What Grows There :: Hugh Conlon, Horticulturalist, Garden Advisor, and Photographer

Christmas Vs Thanksgiving Cacti

Posted by Hugh on November 26th, 2016

Schlumbergera trucatum

2 year old plant from rooted cutting

Christmas cactus (Schlumbergera bridgesii) or Thanksgiving cacti (Schlumbergera truncata) are called holiday cacti. They are actually succulents and not true cacti. Both originate from tropical regions and make dependable, long-lived house plants.

Christmas cactus are frequently mislabeled as such and are really Thanksgiving cactus. Christmas cacti have flattened leaves with rounded leaf edges compared to Thanksgiving cactus that has pointed teeth.

Holiday cacti are short day plants. They bloom when night hours are 14 hours or longer and daylight hours are 8-10 hours long over 6 consecutive weeks. Bright outdoor lights or room lights may sometimes disrupt the dark period enough that they will not initiate floral buds. In such cases, plants may need to be covered (blackened) or moved into a closet each night.

An alternative method to induce flowering is to expose plants to cool 50-55°F temps. In warm areas in the Southern U.S. and other parts of the world, flowers may not form if night temperatures remain above 68°F regardless of daylength.

Holiday cacti should be repotted annually, preferably in February or March. Water only when potting soil feels dry or once weekly. Mist plants if the room humidity is low. Some flower buds may drop prematurely if room humidity is low or plant is open to cold air drafts. Ideal room temps are 70°F or higher daytime and 55 – 65°F at night. After threat of spring frost has ended, move holiday cacti outdoors into a partly shaded area. Continue to water and feed plants through the summer months.

Mix water soluble fertilizer products such as Miracle-Gro™, Hyponex™, or Espoma™ at one-half the package rate. Withhold winter feeding of plants until most flowers have dropped or restart in late February.

Mealy bugs and soft shell scales are potential problem pests. Overwatering leads to stem and root rots. Plant(s) may be pruned anytime for shaping. Old plants with dead or unattractive branches may be severely cutback after repotting in the spring. Such plants quickly recover.

Announcing AAS Ornamental Winners For 2017

Posted by Hugh on November 23rd, 2016

“Profusion Red’ zinnia (Photo from AAS)

Geranium 'Medium Dark Red' (photo from AAS)

Geranium ‘Calliope Medium Dark Red’ (photo from AAS)

All American Selection (AAS) has named six Ornamental winners for 2017. Some include some new color breakthough in the series that you already know as well as some newbies.

Dianthus ‘Supra Pink’ (Hem Genetics) is an easy-to-grow interspecific dianthus for three-seasons (spring, summer, fall) of garden color. Its mottled, frilly pink flowers stand up to summer’s heat and drought. This vigorous, compact growing cultivar grows barely a foot tall covered with fancy, clear pink flowers. Also try sister cultivar ‘Supra Purple’, a 2006 AAS Winner.

Geranium ‘Calliope Medium Dark Red’ (Syngenta Flowers) has a deep red velvety flower color and great branching habit. All the Calliope® series of geraniums have been top garden performers. This interspecific hybrid has zonal-type flowers and leaves. It displays a mounded, semi-spreading growth habit and strong stems to support the showy flower heads loaded with deep red blossoms. It looks great in containers, hanging baskets and in-ground landscape and handles heat and drought conditions better than most annual geraniums (Pelagonium).

Penstemon ‘Twizzle Purple’ (Van Hemert & Co) is a hardy perennial (Zones 5 to 8) that exhibits vibrant purple blooms, a new and unique color in penstemons. Plant has an upright plant habit and superb flower numbers. The 1-inch tubular flowers form on long slender stalks that stand up to nearly 3 feet in height and are favorites for pollinators from mid- to late summer. Utilize this North American native in combination planters or in landscapes.

Verbena EnduraScape ‘Pink Bicolor’ (Ball FloraPlant) is the first verbena that can tolerate drought and heat plus survive temperatures down to the low teens. This long-blooming pink bicolor verbena is spectacular in a sunny garden, edging a walk or border or grown in large containers and hanging baskets. Vigorous plants spread with abundant soft pink blossoms with darker pink centers. Pink Bicolor is the newest color in the EnduraScape® series.

Vinca ‘Mega Bloom’ is an exciting new series of disease resistant vincas that are withstand summer heat and humidity. Orchid Halo produces huge bright rich purple blossoms with a wide white eye. Plants maintain a nice, dense habit with flowers standing prominently above the dark green shiny foliage. Note: annual vincas (Catharanthus roseus) are frequently called “periwinkles”.

Zinnia ‘Profusion Red’ (Sakata Seed) represents a breakthrough true red zinnia and a favorite of pollinators. The Profusion® series are recognized for their compact form, disease resistance, plus early and continuous blooms all season long. Its vibrant true red color won’t fade in the intense summer sun and heat.

Announcing The AAS 2017 Vegetable Winners

Posted by Hugh on November 20th, 2016

‘Chef’s Choice Yellow’ Tomato (photo from AAS)

‘Antares’ fennel

For 2017 All-America Selections (AAS) has selected these winners in the vegetable category. Each is an outstanding garden performer compared to other varieties that it tested against. Three are national winners and one is a regional winner.

Fennel ‘Antares’ (Bejo Seed) is a national winner. AAS had never before trialed fennel previously. This beautiful plant has multiple uses: as an edible bulb; for its ornamental fronds; as a seed producer; and as a favorite food of pollinators, particularly swallowtail caterpillars. Antares fennel grows very uniform, pure white, and a much improved, almost sweet, licorice/anise flavor compared to other market varieties. It was also 7-10 days slower to bolt compared to other fennel varieties.

Pepper ‘Mad Hatter’ (PanAmerican Seed) is a national winner, chosen for the plant’s vigor, earliness, high yields, large size and fabulous sweet taste. Mad Hatter has a novel three-sided shape. Fruits display a refreshing, citrusy floral flavor and are only occasionally mildly hot near the seeds. Plants grow vigorously with good yields in most areas of the U.S. and Canada. Add to salads raw, pickled or stuffed with cheese.

Tomato ‘Chef’s Choice Yellow’ (Seeds by Design) is a Southeast region winner, the fourth addition to the popular Chef’s Choice tomato series. It produces hearty beefsteak type tomatoes in a beautiful yellow color. Fruits are large and meaty with a sweet, citrus-like flavor, mildly acidic and a perfect tomato texture. The 10-ounce fruits grow on 5 foot high indeterminate vines that are resistant to fusarium wilt, verticillium wilt, mosiac virus, fruit cracking, and scab.

Tomato ‘Patio Choice Yellow’ (Seeds by Design) is a new compact, determinate tomato developed specifically for small garden spaces, including container gardens and hanging baskets. It produces very large yields of 1/2 ounce bright yellow cherry tomatoes on short vines that grow only 18 inches tall. Each compact plant produces over 100 fruits.

Fine Tuning Growing Calamondin Orange In The Home

Posted by Hugh on November 16th, 2016

Calamondin Orange (Variegated Leaf Form)

Calamondin orange (Citris mitis) is challenging to grow in a home environment. It is hardy to 20°F., more than most other true citrus (USDA hardiness zone 8). It does not grow well in temperatures below 45ºF.

In temperate regions calamondin spends the active growing months (May – October) outdoors either in direct sunlight (in northern areas) and in half day shade (in south). Calamondin is moved indoors in winter into a well lit room.

New plants may be easily started from seeds or as rooted cuttings. Flowers are self-fertile and require no cross-pollination. A plant can be forced to flush new growth and bloom by withholding water. Once the leaves show symptoms of wilting, water the plant thoroughly. It should recover full of fragrant blooms within two months.

All citrus plants require iron supplement when soil pH creeps into the alkaline range. Iron becomes less available when soil becomes less acidic. A key symptom of iron deficiency is yellowing of the upper (newest) leaves. Twice yearly, use an iron supplement to maintain healthy green foliage. An alternative is to feed with a water-soluble acidic fertilizer such as Peters™ 20-10-20, Miracle-Gro™, or Schultz™.

Sticky or web-covered leaves may be signs of mite, mealy bugs, and scale infestations. Aphids and white fly may be problem pests in spring. Mealy bugs can be managed with insecticidal soaps inside the home. Otherwise, take the plant outdoors and spray with a pesticide labeled for controlling the specific insect on house plants.

Under optimum growing conditions, annual growth rate is 1 foot per year. Calamondin produces an abundant fruit crop starting at two years of age or when plants are at least 18-24 inches tall. Fruits are usually harvested in the fall.

Calamondin fruits have a thin, smooth, yellow to yellow-orange peel that is easily separable. Ripen fruits are very astringent, but make a tasty marmalade spread for your morning bagel or toast.

Facts About Garden Watering – How Much And When

Posted by Hugh on November 13th, 2016

Tripod rotating sprinkler over new lawn seeding

Irrigation system

Modern gardeners are using more efficient drip irrigation or soaker hoses. Water bills are less than overhead or oscillating systems. You may opt to attach the hose to an automatic timer so you can irrigate in absentia. Water goes on and off anytime you select.

In garden beds water plants deeply once weekly rather than a little bit every day. During the summer months, daily or twice-daily watering may be needed for annuals and perennials growing in hanging baskets, window boxes. Newly planted and large container-grown small trees and shrubs may need a drink.

Over a dry summer, long season vegetables demand deep watering to yield tomatoes, squash, pumpkins, cucumbers, etal. Rhubarb, asparagus, and many perennial herbs need summer moisture to survive cold winters. In late fall rhododendrons, azaleas, blueberries, and other shallow rooted plants should be deeply irrigated before heading into a dry cold winter.

How much water do garden plants require? Most summer annuals need an inch of water weekly—either supplied by natural rainfall or through a hose. Never waste water, no matter how full your city’s reservoir supply; don’t send water down the driveway or street gutter. Mulching plants aids to lower water use.

By mid-July, plants growing in containers require almost daily watering. Some container grown plants like daphnes or hostas are not forgiving if you miss a scheduled waterings, while agaves don’t seem to care. Bigleaf hydrangeas (Hydrangea macrophylla) or ligularias may be seen wilting in the mid-day sun, but fully recover by evening. Repotting plants into larger containers also helps.

Early morning is the best time to water by hand or by an oscillating sprinkler. Plant foliage has adequate time to dry off, reducing potential problems with fungal and bacterial diseases. Disease causing spores require moisture on the leaf surfaces. Snail and slug injury is worse by irrigating in late day or at night.

Finally, the more that you irrigate, nutrients, particularly nitrogen, are leached out of the root zone. New fertilizer must be applied for plants to continue growing and not suffer from nutrient deficiencies. Overwatering leads to root and crown rot problems.

Japanese Larch Is Preferred In Northern U.S.

Posted by Hugh on November 10th, 2016

Larix kaempferi ‘Wolterdingen’ at Chicago Botanical Gardens

Larix decidua at Biltmore Estates, Asheville, NC

Larches (Larix spp.) are majestic deciduous conifers in their northern ranges of their habitat (USDA hardiness zone 4 to 7). However, trees do not prosper in hot and humid summers south of USDA Zone 7.

One of the best is Japanese larch (Larix kaempferi), but unfortunately, it is not commonly planted in U.S. landscapes. The tree averages 50-60 feet in height and 25-35 feet in width. Old specimen trees that are 70-90 feet tall are not difficult to find in botanical gardens in zones 5 and 6.

The tree grows rapidly with an open and pyramidal form and slender, pendulous branchlets. Its fine textured needles are soft to the touch. Bright green needles (to 1 ½ inches long) appear in brush-like clusters at the ends of spur-like shoots along the branches. In autumn needles turn golden yellow and dust the ground around the tree as fine mulch. Flowers appear in March, and the seed bearing cones ripen in October. Also, the 1 ½ inch long green cones feature reflexed bracts that turn brown at maturity.

Japanese larch prefers a fully open site. Soil should be mildly acidic and adequately drained. Larch is intolerant of poorly drained or dry soils, deep shade, and most urban pollutants. Japanese larch is preferred over European larch (L. decidua) because the latter is susceptible to numerous diseases and pests, particularly needle cast, needle rust, canker, and case borer.

Its enormous tree size makes it more suited for large properties such as parks and golf courses. Larch may be planted for reforestation, as a windbreak, or as an individual specimen.

Cultivars: ‘Pendula’ is a popular weeping form in the U.S. ‘Diana’ has contorted, twisted branches; it grows to 6-8 feet tall over the first 10 years, maturing to 20-25 feet high. ‘Wolterdingen’ is a slow growing dwarf shrub and very popular among dwarf conifer collectors.

American Witchhazel Blooms in Autumn

Posted by Hugh on November 7th, 2016

American witchhazel in late October

American witchhazel (Hamamelis virginiana) is the last native flowering plants to bloom in the calendar year. It is a deciduous shrub or small tree, native to woodlands, forest margins and stream banks in eastern North America (USDA hardiness zones 3-8). It typically grows 15-20 feet tall as a multi-stemmed shrub and 30 feet tall in tree form.

Beginning in late September (in Tennessee), branches are covered with tiny clusters of bright yellow flowers. Each flower is composed of 4 strap-like yellow petals. In some years flowers appear before leaf drop and some flowers go unnoticed.

The fertilized flowers form greenish seed capsules that mature to light brown almost a full year later. Seed capsules split open next fall, nearly a year later, and blast (dehisce) seeds 10-20 feet away. Obovate (oval) witchhazel leaves are dark green and average 6 inches in length. Foliage may turn many shades of yellow in fall.

American witchhazel grows in an average, moist, well-drained, mildly acidic soil and in full sun to partial shade. Growing preference is light shade to partial sun and in sandy loam soil. More flowers are produced in full sun than shade. It tolerates compacted and clay soil, but tends to sucker freely to eventually form thickets or colonies; remove suckers to maintain a tidy appearance. Otherwise, little pruning is necessary other than to limit plant height and spread. Pruning is best scheduled for early spring.

Witchhazels have no serious insect or disease problems. Occasional Japanese beetles may damage leaves over a short time, but rarely needs spraying. Deer will browse on the foliage, but cause little serious damage.

Cultivars: There are only a few known selections of American witchhazel. In a trial of various witchhazel clones, Dr. Andrew Bell at the Chicago Botanical Gardens, singled out ‘Little Suzie’ and ‘Harvest Moon’. Both are compact growers and produce abundant flowers. Little Suzie is more dwarf in stature. Harvest Moon drops its foliage early to show off its lemony yellow flowers.

Deerproofing

Posted by Hugh on November 4th, 2016

Deer Enclosure in Waynesboro, VA property

Blueberry planting in separate enclosure (cage)

Deer love to eat most of the flowers, plants and trees in your garden. To discourage deer from eating your garden, you basically have three (3) options.

Construct a Barrier or Fence.
Make your garden unpleasant for deer.
Choose plants that deer don’t like.

Deer Barriers and Fences

Deer can jump an 8 foot fence, but in most cases this height is adequate. Fencing is made from woven wire and polypropylene products. Shorter fences serve as as deterrents and usually effective if deer populations are not starving. Additional deterrents should be considered (read-on). Fences are your costly option and limit your enjoyment of your home landscape. Create a natural barrier such as planting 1-2 rows of thorny shrubs or tall-growing hedges to discourage deer .

Scent Proofing

Commercial sprays are available at garden centers that keep deer away for short periods, 1-3 months. These are strange odors that deer are not accustomed to. Others include Tabasco sauce, mustard, garlic, cayenne pepper, fragrant bar soap, shampoo, et al. Additional short-term remedies are to edge your garden include human hair (ask your barber or stylist for sweepings), fresh garlic, rotten eggs, onions, and mothballs.

Some herbal plants give off a scent that deer usually dislike. They include mint, cloves, sage, yarrow, oregano, citrus, among others.Plant these herbs on the outer edges of your garden to discourage deer.

Deer Proof Plants

Check with your local Extension office for a list of deer-resistant trees, shrubs, and perennials. Plant lists abound in books and on the Internet. However, what may work best in one locale may not in another place. Deer in different parts of the same state may not have similar plant palates. If deer populations are extraordinarily high, they will feed or browse on any plant, some that are not their favorites.

Longwood’s Chrysanthemum Festival

Posted by Hugh on November 2nd, 2016

Ozukuri Mum Display at Longwood Gardens

Mum Display at Longwood Conservatory

As fall mums are finishing up in our gardens, Longwood Gardens in Kennett Square, PA has debut their annual chrysanthemum display in the Conservatory. More than 17,000 chrysanthemums were nurtured and trained, some for more than a year by their talented horticultural staff to resemble balls, spirals, columns, pagodas, and more. It is the largest display of exhibition chrysanthemums in the United States.

The star of the show, the Thousand Bloom Mum or (called “Ozukuri” in Japan), boasts more than 1,500 perfectly arranged yellow flowers on one plant and is the largest grown outside of Asia. Horticulturists grow a single mum plant containing hundreds of perfectly spaced blooms. The Ozukuri display serves as the centerpiece of their annual Chrysanthemum Festival. Visitors will see thousands of mums in 13 different classes and 70 different forms.

The thousand-bloom mum is massive: 12.5 feet wide and almost 8 feet tall. It takes 18 months to grow. They use an heirloom variety from Japan called ‘Susono-no-Hikari’.

Longwood Gardens brags that it’s the largest Ozukuri ever grown outside of Asia. Each year Longwood’s talented staff has increased the bud count: In 2011 — 1,167 flowers, in 2013 — 1,416, in 2015 — 1,509, and 1523 in 2016.

The 2016 festival runs October 15 through November 20. Peak bloom is from November 5-20. Don’t miss this and all the wonderful sights at this year-round Garden Wonderland. Next up is the annual “A Longwood Christmas” from November 24 – January 8, 2017.

Photo by Jane Conlon

Growing Amaryllis

Posted by Hugh on November 1st, 2016

Potted Amaryllis

Amaryllis is a tropical bulb that blooms indoors usually in winter (USDA hardiness zones 9-11). It is one of the easiest flowering plants to grow. Everything you need to enjoy a bouquet of big, beautiful flowers is inside the bulb. Simply plant the pre-chilled bulb in a container and add water.

There are many varieties to choose. Purchase large size bulb (over 30 cm) that produce more bloom stalks and greater numbers of flowers. Local garden centers stock bulbs starting in early fall and offer some already potted. Amaryllis bulbs should be planted immediately or can be stored over several months in a cool (40-50°F) dark dry place prior to potting.

Select a pot with a wide base, large enough to accommodate the new bulb. Fill the bottom of the container with soilless growing media and set the bulb on top. Finish filling and packing the soil-less media within 1 inch of the top. Leave the shoulders and neck of the bulb exposed. Thoroughly water the potting media to settle the bulb. The newly purchased bulb has been pre-chilled and is ready to sprout within 3-4 weeks. Place the pot in a cool (60-70°F) location and in bright light indoors or one-half day morning sunlight outdoors.

Continue to water as needed after shoots and flower buds have emerged. Overwatering will cause amaryllis bulb rot. The large flowers may become top heavy; stake the flower stalk if necessary to support the floral stalk. Blooms last longer if you can keep them away from direct sunlight and dry heat. As the individual flowers fade, snip them off with a sharp knife. Eventually, cut back the entire bloom stalk to about an inch above the bulb. Bloom stalks cut flowers.

Bulb will grow in the same pot and bloom again for several years. When spring frost is over, move amaryllis outdoors to ½ day of morning sunlight and protect from drying winds. Continue to water and feed monthly with a water soluble fertilizer from spring to early fall. Bring the pot back indoors when night temperatures fall below 40°F.

Every 3-4 years in late summer, divide and repot your amaryllis bulbs that have become crowded and pot bound. Stop watering and allow 2-3 months for chilling temps and very low light. The old leaves will dry up and the bulb is dormant. Store the potted dormant bulb in a cool (40°F minimum) garage or storage area.

Amaryllis bulbs make great holiday gifts to garden friends. Brent and Becky’s Bulbs in Gloucester, VA list many colorful varieties in their on-line catalog.