Hawthorn

Thornless hawthorn: great for garden design

Thornless hawthorn

Thornless hawthorn looks a bit like a crabapple (to which it’s related). It has shiny dark green leaves, clusters of pink-blushed white flowers, and red fruits at the end of the season. In autumn, the foliage takes on a decidedly red tint. The fruits, which resemble crabapples, are also attractive to wildlife. Unlike other hawthorns, this one does not bear the wicked, 2- to 3-inch curved thorns hawthorns are known for.

Plant facts

Hawthorn

Hawthorn

  • Common name: Thornless hawthorn
  • Botanical name: Crataegus crus-galli var. inermis
  • Zones: 4 to 7
  • Size: To 25 feet tall and 30 feet wide
  • From: Areas of North America
  • Family: Rosaceae (rose family)

Growing conditions

Moist Soil

Moist Soil

  • Sun: Full sun.
  • Soil: Moist, but well-drained soil is best, though hawthorns can tolerate various conditions. Avoid especially heavy clay soils or very compacted soils, however.
  • Moisture: The trees are relatively drought resistant. Watering during times of drought will keep up the tree’s appearance. To avoid many disease problems, don’t plant in a site that’s wet.

Care

  • Mulch: Lay a 2- to 3-inch-deep layer of mulch over the soil around the tree. Avoid laying the mulch directly up against the tree’s trunk—leave a several-inch-wide gap to prevent disease problems.
  • Pruning: Prune in winter. Keeping the centre of the plant pruned well to encourage good airflow can prevent many disease problems.
  • Fertiliser: Additional fertiliser is rarely necessary in average soils.

Propagation

Hawthorn Berries

Hawthorn Berries

  • Seed: Collect ripe fruits and remove the seeds in autumn once the fruits fallen from the tree. Soak the seeds in warm water before planting. Plant them in a sheltered spot in the garden or in a cold frame.

Problems

  • Athracnose: If the leaves look scorched and spotted, the cause may be anthracnose. The spots may be grey, tan, or dark brown; dry or slimy. To deter the disease, prune off any infected branches, dipping your pruning tool in a bleach or alcohol solution between cuts. Prune some of the inner branches to keep good airflow in the tree’s centre.
    Aphids

    Aphids

  • Aphids: If plants are attacked by large numbers of very small insects at the tips of the new growth, it’s probably the work of aphids. Try repeatedly spraying them off plants with a stream of water from the garden hose; encourage beneficial insects; apply insecticidal soap or horticultural oil.
  • Cedar-hawthorn rust: Usually looks like leaf spotting that is followed by small masses of rusty-colored powder on the leaves. Infected leaves die by the end of the season. To deter it, avoid getting the foliage wet; make sure there is good air circulation around plants. The disease requires junipers to complete its life cycle; avoid planting hawthorns near junipers.
  • Fire blight: In spring, this disease causes branches and leaves to shrivel, looking as though they were damaged in a fire. The bark may also be darkly coloured. Cankers may form that can ooze out liquid. To deter this disease, control insects that can help spread the disease and don’t plant other susceptible plants—other plants in the rose family—nearby.
    Leaf Spot

    Leaf Spot

  • Leaf spot: In summer or autumn, the leaves become spotted yellowish or with darker coloured spots. Each spot often has concentric rings around it, forming something of a bull’s-eye pattern. To deter this disease, prune the tree to ensure good airflow. Avoid wetting the foliage in afternoons and evenings.
    Leaf Miner

    Leaf Miner

  • Leaf miners: If the leaves look like they have tunnels going right through the middle of them, it is probably the work of leaf miners. To deter this insect pest, destroy affected leaves and mulch around the base of the plants to keep the larva from burrowing into the soil to pupate. Leaf miner damage is more cosmetic than harmful to the plant.
    Powdery Mildew

    Powdery Mildew

  • Powdery mildew: Powdery mildew appears in mid- to late summer and looks like affected leaves have a greyish powdery covering on them. The leaves then drop off. To deter the disease, prune the plant to keep good air flow and avoid wetting the foliage in afternoons and evenings.

Selections:

  • Crataegus crus-galli var. inermis ‘Crusader’. This cultivar grows smaller than the species and has orange-tinted leaves in autumn. It’s also more disease resistant.
  • Crataegus crus-galli. This form has thorns and isn’t considered as desirable as the variety inermis.
Rugosa Rose

Rugosa rose is a beautiful garden plant

Rugosa rose

Rugosa rose produces loads of beautiful, fragrant, rosy violet flowers in early summer and sporadically in late summer and early fall. Hybrid cultivars of rugosa rose have white, light pink, deep pink, and purplish red flowers. This dense-growing, wide-spreading shrub rose is exceedingly cold hardy and disease resistant and has handsome, wrinkled, deep green foliage that often develops yellow, orange, and red tints in the fall. In addition, this rose produces showy fruits, or hips, that provide a bright splash of red-orange through the fall and early winter.

Rugosa Rose Or Japanese Rose

Rugosa Rose Or Japanese Rose

  • Common name: Rugosa rose or Japanese rose
  • Botanical name: Rosa rugosa
  • Plant type: Deciduous shrub
  • Zones: 2 to 9
  • Height: 3 to 8 feet
  • Width: 3 to 8 feet
  • Family: Rosaceae, rose family

Growing conditions

Well-Drained Soil

Well-Drained Soil

  • Sun: Full sun.
  • Soil: Prefers well-drained soil with ample organic matter but tolerates a range of soil types, including clay and sand. Slightly acidic soil pH is best.
  • Moisture: Consistent moisture is preferable, but rugosa rose has fairly good drought tolerance.

Care

Composted Leaves

Composted Leaves

  • Mulch: None, or a 1- to 2-inch layer of organic mulch such as small wood chips, composted leaves, or cocoa bean hulls.
  • Pruning: Rugosa roses take well to pruning, though their thorny stems can make it a daunting experience for the gardener. Prune in spring to reduce height.
  • Fertiliser: Apply a balanced fertiliser once or twice during the growing season.

Propagation

Rosehips Berries

Rosehips Berries

  • You can grow species from seeds. Seeds require a cold stratification period of three to four months. Sow seeds outdoors in the fall, or place the seeds in a plastic bag with some slightly damp sphagnum peat moss and store in the refrigerator for three to four months. Then sow seeds indoors under lights.
  • Propagate cultivars from softwood cuttings taken in mid- to late summer. Treat with a rooting hormone.

Pests and diseases

Rose Black Spot

Rose Black Spot

  • Resistant to rose diseases such as blackspot and powdery mildew.
  • Aphids, mossy rose gall (caused by a small wasp), and Japanese beetles may affect rugosa rose.

Garden notes

  • Rugosa rose is amazingly salt tolerant. It has naturalised along sandy beach areas in New England, where it is sometimes called “salt spray rose.” It also tolerates road salt that is applied in cold climates.
  • Harvest the large, red-orange hips to make jelly. These large, colourful hips give this rose one of its other common names—beach tomato.
  • Mix rugosa roses with other roses, flowering shrubs, small evergreens, and perennials. Or use them as a low hedge or foundation planting.

Additional cultivars

Thérèse Bugnet

Thérèse Bugnet

  • ‘Alba’ (also listed as var. alba): Blush pink buds open to pure white flowers
  • ‘Albo-plena’ (also listed as var. albo-plena): Double white flowers
  • ‘Belle Poitevine’: Semidouble, mauve-pink flowers
  • ‘Blanc Double de Coubert’: Semidouble to double white flowers
  • ‘Dart’s Dash’: Large, semidouble, mauve flowers and showy red-orange hips
  • ‘Fru Dagmar Hastrup’ (also listed as ‘Frau Dagmar Hartopp’): Fragrant, light pink flowers
  • ‘Hansa’: Large, fragrant, semidouble purplish red flowers
  • ‘Roseraie de l’Hay’: Large, fragrant, double purplish red flowers
  • ‘Thérèse Bugnet’: Large, double, medium pink flowers; reddish canes add winter interest

All in the family

Shrub Rose

Shrub Rose

  • Rugosa rose is used in shrub-rose breeding projects because its genes contribute cold tolerance and disease resistance to the resulting hybrids.
  • Rugosa roses originated in Japan, Northern China, and Korea, but they have naturalized in a number of places in North America.
  • The rose family is a huge and diverse group of plants that includes many ornamental and food-producing plants, including apples, peaches, cherries, raspberries, mountain ash (Sorbus), hawthorns (Crataegus), spireas, and, of course, roses.

Mahonia Aquifolium

Creeping mahonia: one for the garden gallery

Creeping mahonia

Forget about trying to grow grass under that big fir tree in your front yard. Plant some creeping mahonia there instead. This glossy evergreen ground cover, native to western North America, can turn a sad patch into a showpiece. Its leaves look like holly leaves—dark green with serrated edges—and they turn purple-brown in the fall. In early spring fragrant yellow flowers appear on the foot-high shrub. Summer sees clusters of edible but sour berries. This isn’t just any old shrub you’re letting loose on your problem spot, either—it’s got credentials. Creeping mahonia is the 2019 Shrub of the Year, according to the UK. They make great design and are ideal if you want something for a garden gallery.

Creeping Mahonia

Creeping Mahonia

  • Common name: Creeping mahonia, creeping barberry, creeping holly grape, dwarf Oregon grape   
  • Botanical name: Mahonia repens
  • Plant type: Evergreen shrub
  • Zones: 5 to 8
  • Height: About 12 inches
  • Family: Berberidaceae

Growing conditions

Plant Grow Seedling Sunshine

Plant Grow Seedling Sunshine

  • Sun: Best in part shade or dappled shade
  • Soil: Average, well-drained, acidic
  • Moisture: Medium   

Care

  • Mulch: Three to six inches of organic mulch will help the soil retain moisture.
  • Pruning: Pull suckers as needed.
  • Fertiliser: None needed.

Propagation

Oregon Grape Mahonia Aquifolium

Oregon Grape Mahonia Aquifolium

  • By seed or division.

Pests and diseases

Mahonia Leaf Scorch

Mahonia Leaf Scorch

  • Vulnerable to leaf spots, leaf scorch, and rusts.
  • Whitefly, scale insects, and aphids can be problems.

Garden notes

  • M. repens spreads by stolons, but it creeps slowly and is not considered invasive and is good for a garden gallery.
  • Dry shade (such as under a large tree) is one of the toughest spots for a shrub, but M. repensthrives in spots like this. In the wild, it’s often found under conifers, where there’s dappled shade and acidic soil.
  • It can also handle full sun, and it’s drought tolerant
  • The evergreen foliage can scorch or burn, so plant M. repens in a place that’s sheltered from winter winds.

All in the family

Nandina Domestica

Nandina Domestica

  • Also in Berberidaceae, or the barberry family, are the familiar garden plants heavenly bamboo (Nandina domestica), barrenworts (Epimedium spp.), mayapples (Podophyllum spp.), and, of course, barberries (Berberis spp.).
  • Several other native mahonias are popular in gardens. The Oregon state flower, Oregon grapeholly (M. aquifolium), grows 3 feet tall and 5 feet wide but is otherwise very similar to M. repens. M. fremontii, a large bush found in the southwest U.S. and Mexico, grows even taller, to about 6 feet tall and wide. Cascades mahonia (M. nervosa), though just a bit larger than M. repens, produces leaves and flower racemes more than twice as long. Asian mahonias like M. japonica and cultivars of hybrids like M. x media are also favourites.