Every season brings new challenges and as gardeners, we know this to be doubly true. It seems every month awakens a new garden pest, be it insect, disease, or weather related. To manage these issues it’s important to be armored with knowledge.
This week, our green team gals noticed some tiny yellow creepy crawlers on our butterfly weed. Our plant materials manager, Lisa, checked and confirmed these were Oleander Aphids (OAs). These pests can be easily identified by their characteristic bright yellow bodies and black legs. OAs are often found on Oleander (hence their name), Milkweed and Butterfly Weed. These aphids pierce the plant and ingest sap found in the plants vascular system. As they digest this sap, the aphids secrete a sweet, sticky substance called honeydew. It is not uncommon to notice other insects joining the fun as this secretion is enjoyed by ants, bees and wasps.
The damage caused by the Oleander Aphids begins as mostly aesthetic but can cause some serious harm if left unmanaged. When the honeydew builds up and sits on the plant, it attracts and feeds a black fungus that is both unsightly and detrimental to the plant. Additionally, as the aphids feed they can transmit disease from one plant to another and eventually consume enough sap to stunt growth, deform or destroy your plant.
Although these creepy crawlies can be controlled with pesticide application, it is strongly discouraged as their food of choice is an important resource to pollinators, including the endagered Monarch Butterfly. If pesticides are applied to Butterfly Weed, Milkweed or other host plants, any other insect that visits to feed will be killed as well. Here at Blooms, we opt for an all-natural, albeit tedious, control method – hand picking! OAs are relatively slow-moving insects that can easily be plucked and pinched with your index finger and thumb.
Another type of garden pest may soon visit your garden due to our recent hot and humid weather. Powdery Mildew is a light grey or white fungus that grows on the leaves of plants. If you step out to your garden and ask yourself “who in the world dumped baby powder all over my plants?”, its safe to assume your neighbors are not sabotaging your yard but instead you’ve been visited by a not-so-fun fungus.
Powdery Mildew thrives in hot humid conditions, so it is often noticed in mid-summer when the weather is exceptionally moist. This fungus covers the leaves, stealing nutrients and reducing the rate of respiration which will slow your plant’s growth.
Treatment and prevention are one in the same when it comes to powdery mildew. It is important to increase airflow throughout the canopy of the plant which can be achieved by thinning branches and removing any affected leaves. Keep your plants adequately spaced, especially during humid summer weather and take care to not wet leaves while watering. Remember to always disinfect your shears and tools after pruning or cutting infected plants.