Karla's Pest Advice

Karla wrote to Linden Staciokas who writes the gardening column for the News-Miner to ask about powdery mildew and aphids. She got quite a reply back, but since she still is unable to post on this blog I'm posting it for her. Thanks Karla! ~S

From Linden:

Powdery mildew , as I am sure you know, tends to erupt when air circulation is poor, and nights are cool. Also, excessive nitrogen helps it along. You've done the right thing clearing out all infected debris and not using it the infected stuff in compost. However, the spores can stay on the soil so it is best to spray the area with some of the same fungicide you would use on the foliage of affected plants. Something with neem oil, sulfur, triforine or potassium bicarbonate will work. One thing I used in years past, when I had an outbreak, was a baking soda spray: 1 gallon water, 1 tablespoon baking soda, 2 and a half tablespoons of vegetable oil and 1 tablespoon of liquid dish soap (I like Dawn, but others should do). It can be used on the plants at the first outbreak and I used it on the soil as well. It is probably the least toxic solution. Next year, try not to plant cukes in that area, as they are especially susceptible to powdery mildew, as are strawberries.

Other folks I know swear by compost tea.

Neem works by inhibiting fungal spores from germinating, so it works best as a preventative measure...

Aphids are a pain and when I learned they are born pregnant I wanted to give up the fight entirely. Gardens or greenhouses with a lot of birch trees around are in trouble, as aphids seem to congregate on the bitch and then move on. It will not help to change out your soil, believe me. Here I speak from back breaking, expensive experience...Instead, your attack on them has to be multi-faceted:

You have to keep a daily, sharp eye so that you catch early infestations right away and can either pick them off your greenhouse plants or use an insecticidal soap.

Every time I water, I look under leaves and along the stems to be sure I don't see any aphids. If I do, I cup that part of the plant in one hand and give a sharp blast of water with the other right onto the infected area. (I have warm water piped for my hoses, so it is not as terribly hard on the plants as an ice cold drenching would be.

I also moved my eggplants into their own little tent and that is where they spend the summers now, since they attract aphids that then spread to other plants.

I released lady bugs into the greenhouse several times over the season.

I moved my dahlias, which also attract them, to a new area away from the greenhouse.

Finally, I discovered aphids stowing away on plants I bought at a nursery, so now I always wash transplants for my greenhouse down with insecticidal soap and I don't bring them into my greenhouse until they have spent about a week either in my house or in the garage, so I can check that nothing is hiding at soil level. Ditto for plants I get from friends, as I have found aphids on those plants, too. I once bought a $100 hanging basket as a gift for a friend and stored it in my greenhouse until her birthday about 10 days away. Only the next day did I discover dozens of aphids crawling out and all over the greenhouse. It was nightmare summer that cost me far more than the original $100 I'd spent!

I hope what I have written gives you one or two useful ideas to try. It is a constant battle.

So far, no moose here. I have a fence for the first time this year, so perhaps I will be spared. I also have an Irish Wolfhound that gives great chase and scares them off, so maybe they won't even try outwitting the fence this year, seeing Alistair on the other side of the fence. I have attached a picture of Alistair and my husband, so you see what a formidable anti-moose dog I have! (My husband is nearly 6 feet tall!)

Thanks for writing.

Linden