Weigela wine and roses deliver spectacular spring floral displays. The wine and roses weigela in winter doesn’t do much, yet come spring onward, the funnel-shaped flowers in shades of white, pink, and red cover shrubs and beckon hummingbirds.
However, you may wonder why my Monet weigela problems are showing. These deciduous plants are hardy plant staples that are resistant to most problems. The primary challenges for Weigela are a pesky insect, a mold, and sensitivity to a few pesky environmental factors.
In our guide, you can find out more you have weigela leaves turning brown. By the end, you’ll better understand half the weigela diseases and issues that can affect your young shrub and what leads to poor growth. (Learn How Long Does It Take Aloe Vera To Grow)
What Will Stunt Plant Growth on Wine and Roses Weigela?
Soft-bodied insects mealybugs typically gather in bunches to create cottony clusters on weigela. By piercing plant tissues and consuming cell sap, they weaken plants and prevent new growth.
This insect can restrict plant growth and cause green leaves to fall in large infestations. This insect species, the Comstock mealybug, which is most frequently found on lemon trees, may live on weigela.
Treatment is rarely essential because natural predators keep mealybugs in control. However, spraying your garden hose with water or applying insecticidal soap may answer large pest populations.
Botrytis cinerea, a fungus, causes gray mold. This disease attacks weigela blossoms and stems. Lesions on flower petals turn blooms brown, destroying the spring flowery display. Raking wasted debris helps break the life cycle of this disease and is the greatest management since the causative pathogen typically overwinters in diseased blossoms that fall off plants.
Poor water management can drown and edema weigela. Waterlogged soil can drown plant roots. When leaves gather too much water from damp soils, they cannot ventilate or lose it excess water fast enough, developing edema bumps or blisters.
Fertilizer and pesticide overuse can harm weigela bushes. Herbicide injury can be caused by pesticide drift and other garden plants.
Healthy Weigela shrubs reduce environmental damage. Weigela blooms best with optimal flowering in full sun in USDA plant hardiness zones 4–8. Weigela tolerates hard clay soil but needs to be placed where water can drain.
Weigela thrives in normal soil but might be damaged by excessive fertilizer. Follow label instructions when fertilizing. To avoid pesticides blowing onto weigela, spray other garden plants on calm days. (Read Protecting Grass Seed Guide)
Branches Die Back From Frost
Planted Weigelas are hardy to 0° F, but their fragile branches perish from frostbite. The shrub survives this, so before blooming, trim the shrub’s dead branch tips.
Scale On Branches And Foliage
Scale insects have spherical, waxy shells that serve as protection while they eat plant tissues. When you have heavy infestations, shrubs may die. The first sign of a scale infection is frequent darkening of upper leaf surfaces, which is then followed by the leaf drop.
Use a cotton swab dipped in rubbing alcohol to remove the visible lumps from plant surfaces to control minor scale infestations. Spraying is required for severe infestations. Spray “excellent” or mild horticultural oil on the stems and leaves of shrubs. Scale insects and their eggs are smothered by the oil that covers plant surfaces.
Irregular Tan Spots On Upper Leaves
The wing coverings of adult four-lined plant bugs are yellowish-green and have four black stripes, earning their name. They are orangish or reddish in hue in the nymph stage, with black spots and eventually yellow stripes on their wing pads.
These insects produce uneven bronze or tan marks on the leaves near the top of a weigela bush after feeding on them.
Eventually, the affected leaves may turn dark and wither. Spray this bug with encapsulated pyrethrum while it is feeding during the nymph stage for best results every 3 to 5 days until there are no more visible insects.
Discolored Leaves From Root Nematodes
White, transparent, and wormlike, the tiny insect that are then 1/2 inch long, are root nematodes. The weigela’s root system is gradually destroyed as they burrow into the root ball to feed on them.
The planted shrub suffers from stunted growth and a loss of vigor, and as a result, its foliage turns reddish yellow. Although the infected roots quickly perish, the shrub tries to grow new roots above the infected parts.
Established shrubs eventually get infected, too. A stunted, tangled root system that is challenging to water is the end consequence. When there’s more sun outside and the limp shrub foliage doesn’t seem to be recovering well from the sun heat, nematode assaults are most noticeable.
Swollen Growths On Stems
Weigelas with crowns have swollen growths on their roots, stems, and crowns. Crown galls are bacterium-caused growths. In contrast to other plant galls, this bacterium forms cancerous growths.
Plant cancer in this form of the disease is global. Wound-vulnerable shrubs receive gall bacteria. Contaminated tools, soil, water, and splashing rain can cause heavily infected shrubs, so these need to be pulled up and removed to prevent infection from spreading.
Prune out and kill infected canes, twigs, and stems of shrubs, then soak the rest in a solution of a wettable powder antibiotic like Agri-Strep or Agrimycin.
Avoid new plants and nursery stock with suspicious lumps in stems, crowns near the old soil line, or roots.
When cultivating shrubs, avoid damaging the crowns and roots. In a solution of hot water and bleach, disinfect garden tools. Avoid planting sensitive plants in an infected soil site for 5 years.
Branch Tips Brown From Twig Blight
Weigela branch tips turn brown and die back because of blight disease produced by a fungus, killing the entire weigela shrub or branch. Frost-induced brown tips don’t spread after pruning. Shrubs beyond five years old are rarely affected.
When symptoms occur, spray affected shrubs with copper fungicide or lime sulfur fungicide every 10 days in wet seasons. Avoid watering foliage overhead. Prune to enhance air circulation around shrubs. To prevent disease transmission, immerse pruning instruments in bleach.
If twig blight occurs annually, prune and remove affected plant sections in spring.
Leaves Drop Prematurely From Leaf Spot
Weigela is occasionally afflicted with fungal leaf spot infections. The straw yellow or brown leaves of shrubs that are affected are heavily speckled with tiny black fruiting bodies. These diseases typically affect foliage that has already been damaged by another factor. To combat leaf spots, remove and destroy all sick and fallen leaves from the bush’s center.
You should also remove and destroy any dead branches that are there to improve airflow. Anti-transpirant spray should be applied to foliage early in the spring before growth begins.
This layer on the leaves keeps fungus away. Improve the soil’s fertility and drainage around the shrub. Mulching aids in preventing the disease’s spread to plants by preventing it from splashing up from the ground. (Read Do Deer Eat Potatoes)
Leaves Yellow And Wilt From Root Rot
The root and stem rot of Weigela is caused by soil-dwelling fungus. Typically, attacks on shrub stems occur at or very close to the soil. Foliage turns yellow, wilts, and dies without being in full sun.
Usually, rotting root systems cause plants to fall over. Cut away affected plant portions using a clean, sharp knife or razor blade, or remove and trash the infected shrub. Use a household disinfectant to clean instruments after use or soak them in a water and household bleach solution.
Keep mulch away from plant stem bases and old plant debris out of the garden. Make light soil with a combination of perlite, vermiculite, or peat moss for long-term prevention, and give good drainage. Do not overwater. To prevent crowding, space plants widely apart.
When your plants sit in full sun, they use water faster than they can absorb it. Thus, leaves become dehydrated when sitting in the sun for too long and can end up scorched.