This article will discuss some of the most common problems, pests, and diseases that impact both young and mature sea buckthorn plants.
Some Common Problems, Pest, and Diseases Affecting Young Sea Buckthorn Plants.
- Drought: Young sea buckthorn plants are especially vulnerable to drought. Although they are typically tolerant of dry conditions once established, they require consistent moisture during their early growth stages. Prolonged periods of water scarcity can lead to stunted growth, wilting, and even plant death.
- Caterpillars and Aphids: These are common pests that can inflict severe damage on young sea buckthorn plants. Caterpillars can chew through leaves, stems, and fruit, while aphids suck sap from the plants, causing yellowing and distorted growth. Moreover, aphids can spread viral diseases, escalating the damage.
- Rodents and Other Mammals: Rodents like mice and voles can gnaw on the bark and roots of young sea buckthorn plants, potentially girdling and killing the plant. Larger mammals like deer can cause damage by grazing on the leaves and young shoots.
- Lack of Nutrients: Like all plants, sea buckthorns need a balanced supply of nutrients for optimal growth. A deficiency in essential nutrients such as nitrogen, phosphorus, or potassium can lead to symptoms like yellowing leaves, poor growth, and reduced fruit production.
Problems, Pests, and Diseases Affecting Mature Sea Buckthorn Plants
- Verticillium Wilt: This soil-borne fungal disease can affect mature sea buckthorn plants. It infiltrates the plant through the root system and causes leaves’ wilting, yellowing, and browning. Verticillium wilt is often lethal, and there is no known cure once the plant is infected.
- Canker and Dieback: These are symptoms often caused by fungal pathogens infecting branches and stems. Cankers are sunken, diseased areas on the outer bark, while dieback refers to the gradual death of branches, starting at the tips. Both can lead to the plant’s eventual death if not properly managed.
- Birds and Mammals: Mature sea buckthorn plants can attract various wildlife. Birds, in particular, are drawn to the plant’s abundant berries. While this may not always be an issue, excessive feeding can strip a plant of its fruit. Larger mammals may also pose a problem by damaging the plant. Deer will often chew on the branch’s new spring growth, or bears might break the entire shrub to get at the berries.
- Root Rot: Another potential issue for mature sea buckthorn plants is root rot, usually caused by overwatering or poor drainage leading to overly wet soil conditions. Fungi that thrive in waterlogged soil, such as Phytophthora and Fusarium species, can infect the plant’s roots, causing them to decay. Root rot symptoms include yellowing or wilting leaves, stunted growth, and, eventually, plant death if left untreated. It’s crucial to ensure your sea buckthorn plants have well-draining soil and are not overwatered to prevent this problem.
Pests Affecting Sea Buckthorn Berries.
Like all other fruit, sea buckthorn berries can be susceptible to various diseases, primarily caused by fungi and bacteria. Here are a few diseases that can cause significant damage to sea buckthorn berries:
- Botrytis or Gray Mold (Botrytis cinerea): This common fungal pathogen can infect sea buckthorn berries. High humidity and cooler temperatures favour its growth. The disease begins as small, water-soaked spots that quickly enlarge, causing the berries to rot and develop a gray, fuzzy mould.
- Powdery Mildew (Erysiphe spp.): While powdery mildew primarily affects leaves, it can also spread to the berries, covering them with a white fungal growth. This disease can decrease the quality of the fruit and may cause it to drop prematurely.
- Anthracnose (Colletotrichum spp.): Anthracnose can cause dark, sunken spots on the fruit, and severely infected berries may rot completely. The disease spreads rapidly in wet, humid conditions.
- The spotted wing drosophila (SWD) fly: Present in most areas of North America, this invasive Asian species has hit the European commercial sea buckthorn fruit market extremely hard. In some years, up to 90% of commercial growers can experience substantial crop losses due to this pest. The fly lays its eggs inside unripe fruit, leaving the larvae to feed and mature under the skin of the berry. The injury to the berry caused by the fly leaves the plant and fruit vulnerable to subsequent plant pathogens. In addition, mild winters seem to be most favourable for this fly’s survival, so the current climate change situation can greatly impact numbers present across many areas of Canada. Ultimately, there are some conventional ways to manage this pest. However, no organic pesticides exist currently. The best practices for natural pest management are to eliminate any non-crop fruits, such as wild raspberry, blackberry, blueberry, mulberry, honeysuckle, and dogwood, that are prime SWD targets in the surrounding areas. Also, regularly inspect crops as the berries begin to ripen and cull any affected fruits. The telltale sign of SWD-affected berries is premature wilting of the berries along the branches.
In summary, despite their hardiness, sea buckthorn plants are susceptible to a variety of problems and pests. It’s important to monitor plants regularly for any signs of these issues and address them promptly, such as providing adequate water and nutrients. For more information on growing sea buckthorn, I invite you to read my other blog articles: Growing Sea Buckthorn 101, and Growing Sea Buckthorn 102.
Following Good Agricultural Practices helps protect sea buckthorn plants from pest invasions, and periodically checking for diseases can ensure that your sea buckthorn shrubs thrive