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Plant Clinic

Pest Alerts

To hear a recording of the most recent Pest Alert, call (406) 258-3820. 

April 23rd Pest Alert Message

Fruit tree blooming.

We are seeing forsythia blooming, but most fruit trees except plums have not started blooming yet. Apple buds are at pink tip now, pears are about ready to bloom. Our warm spring weather has gotten things blooming and coming up early this year.   

You should be close to finishing your pruning now, but if you are not yet, prune on a dry day to avoid spreading disease. It’s to late to apply insect-preventative dormant oil and disease preventative  sprays now.

We are seeing some brown scorched needles on some pine and spruce trees due to winter burn. Most species will mask this damage with the flush of new spring growth. Ponderosa pines were some of the surprising species to be affected this year. Oregon grape also has a lot of brown leaves but they will shed them and flush new growth.

The first aphids are hatching now. If aphids were a problem last year, you can spray with insecticidal soap or neem oil.  Ash Leaf Curl Aphids are hatching and will soon be inside ash leaves. If you had problems with Ash leaf aphids curling Ash tree leaves last year, now is the time to treat for these aphids. The least-toxic option is neem oil or a mixture of insecticidal soap and pyrethrum. Spray ASAP – the spray window is very short. It is still possible to apply insecticide soil injections for ash aphid. The woolly-aphid stage of the spruce gall adelgid is present and laying eggs now. If you had pine-cone like galls on spruce last year, you can spray these cottony, white aphids on alberta and blue spruce and on Doug fir when eggs start to hatch (which will be soon) with insecticidal soap or permethrin.

Soil temperatures are averaging 48 degrees. It’s time to mow lawns. Compost is a good 1:1:1 N-P-K ratio fertilizer that also helps to suppress turf disease problems and build soil structure. This is also a good time to aerate, unless dandelions are blooming in your lawn.

Annual weeds are germinating now. It is a good time to treat them with vinegar sprays. White and cider vinegar can be used on tender succulent annuals; but newly sprouting perennial weeds, such as quackgrass and knapweed are not affected by these low acetic acid concentrations of vinegar. Tillage can also be used to kill newly germinating annual weeds. Till on a warm, dry day so weeds dry out and die.

It’s time to test garden soil and decide what soil amendments are needed. Apply amendments 2-3 weeks before you plan to plant. You can start seeding cool season vegetables now such as potatoes, onions, lettuce, peas, ect.  It’s too early to put out warm season transplants, such as tomatoes.   

If you’ve not done so already, prune June bearing raspberries ASAP. Last year’s fruiting canes will not be leafing out. Prune these canes as close to ground level as possible.

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