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

Storing Vegetables Outdoors Over The Winter

Posted by Hugh on October 7th, 2014

Use covered cold frame for vegetable storage in winter

In early fall before killing frost arrives, harvest of fresh vegetables is central on gardeners’ minds. You might consider storing some (not all) vegetables outdoors to take advantage of frigid winter temperatures ahead. Limited refrigerator space in your kitchen is not taken up.

Some root vegetables- namely beets, carrots, rutabagas and parsnips- are long keepers. These vegetables store best when harvested near, but not past, their maturity. To maintain safe eating quality, veggies need to be stored within a narrow temperature range between 33 and 40° F.

Carefully gather root crops without bruising or cutting the edible portions. Use a sharp knife to pare away stems and leaves. Gently wash away most of the soil from roots. Cover in damp sand or blanket with a 6 inch layer of loose (not packing) tree leaves or organic mulch.

A second option is to build your own root storage bin in a shady area near the home. Pack the vegetables into a tub, wooden box, 5-gallon bucket, or a plastic storage box (punctured with drainage holes). Start by placing several inches of moist sand on the bottom of the container. Lay a single layer of root vegetables that are not touching one another on the sand. Cover them completely with sand.

If the box is deep enough, add another layer of veggies and sand layer until box or bin is nearly full. Finish covering with a layer of moist sand. Plan accordingly as a full container may likely be too heavy to lift. When you are preparing a meal, remove stored vegetables as needed over the fall and winter months.

If you live in a cool (not frigid) winter climate, overwinter cool crops (broccoli, cauliflower, kale, cabbages, head lettuce) in a cold frame. Cover the harvested crops with a 6-12 inch layer of loose straw or leaves. No part of the green vegetable tissue should be left exposed. If covered with the glass slash, place a cloth blanket over so the sun does not heat up the cold frame. Plan to consume all veggies before the cold frame is needed to start new vegetable and flower plants in late winter.

Planting Of Norway Maple Declining In U.S.

Posted by Hugh on October 4th, 2014

Dark green foliage of Norway maple

Fine grain bark of Norway maple

Norway maple (Acer platanoides) is a hardwood tree native throughout the of Europe and widely planted in the U.S. (USDA hardiness zones 4-7a). At maturity a tree reaches 40 to 50 feet in height (to 75 to 80 feet is not unusual) and 35 to 50 feet in width. Its dense leafy canopy values it a shade tree for planting along streets, large residential properties, golf courses, and in parks.

Norway maple prefers full to partial sun and grows best in moist, well-drained soils. Established trees tolerate hot dry conditions. It transplants reliably and tolerates urban air pollution and moderately compacted soils.

Leaves are 3-5 inches long and 4-7 inches wide. The 5 palmate-lobed leaves are sharply pointed. Yellow fall leaf color is rarely stunning except in specific cultivars. Upper leaf surface is medium to dark green, and dull green, shiny, and hairless underneath.

Small yellowish green flowers appear from early to mid-spring (depending on location) and give way to 2-winged 1 ½ inch wide samaras fruits that whirligig to the ground in fall and winter.

Many cultivars are available at nurseries and garden centers. Norway maple has declined in popularity because seedlings germinate freely along roadsides and woodland areas, competing with native vegetation in the Northeast U.S.

Norway maple has few serious disease or pest problems. Tree is susceptible to verticillium wilt on dry clay soil sites. Its shallow root system frequently cracks or lifts driveways and sidewalks and competes with lawns. In northern areas, bark of young trees may be susceptible to sunscald and frost cracking over the winter months.

Cultivars:

‘Cleveland’ grows 40 to 50 feet high and a narrow 30 to 40 feet wide. Upright branching of young and middle-aged trees is ideal form for urban street planting.

‘Crimson King’ is a popular selection that grows 40 to 50 feet tall and wide; its purple-green spring/summer foliage darkens to maroon or bronze color in autumn. Cultivar tends to grow slower.

‘Emerald Queen’ is a fast-growing selection with an oval-rounded habit (50 feet high and 40 feet wide) and dark glossy green summer foliage. Bright yellow fall color is better than most.

‘Schwedleri’ grows 40-60 feet high and wide; this popular old selection renown for reddish bronze spring foliage which fades to greenish-bronze by early summer.

Tropical Looking Big Leaf Magnolia

Posted by Hugh on October 2nd, 2014

Bigleaf magnolia at Daniel Stowe Botanical Garden, Gastonia, NC

Bigleaf magnolia (Magnolia macrophylla) is native to the southeastern United States as far north to Ohio (USDA hardiness zones 5-8). A mature tree attains heights of 30 to 40 feet and develops an irregular pyramidal form. In the northern areas the tree is deciduous and semi-evergreen in the southeastern U.S.

Its enormous size foliage makes it a true horticultural oddity, something different for a residential site. Its unusual leaf size relegates planting on woodland sites where weak branches and extra large leaves are protected from ice and wind storms.

It grows in full sun or part shade and prefers a well-drained, acidic sandy loam. An established tree is moderately drought tolerant. Its large leaves decompose slowly and create a litter problem. No serious insect or disease problems bother this magnolia if properly sited.

A tree may take 10 or more years before first blooms form. Goblet-shaped flowers are creamy white, rose-purple at the petal base, and up to a foot across. They open in early summer, mostly high in the tree and mostly hidden within the dense foliage. Up close, flowers are pleasantly fragrant. Fruit is round to cone-shaped, rose-colored, and nearly 3 inches long; they’re unique, persistent, and attract numerous bird species. When cones open, each red coated seed is held by a thin silk-like thread.

Leaves are alternate, simple, 12 to 36 inches long and 7 to 12 inches wide. They’re bright green above and silvery gray below. Petioles are 2 to 4 inches long. Its yellow fall color rarely stands out. Leaves are intolerant of most urban pollutants.

It is sometimes called large-leaved cucumber tree — a reference to cucumber magnolia (M. acuminata), a deciduous magnolia from the eastern US which has cucumber-shaped fruit. Bigleaf magnolia has round or egg-shaped fruits that bear little resemblance to cucumbers.

Bigleaf magnolia may be purchased from on-line tree nurseries.

Black Gum Should Be Planted More

Posted by Hugh on September 30th, 2014

New Red Leaf on ‘Wildfire’ black gum

Zigzag Growth of ‘Zydeco Twist’ black gum

U.S. native black gum (Nyssa sylvatica), aka sour gum or black tupelo, is a medium to large shade tree. A young tree has an attractive pyramidal habit and dependable fall color. In the past transplanting black gum has been an issue, but modern advances in growing and planting practices have been solved. New cultivars have favorably changed how we rate black gum as a landscape tree.

Black gum is found throughout most of eastern North America, from Ontario south to Florida, and west to Texas (USDA hardiness zones 4-9). It is widely adapted to dry upland sites, but does tolerate periodic flooding. Black gum handles either partial to full sun. It is best planted in moist, well-drained, acidic soil.

Black gum grows 30 to 50 feet tall with a spread of 20 to 30 feet. In the winter its pyramidal silhouette reminds one of pin oak (Quercus palustris). A tree tends to modify its growth leader to a rounded canopy as it ages. Summer foliage is dark green, and in the fall color blends varying from bright yellow, orange, crimson, and purple. A well-established black gum exhibits good drought tolerant and rarely requires supplemental irrigation. Dormant twigs and buds resist deicing salts.

The tree is primarily dioecious, although you may find some bisexual flowers and fruits scattered through a male tree. Ornamentally, flowers are insignificant. Small blue-black drupe fruits are consumed by a variety of birds and mammals in the fall.

Seedling and some cultivar forms are susceptible to leaf spot diseases in wet summers. Take a peak at these five superior blackgum cultivars:
• Red Rage® (‘Hayman Red’) – reportedly leaf spot resistant and outstanding fall color.
• ‘Autumn Cascades’- a weeping form with irregular form and outstanding fall color.
• ‘Wildfire’- new leaves emerge with reddish tint; glossy green summer foliage and red fall color.
• Green Gable™ – strong pyramidal form (50 feet tall and 25 feet wide), glossy green foliage and outstanding fall color
• ‘Zydeco Twist’- slightly contorted, zigzag branches adds to its many ornamental attributes.

The Mighty Bur Oak

Posted by Hugh on September 25th, 2014

Bur oak in early fall in East Tennessee

Bur oak or mossycup oak (Quercus macrocarpa), aka blue oak and mossy overcup oak, is a majestic native oak native to the midwest and eastern U.S. (USDA hardiness zones 3-8). It a member of the white oak group (rounded leaf lobes, no bristly tips). This large sized deciduous oak grows 60-80 feet tall with a broad-spreading, rounded crown at maturity. Specimens over 90 feet tall are not hard to find. This large shade tree is most suited to large residential and commercial properties, golf courses, or parks.

The tree tends to be slow-growing, particularly when first planted. It naturally grows in deep prairie well-drained soils and in full sun. It adapts to a wide range of soil conditions, including bottomlands. Bur oak is often seen growing in calcareous (limestone) upland soils and is remarkably drought resistant. It is relatively intolerant of flooding.

Strings of yellowish-green separate male and female catkin flowers appear in spring as the leaves are emerging. Leaves are dark green and leathery, 6-12 inches long, and 5-9 rounded lobed. In fall leaf color turns a blah yellow-brown. By late September most leaves have often dropped due to secondary disease and past problems. Twigs and the main branches are often ridged with corky wings.

It may take 35 or more years to produce its first acorn crop. Large sized mossy cup acorns, almost 2 inches long, are oval shaped, and fringed by a burry cup that covers 1/2 to 3/4 of the acorn length. Acorns are an important fall-winter food source for wildlife. Acorns (nuts) have low tannin toxicity; it is best to leached or boiled out the tannins prior to consuming lots of them. Its wood is highly valued like white oak (Q. alba).

Bur oak is a long-lived low-maintenance tree. It is susceptible to numerous secondary diseases, none of which seriously injure the tree. It is resistant to dreaded oak wilt (Ceratocystis fagacearum) disease. Troublesome insect pests include scale, oak skeletonizer, leaf miner, galls, oak lace bugs, borers, caterpillars and nut weevils. Bur oak tolerates urban pollution better than most oaks.

My New Favorite Pruning Shears

Posted by Hugh on September 22nd, 2014

Dramm Model #18012 Hand Pruners

When stepping out to work in the garden, a pair of hand pruners (shears) is the first tool in my pocket or belt pouch. A good pair of pruning shears is indispensable to snip off old spent flowers and stems from perennials such as hostas, daylilies, peonies, etal; shrubs like rhododendrons, lilacs, hydrangeas; to clear away encroaching vegetation from a path; remove dead, pest ridden, and diseased twigs or small (1/2 inch diameter) branches.

Over the years I’ve owned a number of pruning shears from top manufacturers. My requirements for a good pruning shears are as follows:

Blades forged from high grade stainless steel, less likely to rust and stay sharp longer
Comfortable hand grips, less prone to cause calluses after heavy use
Colorful hand grips so pruners are not easily lost in the garden
Trustworthy locking mechanism that, when engaged, the blades close and don’t reopen in a pocket or belt pouch. Cutting action does not lock up by a faulty locking clip
Sharp, stay sharp longer, and cut almost effortlessly
Scissor cut and not anvil type

The Dramm model #18012 is the newest hand pruners in my garden tool shed. Dramm, Inc. is a 75 year old company from Manitowoc, WI, best known for their line of premium watering products for the garden. The model #18012 is a lightweight pruning shears that fits comfortably in a small hand. It is designed for cutting small ¼ inch diameter wood and soft green stems. It is not designed for cutting through thick woody branches, but is fabulous for everyday small tasks.

‘Summer Snowflake’ Viburnum

Posted by Hugh on September 18th, 2014

‘Summer Snowflake’ viburnum at UT Gardens in Knoxville, TN in mid-September

Autumn may be coming or has arrived, but spring-flowering ‘Summer Snowflake’, a selection of doublefile viburnum (Viburnum plicatum var. tomentosum) continues to bloom. Native to Japan, doublefile viburnums are in a league of their own. Summer Snowflake grows 15 to 18 feet tall and a narrow 6 to 9 feet width or roughly 2:1 height to width.

Floral clusters of layered white flowers rest on the horizontal branches. Days later, prominently veined green leaves begin to emerge. Blooming is showiest, at its best around the end of April (in east Tennessee), nearly a week after flowering dogwoods (Cornus florida) have finished. Single snowy white flowers measure the size of a quarter, and each flat cyme averages 4 inches across.

Summer Snowflake is uniquely different because its branching tends to be upright and its repeat blooming. The spring bloom cycle is very showy. Secondary flowering extends almost 3 seasons. Bright red berries follow in late summer and fall, and rusty red fall color completes the season. Leaves are prominently veined. Birds quickly devour the small crop of berries.

Summer Snowflake viburnum is at its best in full sun and in a rich loamy well-drained soil. It fares well in partial sun (4 hours minimum sunlight). Shrub exhibits good drought tolerance within 2 years after planting, but repeat blooming declines if summer is exceptionally dry. Disease and insect problems are generally minimal unless shrub becomes environmentally stressed.

Summer Snowflake may be grown as a large specimen shrub or group several together for an informal hedge or screen. It rarely needs pruning except to control shrub size and form.

Sparse fruit load on doublefile viburnum

Autumn/Winter Garden Dressup

Posted by Hugh on September 15th, 2014

Silvery artichoke at Dallas Arboretum

Ornamental cabbage & kale at Dallas Arboretum

It’s fall and many gardeners take leave of their garden until spring. Autumn is a great time to create new color schemes that will carry over into the winter garden. It’s just like spring all over again! Frost hardy flowering plants get their turn, such as pansies, violas, snapdragons, and diascias (USDA Hardiness zone 7), a recent addition to this list. Plant them in containers or in ground beds.

Tough winter foliage plants such as Swiss chard, giant red mustard, bull’s blood beets, artichoke, and ornamental cabbage or kale are great garden companions. Add fragrant evergreen herbs around a porch, deck or patio areas such as rosemary, lavender, sage and thyme.

Design with in fall/winter plants in containers or garden beds. A good container assortment contains various plant forms and leaf colors. Spiky narrow evergreen shrubs such as ‘Green Arrow’ Alaskan cedar (Chamaecyparis nootkatensis), ‘DeGroot Spire’ arborvitae (Thuja occidentalis), ‘Sky Pencil’ holly (Ilex crenata), or ‘Dee Runk’ boxwood (Buxus sempervirens) add height to a bed or container design.

Weeping and spreading evergreens make colorful “spillers” such as yellow needled ‘All Gold’ juniper (J. conferta ‘All Gold’), winter bronze-leaf Russian arborvitae (Microbiota decussata), or green needled Prostrata plum yew (Cephalotaxus harringtonia ‘Prostrata’).

To insure winter survival, blanket the soil with 2 to 3 inches of organic mulch for root insulation and to conserve soil moisture. Prune off dead blooms and unsightly foliage. Flowering annuals, particularly pansies and violas, benefit from bi-monthly feeding with 10-10-10 or equivalent fertilizer or monthly watering incorporating water-soluble Miracle-Gro™, Jack’s™, or Daniels™.

Fall Blooming ‘October Skies’ Aster

Posted by Hugh on September 12th, 2014

‘October Skies’ aster (Photo by Andrea Sessions, Sunlight Gardens, Inc., Andersonville, TN

From Maine to Texas, the aromatic asters (Symphyotrichum (Aster) oblongifolius) are great garden performers in the fall garden (USDA hardiness zones 5–8). The cultivar ‘October Skies’ is one of the best. Plants are covered with lavender blue flowers (up to 1 ¼ inches in diameter) from late September thru late October. Each flower displays a gold button center. Its grey-green foliage smells minty when crushed.

With a low mounding habit these compact asters grow to 18 – 24 inches in height and spread and rarely require pinching. It is shorter and bushier and bluer (flowers) than sister seedling ‘Raydon’s Favorite’. Plant is a vigorous grower with sturdy stems that stand up well when covered with blooms.

October Skies, along with other aromatic asters, excels in full sun. It prefers a moist well-drained, organically rich soil, but adapts to average dry sites. Spring-planted aromatic asters establish quickly and develop good heat and drought tolerance by mid-summer. Asters do benefit to mulching and feeding at planting and once a year in the spring. Asters attract numerous pollinators, particularly many species of butterflies. Deer usually turn their noses up on aromatic asters.

October Skies ranks as one of the easiest to-grow perennials. As a rule, aromatic asters are highly disease and pest resistant. Plants can be cut back in late fall after flowering.

Kingwood Center In Mansfield, Ohio

Posted by Hugh on September 10th, 2014

Mall area leading up to Kingwood Gardens Office and Library

Floral Display at Kingwood

Over the years Kingwood Center in Mansfield, Ohio (60 miles north of Columbus) has been a popular public gardens to visit. Formerly the home of Charles King, the 47 acre former estate garden has been open to the public since 1953. The former King home now houses Kingwood’s administrative offices and horticultural library.

Kingwood is not an enormous property, but is beautifully laid out and cared for. The talented garden staff creates lasting memories through floral displays. Kingwood is blessed with outstanding collections of hostas (Hosta) and daylilies (Hemerocallis). A formal rose garden displays the newest AARS winners from the American Rose Society. The newly redesigned herb garden (we called it the “Peter Rabbit garden”) offers visitors lots of take-home ideas.

Enter the Greenhouse Conservatory and move from house to house viewing tropical, temperate, and desert plants from around the world. In the rear of the greenhouse is fabulous selection of plants for sale; several gems have found a place in the Conlon garden. Displays of flowering annuals are always well-done, best viewed after summer’s heat has pushed the gardens to their peak from early July to autumn frost. Most annuals and perennial varieties are labeled. Past blog readers have seen many photos from Kingwood Center.

Kingwood’s showcase garden is a formal allee’ of shrubbery and hostas edged with colorful annuals. Displays change every summer with colorful begonias, coleus, geraniums, etal. On one side of the manicured grassy mall is a glorious bubbling fountain and on the other end is Kingwood’s offices and horticultural library.

Walk among the majestic trees and shrubs at Kingwood. Ten of my favorites include: bald cypress (Taxodium), dawn redwood (Metasequoia), Amur corktree, Lawson cypress, coffeetree, silver linden (Tilia tomentosa), Alaskan cedar, Japanese stewartia (S. pseudocamellia), red horsechestnut, and a fabulous collection of crabapples (Malus).

A large pond with lots of ducks (and optional feeding stations) delights visitors, young and old as do the peacocks which have full run of the grounds.

Some mid-Ohio craft groups, such as quilt and lapidary (rocks and gems) societies call Kingwood home. On selected summer weekends, members display and sell their handiwork, including artistic crafts and gems.

Location: 900 Park Avenue West, Mansfield, Ohio 44906 • 419-522-0211. Admission fee: $5.00 (non-members).