Learn About Roses

Posted in: Roses
Learn About Roses

How to Plant

Planting Bare Root Plants:

  • Choose a site with at least 8 hours of sun each day, where roots will not be in competition with the roots of other plants. Avoid areas where plants are not protected from harsh winds and cold. Plant climbers where they may be adequately supported. Roses grow well in rich, moisture-retentive soil.
  • Amend the soil 8-12 inches deep with well-rotted compost before planting.
  • Soak roots for several hours in lukewarm water
  • Trim off any broken or damaged roots
  • Dig a hole 18 inches deep and 18 inches wide.
  • Build a cone of soil at the bottom of the hole to support and spread roots around before backfilling
  • In cold winter zones, set the plant so that the base of the canes (bud union) is 4 inches below ground level. In warmer zones, the bud union should be just above ground level.
  • Replace the soil, firming it well around the plant with your hands.
  • Water very well
  • Apply 2-3 inches of organic mulch to keep the soil cool and moist

Planting Potted Plants:

  • Choose a site with at least 8 hours of sun each day, where roots will not be in competition with the roots of other plants. Avoid areas where plants are not protected from harsh winds and cold. Plant climbers where they may be adequately supported. Roses grow well in rich, moisture-retentive soil.
  • Amend the soil 8-12 inches deep with well-rotted compost before planting.
  • Dig a hole for each plant large enough to amply accommodate the root ball.
  • Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
  • Water deeply. The water will seal off any air pockets around the root ball.
  • After planting be sure to mark the plants with plant labels so you know where they are and what varieties they are.
  • Apply 2-3 inches of organic mulch to keep the soil cool and moist.

How to Grow

  • Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients. Control them by either cultivating often or use a mulch to prevent their seeds from germinating.
  • Keep plants well-watered during the growing season, especially during dry spells. Plants need about 1-2 inches of rain per week during the growing season. It's best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated. Keep soil moisture steady when plants are in bloom. Water on bright sunny mornings to give foliage enough time to dry out.
  • Use a slow release fertilizer at the recommended rate. Repeat bloomers need a steady supply of nutrients through the season.
  • Deadhead spent blooms to increase repeat blooming and keep plants tidy. Cut back dead flowers to the first five leaflet leaf.
  • To protect plants from harsh winter cold, mound the base of stems with 8 inches of shredded bark once winter sets in. In areas with severe winters, provide waterproof cover over the top.
  • Prune out dead, diseased or weakened stems at any time. Prune for shape, size or to improve air circulation in late winter after danger of a hard freeze. See pruning tips below.
  • Monitor for pests and diseases.

Growing Tips

  • Winter pruning of shrub roses: Prune when the season starts to warm up and the buds begin to swell. During the first year, prune plants only lightly, leaving two thirds of the plant. Once the plants are established, prune to half their size into a rounded bush. Remove any diseased, dead or weak stems.
  • Summer pruning of shrub roses: Remove 18-24 inches of stem after flowering, leaving 2-3 leaves of the current season’s growth. This helps keep the plant’s height in check, especially in warmer areas where repeat bloomers tend to get taller during the season. Spent flowers left on the plant may develop attractive rose hips in autumn. Stop deadheading towards summer’s end to prevent young, frost-sensitive shoots from developing.
  • Winter pruning of climbing roses: In winter prune the lateral branches that bloomed the previous season to 3 or 4 buds, or about 6 inches ling. Tie in the long, strong main stems and do not cut these back unless they are old, weak or dead. With trellises and other supports, stems can be fanned out to encourage side shoots and more flowering.
  • Cut flowers in the morning. Cut stems back to a five leaflet leaf. Immediately plunge cut stems into water.

Common Disease Problems

Black Spot: This is a fungal disease that affects leaves. It usually occurs in hot, humid or rainy weather. Black circular spots appear on the upper and undersides of leaves. The outer margins of the circles are ragged. The spots can enlarge and merge. The leaves often fall off the plant leaving the plant defoliated. The damage is often worse on the lower leaves. Burpee Recommends: Plant resistant varieties. Remove all debris from under the plants. Avoid getting the leaves wet. A mulch under the plants will help prevent spores from splashing up.

Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.

Crown Gall: This is caused by a bacteria and causes galls (masses of plant tissue) to form on roots, root crowns, stems and branches. The galls can interfere with the ability of water to move through the tissue, affecting plant vigor and causing stunted plants. Burpee Recommends: There is no cure for this disease; remove and destroy infected plants.

Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.

Rose Rosette: This virus-like disease causes witches’ broom growth on roses. Early symptoms include a red pigmentation on the underside of leaves followed by excessive growth of vegetative shoots that are more succulent than normal and red. The leaves become crinkled and brittle with yellow mosaics and red coloring. The leaves become very small. The plant becomes very susceptible to freeze damage. There may also be a proliferation of thorns. This condition is spread by eriophyid mites. Burpee Recommends: Remove and destroy infected plants. Avoid planting roses near multiflora roses, which are alternate hosts. Control eriophyid mites.

Common Pest and Cultural Problems

Aphids: Greenish, red, black or peach colored sucking insects that can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap. Check with your Cooperative Extension Service for suggestions.

Eriophyid Mites: These microscopic mites cause blistered, rust colored or curled leaves, and spread rose rosette disease. Burpee Recommends: Natural predators are available. Check with your Cooperative Extension Service for suggestions.

Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.

Rose Sawfly: The sawfly larva is green with a tan head and resembles a caterpillar. The larva will skeletonize or create windowpane damage to rose leaves in spring and summer. Burpee recommends hand pick the larva off the leaves. Spray plants with insecticidal soap. Check with your Cooperative Extension Service for other suggestions.

Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.

Rose FAQs

My rose leaves are twisted and deformed what causes this?  This may be caused by weed killer that has drifted on to the roses.  Remove affected stems and keep the plant healthy. If the deformed part of the plant is red and stunted with excessive growth of stems and thorns the problem may be rose rosette.

What are good companion plants to plant with roses? Marigolds, geraniums, basil, mint, alliums, parsley are good companions to help repel pests. To avoid root damage plant at least 18 inches away from the roses.

I would like to transplant my rose to a new spot, when is the best time? The best time to transplant your roses is in late winter or early spring while the plant is still dormant before the new growth starts.

Why won’t my rose bloom? There are several reasons why your rose may not be blooming including: not enough sun, too much fertilizer, the soil pH is too low or too high or the plant does not have enough foliage and cannot make food for itself.

What roses produce the best rose hips?  All roses produce hips but the best hips come from Rosa rugosa.

May 21, 2021
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