dry peat moss. Wait until the last frost date has passed before planting outdoors again. Zones 7-10, or warm Zone 6.
COTINUS species - Smoke Tree
PLANTING: Plant 8 to 10 feet apart for C. coggyria, 20 feet for C. obovatus. Full sun and any well-drained location provide the best growth.
MAINTENANCE: Maintain a mulch year round to conserve moisture, particularly during the first couple years of growth. Water during periods of hot, dry weather. Prune only to remove weak or dead branches. Zones 4-8.
COTONEASTER species
PLANTING: Space plants to allow for the ultimate growth of the species you’ve chosen. Widely tolerant of soil types (including alkaline soils) so long as drainage is good. Cotoneaster will do best in full sun in the North, and in partial shade in the South.
MAINTENANCE: Prune to shape as needed; any such pruning should be done in late winter or early spring. Zones 5-9.
CROCOSMIA hybrids
PLANTING: Set plants 6 to 8 inches apart. Choose a warm, sunny location where the soil is well drained. The corms should be planted 2 inches deep.
MAINTENANCE: As they grow, old corms remain attached to new corms above. The plants do not spread this way; instead they spread through the formation of rhziomes-i.e., in two years there will be 3 or 4 plants where originally there was one. Corms thus should not be divided. We recommend a heavy winter mulch, particularly in the northern portion of their range. Plants should not be subjected to intense summer heat and drought. In areas with hot summers, light afternoon shading and supplemental watering is advantageous. Zones 5 (with portection)-8.
CRYPTOMERIA japonica - Japanese Cedar
PLANTING: Space plants 20 feet apart in full sun or light shade. Space dwarf varieties 4 to 6 feet apart. Provide an average to light, moisture retentive soil that drains well. Shelter from cold winter winds, especially in colder climates.
MAINTENANCE: Water during periods of drought. Zones 5b-9.
CUPRESSUS species
PLANTING: Site plant in well drained soil in full sun. These plants will tolerate either acidic or slightly alkaline soil.
MAINTENANCE: Protect from cold drying winds. Trim back new growth as needed in late spring. Zones 6-9.
X CUPRESSOCYPARIS leylandii - Leyland Cypress
PLANTING: Plant in full sun, in a light, well-drained loam or peat soil relatively free of lime. Should grow about 5 feet each year; plant 4 feet apart for hedge use.
MAINTENANCE: Mulch after planting, and repeat for at least the first two years for maximum moisture conservation. Water well during periods of drought. We also recommend adequate winter protection against harsh winds and alternate freezings and thaws, especially in cooler areas of its range. Pruning - can shape as desired. Zones 6-9.
