Garden Help Desk: What’s happening to the leaves in my anthurium?
We have an indoor anthurium that has leaves that have gone glossy and sticky with tiny brown things all over them. Any idea on what it is and how to help the plant? It doesn’t look healthy and some leaves have started to go light green/yellow.
Your anthurium has scale — tiny insects that feed by sucking carbohydrate-rich “sap” from the plant. That loss of carbohydrates causes untreated infested plants to decline and eventually die. The glossy appearance on your anthurium comes from the excess sugary sap that comes out the back end of the scale as they feed. Scale have many natural predators to keep their populations under control, but indoor plants miss out on that benefit.
Scale and other indoor plant pests like spider mites, aphids, mealy bug and fungus gnats can get into your home and onto your favorite pests when you bring a new plant into the house or when plants that have spent the summer outdoors are brought back inside in the fall. You can reduce problems like this by isolating new plants and reintroduced plants for a few weeks before putting them back near your other plants. It’s also a good idea to do a thorough inspection of any plants that you’re bringing into your home.
The first thing to do now is give your plant a thorough rinsing off. Move your anthurium to your kitchen sink and rinse off the sticky buildup on the plant. Gently rub the leaves and petioles, if needed. Let the plant dry and then you can apply insecticidal soap, 1% horticultural oil, or a 25% of alcohol solution. Remember to rinse and treat both the upper and lower surfaces of each leaf.
The infestation on your anthurium is very heavy. You may want to consider using a soil drench with a systemic insecticide that has the active ingredient Imidacloprid instead of using an oil or insecticidal soap treatment. You’ll need to look for that where you purchase other indoor plant care supplies. It may come as a granular that you apply and mix into the upper soil and water-in, or you might find it as a small stake that you push into the soil. Either way, wear gloves when you handle the product. You’ll find instructions on the label, and you should follow them carefully.
Good plant care is an important part of preventing pest problems. In addition to inspecting and isolating new or re-introduced plants, make sure you’re watering properly for the kinds of plants you have. Most houseplants prefer to have the upper inch or so of the soil dry between waterings and do best with minimal fertilizing, including no fertilizer in the fall and winter. Lighting levels and room temperature are also important.
Healthy plants are less attractive to pests and less susceptible to diseases. Take the time to research what is best for your own plants and give them what they need to stay their healthiest.
The snow has finally melted off in my yard. Can I go ahead and prune my roses now?
Yes! Roses are usually pruned from Late February through early March. Local roses are starting to bud out and most of us in Utah Valley can go ahead and get our roses ready for a new year of blooms. Here are a few basic steps for any new rose growers.
- Before you get started, put on a pair of sturdy gloves
- Brush away any old leaves that are still on the canes
- Cut any dead canes down to their bases
- Prune out any thin, weak canes
- Open up the center by removing all but the 3-5 strongest canes
- Cut back the remaining canes to about knee height or a bit taller
Make your final cuts just above buds that are facing outward from the rosebush. That will direct new growth away from the center of the shrub, maintaining better air circulation in the middle of your rose bush.
After you’ve pruned your roses give them an application of fertilizer to give your roses a good start for the season.