I was hoping y'all could give me help. A friend, who gardens on a 2rd story balcony, has had trouble with her containers. I'm don't know much more than to tell her about cleaning her containers with a bleach solution, use fresh potting mix and make sure there is good air circulation.
Here's what she wrote me:
I was out preparing my containers for the season last night and thought I should contact you, hopefully you can help.
Every year for the past 3 years I have done container gardening on my balcony, I live up on the second story of a condo complex here in Carolina Beach and every year despite my best efforts to smash and wash off I end up with a huge infestation of ants and cottony cushion scale! Is there anything I can do pre season to prevent this again or during the season so I do not have to see these awful things come back again?
Our building is sprayed regularly around the base for ant and I always spray my balcony for ants, but without fail they always come back and it is sooo discouraging! Can you help with any advice or is there a product?
For the ants, diatomaceous earth is an excellent mechanical insecticide, Simply sprinkle around the pots on the balcony deck. Liquid ant baits by Terro are very safe AND effective. http://www.terro.com/products.php?product=liquid_ant_bait The scale is another matter, and treatment can vary by plant. Horticultural oils and systemic treatments (for non-food plants) are options, as is pure cold-pressed neem oil, though there is little in the way of knockdown associated with the neem. It takes a week or two to start realizing results.
DE is a great answer for the ants, I wouldn't have thought of that. I know where she can get that and the ant baits.
I wasn't sure if there was something else besides hort oils for the scale.
Thanks for the help.
Barb, Neem is great but I would be concerned about where the scale is coming from to begin with. Is she starting with clean plants? How about food and water? Pests tend to zero in on plants that are not in optimal health. If she is in a sunny location she would likely have to water twice a day during the hottest part of the summer just in order to keep a plant hydrated much less healthy. Last summer which was a killer, the soil temps in my containers routinely reached the mid 90's and I am in a maritime forest, not a sunny beach. Drip irrigation on a timer saved my sanity.
Have your friend check the building that her plants sit against, Is it brick or plaster? then maybe the insects overwinter in the nooks and cranys of the building too. I have had excellent results with the Neem oil too.
Maybe she could try some different types of plants this year too, ones that won't have as much trouble with the scale.
Will ants hurt plants in containers? I haven't noticed that they do, since I have planted in ant-infested containers (with gloves on!) before. Anyone else know if they will harm some plants, mainly annuals?
The ants themselves won't hurt the plants, but they "farm" insects like aphids and scale that secrete honeydew which the ants like. I think there are some kinds of ants like fire ants that can munch on plant roots, but the ants you have are undoubtedly the sweet-loving ants that are helping out your scale. So if you can get rid of the scale, the ants will probably not hang around as much.
Oh, my, now that's not nice at all...grrrr. I did see all the little holes they made in a planter today, after we planted coleus in it. How do you get them to move out? We have ant poison powder, but I hate to use poison with the kitties out there.
When my pots have ants, I fill a larger bucket with water and sink the pot into it, all the way until the soil is covered by at least an inch. Leave it for a little while until all the air bubbles come out, it won't hurt the plant. The ants head for dry ground. Then drain the pot really good.